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2022 Vol. 40, No. 7
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2022, 40(7): 1-8.
doi: DOI:10.13205/j.hjgc.202207001
Abstract:
Aiming at the attenuation of the control effect on runoff during blockage of a permeable brick system,the output characteristics of heavy metals in permeable brick runoff during the whole process of blockage were investigated,and the integrated pollution index method was adopted to evaluate the pollution risk of heavy metals in the permeable brick runoff with different blockage degrees.The results showed that the output concentration of the dissolved and particulate heavy metals in permeable brick runoff got increased with the increase of blockage degree of permeable brick,and the output concentration of heavy metals in permeable brick runoff increased significantly after the blockage degree of permeable brick reached 30%.The first flush effect of heavy metals in permeable brick runoff during the whole process of blockage all appeared,and the first flush effect of heavy metals in permeable brick runoff was positively correlated with the blockage degree of permeable brick.The heavy metal pollution risk of runoff during the whole runoff period was low in the early stage of permeable brick blockage,but with the increase of blockage,the heavy metals in initial runoff showed high pollution risk,in which Cd and Pb were the main pollution risk sources.
Aiming at the attenuation of the control effect on runoff during blockage of a permeable brick system,the output characteristics of heavy metals in permeable brick runoff during the whole process of blockage were investigated,and the integrated pollution index method was adopted to evaluate the pollution risk of heavy metals in the permeable brick runoff with different blockage degrees.The results showed that the output concentration of the dissolved and particulate heavy metals in permeable brick runoff got increased with the increase of blockage degree of permeable brick,and the output concentration of heavy metals in permeable brick runoff increased significantly after the blockage degree of permeable brick reached 30%.The first flush effect of heavy metals in permeable brick runoff during the whole process of blockage all appeared,and the first flush effect of heavy metals in permeable brick runoff was positively correlated with the blockage degree of permeable brick.The heavy metal pollution risk of runoff during the whole runoff period was low in the early stage of permeable brick blockage,but with the increase of blockage,the heavy metals in initial runoff showed high pollution risk,in which Cd and Pb were the main pollution risk sources.
2022, 40(7): 9-17.
doi: DOI:10.13205/j.hjgc.202207002
Abstract:
For the current obstacles of low photocatalytic degradation efficiency of typical PPCPs such as ibuprofen and the limited reusability restricts,the organic core-inorganic shell structured chitosan-Ag/TiO2(CAT) composite beads were successfully synthesized using chitosan as the carrier and silver-doped TiO2 as the photocatalyst,and used for the degradation of ibuprofen.The results illustrated that chitosan agglomerated tightly to form a core,and the silver-doped TiO2 was distributed on the surface of the chitosan,eventually forming an organic core-inorganic shell structure.The composite beads showed a good removal efficiency on ibuprofen under UV irradiation.The ibuprofen removal efficiency of 96.1% was achievable in 60 min under optimal operational condition (catalyst load=4 mg/L,initial IBP concentration=1 mg/L,initial pH=6).The results showed that even after the fifth photocatalytic cycle,the removal efficiency after 60 min was still as high as 85.0%.Novel core (organic)-shell (inorganic) composite structure and the additional band above the valence band was created by the carbon-contain groups and the doped N species of chitosan,which could enhance the absorption,photocatalysis,stability and reusability of the CAT composite beads.The inorganic shell formed by doping Ag on the surface of TiO2 was wrapped on the surface of the organic core formed by chitosan.So photogenerated electrons transfer readily from TiO2 to Ag with heavy accumulation due to doping Ag on TiO2 surfaces,which may reduce the recombination of electron-hole pairs and thus enhance the photocatalytic efficiency.The reactive species scavenging experiments showed that·O2- mediated reactions and direct-hole oxidation were the major degradation reactions.
For the current obstacles of low photocatalytic degradation efficiency of typical PPCPs such as ibuprofen and the limited reusability restricts,the organic core-inorganic shell structured chitosan-Ag/TiO2(CAT) composite beads were successfully synthesized using chitosan as the carrier and silver-doped TiO2 as the photocatalyst,and used for the degradation of ibuprofen.The results illustrated that chitosan agglomerated tightly to form a core,and the silver-doped TiO2 was distributed on the surface of the chitosan,eventually forming an organic core-inorganic shell structure.The composite beads showed a good removal efficiency on ibuprofen under UV irradiation.The ibuprofen removal efficiency of 96.1% was achievable in 60 min under optimal operational condition (catalyst load=4 mg/L,initial IBP concentration=1 mg/L,initial pH=6).The results showed that even after the fifth photocatalytic cycle,the removal efficiency after 60 min was still as high as 85.0%.Novel core (organic)-shell (inorganic) composite structure and the additional band above the valence band was created by the carbon-contain groups and the doped N species of chitosan,which could enhance the absorption,photocatalysis,stability and reusability of the CAT composite beads.The inorganic shell formed by doping Ag on the surface of TiO2 was wrapped on the surface of the organic core formed by chitosan.So photogenerated electrons transfer readily from TiO2 to Ag with heavy accumulation due to doping Ag on TiO2 surfaces,which may reduce the recombination of electron-hole pairs and thus enhance the photocatalytic efficiency.The reactive species scavenging experiments showed that·O2- mediated reactions and direct-hole oxidation were the major degradation reactions.
2022, 40(7): 18-24.
doi: DOI:10.13205/j.hjgc.202207003
Abstract:
In this study,the removal efficiency of phenolic compounds in coal gasification wastewater (CGW) and biodegradability were investigated by iron-carbon microelectrolysis (ICME) treatment.The results indicated that the iron-carbon composite (Fe/C) filler had a high iron and carbon ratio and rich pore structure,thereby performed higher reactivity.The single factor analysis showed that low dissolved oxygen (DO) and acidic condition were more favorable to microelectrolysis reaction in CGW treatment.However,it was not conducive to ICME reaction when the Fe/C filler content was too high or too low.The response surface method suggested that the optimum condition of the ICME process for phenolic compounds removal was the pH of 6.50,Fe/C filler content of 62.22 g/L,DO concentration of 0.47 mg/L.Based on the optimum condition,the removal efficiency of COD and total phenol reached 80.98% and 75.03%,respectively.The BOD5/COD value of CGW was increased from 0.21 to 0.36.The above results demonstrated that ICME played an important role in strengthening the removal of phenolic compounds in CGW,which provided better water quality for subsequent biochemical treatment.
In this study,the removal efficiency of phenolic compounds in coal gasification wastewater (CGW) and biodegradability were investigated by iron-carbon microelectrolysis (ICME) treatment.The results indicated that the iron-carbon composite (Fe/C) filler had a high iron and carbon ratio and rich pore structure,thereby performed higher reactivity.The single factor analysis showed that low dissolved oxygen (DO) and acidic condition were more favorable to microelectrolysis reaction in CGW treatment.However,it was not conducive to ICME reaction when the Fe/C filler content was too high or too low.The response surface method suggested that the optimum condition of the ICME process for phenolic compounds removal was the pH of 6.50,Fe/C filler content of 62.22 g/L,DO concentration of 0.47 mg/L.Based on the optimum condition,the removal efficiency of COD and total phenol reached 80.98% and 75.03%,respectively.The BOD5/COD value of CGW was increased from 0.21 to 0.36.The above results demonstrated that ICME played an important role in strengthening the removal of phenolic compounds in CGW,which provided better water quality for subsequent biochemical treatment.
2022, 40(7): 25-30,51.
doi: DOI:10.13205/j.hjgc.202207004
Abstract:
Municipal sludge is rich in organic matter,which can provide carbon source for the preparation of graphene oxide (GO).In this paper,GO was prepared from municipal sludge by modified Hummers method.Response surface methodology (RSM) was used to optimize GO preparation conditions,including toner dosage,potassium permanganate dosage,concentrated sulfuric acid dosage,and ultrasonic time,based on single factor experiment.The optimized preparation conditions of GO-based on municipal sludge were carbon powder of 3.22 g,potassium permanganate of 4.12 g,concentrated sulfuric acid of 22.63 mL and ultrasonic time of 7.61 h.Scanning electron microscopy and infrared spectroscopy analysis showed that GO prepared under the optimum experimental conditions had obvious lamellar structure,with O-H (hydroxyl) characteristic peaks at about 3400 cm-1 and 1400 cm-1,C=O (carbonyl) characteristic peaks at about 1700 cm-1,and C-O (epoxy) characteristic peaks at about 1200 cm-1.It was consistent with the properties of GO prepared with the traditional materials.Thus,a new direction and theoretical basis were provided for the utilization of municipal sludge by preparing GO.
Municipal sludge is rich in organic matter,which can provide carbon source for the preparation of graphene oxide (GO).In this paper,GO was prepared from municipal sludge by modified Hummers method.Response surface methodology (RSM) was used to optimize GO preparation conditions,including toner dosage,potassium permanganate dosage,concentrated sulfuric acid dosage,and ultrasonic time,based on single factor experiment.The optimized preparation conditions of GO-based on municipal sludge were carbon powder of 3.22 g,potassium permanganate of 4.12 g,concentrated sulfuric acid of 22.63 mL and ultrasonic time of 7.61 h.Scanning electron microscopy and infrared spectroscopy analysis showed that GO prepared under the optimum experimental conditions had obvious lamellar structure,with O-H (hydroxyl) characteristic peaks at about 3400 cm-1 and 1400 cm-1,C=O (carbonyl) characteristic peaks at about 1700 cm-1,and C-O (epoxy) characteristic peaks at about 1200 cm-1.It was consistent with the properties of GO prepared with the traditional materials.Thus,a new direction and theoretical basis were provided for the utilization of municipal sludge by preparing GO.
2022, 40(7): 31-37.
doi: DOI:10.13205/j.hjgc.202207005
Abstract:
Fulvic acid is rich in nutrients.It is a plant regulator and can promote plant growth.In order to study the feasibility of soilification of phosphogypsum dealkalized red mud by applying fulvic acid,through the phosphogypsum dealkalized red mud test and the phosphogypsum-fulvic acid combined dealkalized red mud test,the physical and chemical properties of the dealkalized solution and the dealkalized residue were measured,and the pot experiment was carried out to verify its feasibility.The research results showed that:1) phosphogypsum dealkalization reduced the pH value of red mud from 11.08 to about 9.00,and the combined use of phosphogypsum and fulvic acid reduced the pH of red mud to about 8.50;2) the analysis results showed that the addition of fulvic acid promoted the formation of large-diameter agglomerates of red mud and increased the content of large-diameter aggregates and enhanced the stability of the aggregates;3) element analysis results of the dealkalized residue and dealkalized solution showed that the addition of fulvic acid increased the residual sodium ion content and sodium ions content on the red mud;4) pot experiment results showed that higher concentrations of heavy metal ions and sodium ions delayed the germination time of seeds by 4 days and reduced the germination rate of seeds by 8%.With effective dealkalizaton and stabilization of heavy metals in the red mud,the addition of fulvic acid would be beneficial to soil transformation of phosphogypsum dealkalized red mud.
Fulvic acid is rich in nutrients.It is a plant regulator and can promote plant growth.In order to study the feasibility of soilification of phosphogypsum dealkalized red mud by applying fulvic acid,through the phosphogypsum dealkalized red mud test and the phosphogypsum-fulvic acid combined dealkalized red mud test,the physical and chemical properties of the dealkalized solution and the dealkalized residue were measured,and the pot experiment was carried out to verify its feasibility.The research results showed that:1) phosphogypsum dealkalization reduced the pH value of red mud from 11.08 to about 9.00,and the combined use of phosphogypsum and fulvic acid reduced the pH of red mud to about 8.50;2) the analysis results showed that the addition of fulvic acid promoted the formation of large-diameter agglomerates of red mud and increased the content of large-diameter aggregates and enhanced the stability of the aggregates;3) element analysis results of the dealkalized residue and dealkalized solution showed that the addition of fulvic acid increased the residual sodium ion content and sodium ions content on the red mud;4) pot experiment results showed that higher concentrations of heavy metal ions and sodium ions delayed the germination time of seeds by 4 days and reduced the germination rate of seeds by 8%.With effective dealkalizaton and stabilization of heavy metals in the red mud,the addition of fulvic acid would be beneficial to soil transformation of phosphogypsum dealkalized red mud.
2022, 40(7): 38-44.
doi: DOI:10.13205/j.hjgc.202207006
Abstract:
Numerical simulation method was used to establish the fluid finite element analysis model of PHA accumulating by the mixed microbial culture (MMC) under aerobic dynamic discharge (ADD) and aerobic dynamic feeding (ADF) mode.The precipitation process was analyzed to discuss the generation principle and mechanism of physical selective pressure.The simulation obtained the distribution law of activated sludge with different sedimentation rate grades in the reactor with different residence times during the sedimentation process,and the distribution law of the sludge volume fraction along the vertical direction of the reactor.The results showed that the activated sludge in the ADD mode could form a relatively stable sedimentation difference stratified boundary during the sedimentation process.The sludge distribution volume fraction at a height of 0.6 m was about 0.75 within a residence time of 10~15 minutes,which provided a strong screening effect on the MMCs with strong PHA accumulating ability.The analysis process based on numerical simulation technology promoted the understanding of the mechanism of physical selective pressure screening,and could provide a theoretical basis for the optimization of parameters under ADD mode.
Numerical simulation method was used to establish the fluid finite element analysis model of PHA accumulating by the mixed microbial culture (MMC) under aerobic dynamic discharge (ADD) and aerobic dynamic feeding (ADF) mode.The precipitation process was analyzed to discuss the generation principle and mechanism of physical selective pressure.The simulation obtained the distribution law of activated sludge with different sedimentation rate grades in the reactor with different residence times during the sedimentation process,and the distribution law of the sludge volume fraction along the vertical direction of the reactor.The results showed that the activated sludge in the ADD mode could form a relatively stable sedimentation difference stratified boundary during the sedimentation process.The sludge distribution volume fraction at a height of 0.6 m was about 0.75 within a residence time of 10~15 minutes,which provided a strong screening effect on the MMCs with strong PHA accumulating ability.The analysis process based on numerical simulation technology promoted the understanding of the mechanism of physical selective pressure screening,and could provide a theoretical basis for the optimization of parameters under ADD mode.
2022, 40(7): 45-51.
doi: DOI:10.13205/j.hjgc.202207007
Abstract:
The reclaimed soil of the side slope and platform of the dumpsite in Jalai Nur Open-pit Coal Mine was selected as the research object.The soil's physical and chemical properties were determined,the soil microbial communities were analyzed,the correlation between soil microbial diversities and environmental factors was analyzed and compared with the non-reclaimed soil,and the feedback response of dumping site reclamation and soil microorganisms were also explored.The experimental results indicated that differences in physical and chemical properties of the reclaimed soil were mainly related to the soil depth.Compared with the soil of 10~20 cm,the physicochemical properties of 0~10 cm soil changed more greatly.Effects of soil bulk density,mechanical composition,and pH on the reclaimed soil were significantly higher than that of soil organic carbon,soil total nitrogen,and C/N ratio.The pH of the control soil was 8.87 and 8.76,much higher than the pH of the reclaimed soil.The microbial communities of the reclaimed soil were significantly different from the non-reclaimed soil.Reclamation was beneficial in improving the soil microbial communities with the soil organic carbon and total nitrogen content increasing.
The reclaimed soil of the side slope and platform of the dumpsite in Jalai Nur Open-pit Coal Mine was selected as the research object.The soil's physical and chemical properties were determined,the soil microbial communities were analyzed,the correlation between soil microbial diversities and environmental factors was analyzed and compared with the non-reclaimed soil,and the feedback response of dumping site reclamation and soil microorganisms were also explored.The experimental results indicated that differences in physical and chemical properties of the reclaimed soil were mainly related to the soil depth.Compared with the soil of 10~20 cm,the physicochemical properties of 0~10 cm soil changed more greatly.Effects of soil bulk density,mechanical composition,and pH on the reclaimed soil were significantly higher than that of soil organic carbon,soil total nitrogen,and C/N ratio.The pH of the control soil was 8.87 and 8.76,much higher than the pH of the reclaimed soil.The microbial communities of the reclaimed soil were significantly different from the non-reclaimed soil.Reclamation was beneficial in improving the soil microbial communities with the soil organic carbon and total nitrogen content increasing.
2022, 40(7): 52-60,115.
doi: DOI:10.13205/j.hjgc.202207008
Abstract:
As the skeleton part of the constructed wetland,the substrates play an important role in removing pollutants.Under the vertical flow dynamic conditions with different influent loads,the experiments selected loess balls,anthracite coal,and shale ceramsite for pollutant removal.For in-depth research about the adsorption activity and mechanism of three substrates,the mineral composition,and surface morphology were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM).The test results showed that due to its own deprotonation,loess balls could remove 80% of NH4+-N in the initial stage.Under high phosphorus load,the electrostatic interaction and atomic coordination reaction of loess balls improved their adsorption capacity for soluble reactive phosphorus (SRP) and particulate phosphorus (PP).In addition,the physical adsorption of loess balls had an average removal rate of 50% on COD,and improved the composition of dissolved organic matter (DOM) dominated by aromatics in water.The TP removal rate of anthracite could reach 80%,while the adsorption capacity of phosphorus for per unit matrix was 6.89 mg/kg.Due to the electrostatic adsorption of anthracite,the removal of SRP accounted for 44% of the TP removal.Shale ceramsite was derived from its own rich metal mineral composition,which was better in PP removal.The three substrates all showed certain adsorption activity on different pollutants in the continuous test,and "adsorption fatigue" of the pollutants also had significant differences in the continuous test.It was found that loess balls had potential application value of wetland substrates and helped to optimize the DOM components in water.
As the skeleton part of the constructed wetland,the substrates play an important role in removing pollutants.Under the vertical flow dynamic conditions with different influent loads,the experiments selected loess balls,anthracite coal,and shale ceramsite for pollutant removal.For in-depth research about the adsorption activity and mechanism of three substrates,the mineral composition,and surface morphology were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM).The test results showed that due to its own deprotonation,loess balls could remove 80% of NH4+-N in the initial stage.Under high phosphorus load,the electrostatic interaction and atomic coordination reaction of loess balls improved their adsorption capacity for soluble reactive phosphorus (SRP) and particulate phosphorus (PP).In addition,the physical adsorption of loess balls had an average removal rate of 50% on COD,and improved the composition of dissolved organic matter (DOM) dominated by aromatics in water.The TP removal rate of anthracite could reach 80%,while the adsorption capacity of phosphorus for per unit matrix was 6.89 mg/kg.Due to the electrostatic adsorption of anthracite,the removal of SRP accounted for 44% of the TP removal.Shale ceramsite was derived from its own rich metal mineral composition,which was better in PP removal.The three substrates all showed certain adsorption activity on different pollutants in the continuous test,and "adsorption fatigue" of the pollutants also had significant differences in the continuous test.It was found that loess balls had potential application value of wetland substrates and helped to optimize the DOM components in water.
2022, 40(7): 61-68.
doi: DOI:10.13205/j.hjgc.202207009
Abstract:
This research intended to investigate the influence of oil contamination on bacterial community,soil physico-chemical properties,and to isolate and identify oil-degrading bacteria.In this work,the microbial community structure of oil-contaminated soil and control soil in Baota,Wuqi,Jingbian,and Yanchang counties in northern Shaanxi were analyzed based on high-throughput sequencing technology,and the oil content,organic matter,nitrate nitrogen,ammonium nitrogen,available phosphorus,available potassium and pH were measured.With petroleum as the sole carbon source,oil-degrading bacteria were screened from oil-contaminated soils and identified based on 16S rDNA gene sequence.The contents of ammonium nitrogen,nitrate nitrogen,available phosphorus,and available potassium decreased by 0.57,6.63,4.34,8.91 mg/kg,respectively,and the content organic matter increased by 2~21 times.The richness and diversity of microorganisms were reduced after being contaminated with crude oil.In the oil-contaminated soil,Proteobacteria and Chloroflexi were the dominant phylum,and Mycobacterium was the genus with the highest abundance.Using petroleum as the only carbon source,8 strains of oil-degrading bacteria were isolated,among them,the 5-day oil degradation rates of OS33 and OS62-1 strains reached 80.51% and 81.60%.Finally,OS33 was identified as Dietzia sp.,and OS62-1 was Rhodococcus sp.After being contaminated with crude oil,the soil microbial community richness and diversity were decreased.8 oil-degrading bacteria were isolated and the highest 5-day oil degradation rate was 81.60%.This study further enriched the oil-degrading bacteria resource of northern Shaanxi.
This research intended to investigate the influence of oil contamination on bacterial community,soil physico-chemical properties,and to isolate and identify oil-degrading bacteria.In this work,the microbial community structure of oil-contaminated soil and control soil in Baota,Wuqi,Jingbian,and Yanchang counties in northern Shaanxi were analyzed based on high-throughput sequencing technology,and the oil content,organic matter,nitrate nitrogen,ammonium nitrogen,available phosphorus,available potassium and pH were measured.With petroleum as the sole carbon source,oil-degrading bacteria were screened from oil-contaminated soils and identified based on 16S rDNA gene sequence.The contents of ammonium nitrogen,nitrate nitrogen,available phosphorus,and available potassium decreased by 0.57,6.63,4.34,8.91 mg/kg,respectively,and the content organic matter increased by 2~21 times.The richness and diversity of microorganisms were reduced after being contaminated with crude oil.In the oil-contaminated soil,Proteobacteria and Chloroflexi were the dominant phylum,and Mycobacterium was the genus with the highest abundance.Using petroleum as the only carbon source,8 strains of oil-degrading bacteria were isolated,among them,the 5-day oil degradation rates of OS33 and OS62-1 strains reached 80.51% and 81.60%.Finally,OS33 was identified as Dietzia sp.,and OS62-1 was Rhodococcus sp.After being contaminated with crude oil,the soil microbial community richness and diversity were decreased.8 oil-degrading bacteria were isolated and the highest 5-day oil degradation rate was 81.60%.This study further enriched the oil-degrading bacteria resource of northern Shaanxi.
2022, 40(7): 69-75,152.
doi: DOI:10.13205/j.hjgc.202207010
Abstract:
This paper investigated temporal and spatial variations of ozone concentration in Lanzhou from 2018 to 2019 and further the effects of meteorological factors and the related pollutants on O3-8 h were discussed based on the dataset of observation from the meteorological stations and four air monitoring stations in Lanzhou.The results indicated that:1) The monthly concentration variation of O3-8 h showed a single peak trend in all stations in Lanzhou.The high value appeared from April to August and the low value appeared in winter.The diurnal distribution of O3 concentration showed a single peak pattern,and the highest concentration appeared at about 15:00.2) Relevant pollutants had a negative correlation with O3-8 h,which showed that the concentration of O3-8 h decreased with the increase of NO2,CO and PM2.5.3) High temperature and low humidity were conducive to the formation of O3 in Lanzhou,while the special topographic conditions led to the accumulation of ozone more easily under a certain wind speed.4) By establishing regression equations of multiple linear of related pollutants and meteorological factors,the effects of related pollutants and meteorological factors on O3-8 h concentration were studied.The results showed that the influence of meteorological factors on the concentration of O3 in Lanzhou was more important than that of the related pollutants under the current meteorological conditions and related pollutants emission status.
This paper investigated temporal and spatial variations of ozone concentration in Lanzhou from 2018 to 2019 and further the effects of meteorological factors and the related pollutants on O3-8 h were discussed based on the dataset of observation from the meteorological stations and four air monitoring stations in Lanzhou.The results indicated that:1) The monthly concentration variation of O3-8 h showed a single peak trend in all stations in Lanzhou.The high value appeared from April to August and the low value appeared in winter.The diurnal distribution of O3 concentration showed a single peak pattern,and the highest concentration appeared at about 15:00.2) Relevant pollutants had a negative correlation with O3-8 h,which showed that the concentration of O3-8 h decreased with the increase of NO2,CO and PM2.5.3) High temperature and low humidity were conducive to the formation of O3 in Lanzhou,while the special topographic conditions led to the accumulation of ozone more easily under a certain wind speed.4) By establishing regression equations of multiple linear of related pollutants and meteorological factors,the effects of related pollutants and meteorological factors on O3-8 h concentration were studied.The results showed that the influence of meteorological factors on the concentration of O3 in Lanzhou was more important than that of the related pollutants under the current meteorological conditions and related pollutants emission status.
2022, 40(7): 76-80,87.
doi: DOI:10.13205/j.hjgc.202207011
Abstract:
Co-incineration of aged refuse and domestic waste is one of the important ways to properly vacate the landfill and alleviate the shortage of urban land resources.The domestic waste incineration facility was used to carry out the test of co-incineration of aged refuse and domestic waste.According to the aged refuse proportion of 0,10%,20%,25%,and 30%,the impact of co-incineration on the emission of dioxin and other pollutants in the flue gas was analyzed.The results showed that the concentrations of particulate matter,SO2,HCl,NOx,and dioxin gradually increased with the increase of aged refuse co-incineration proportion,but they all met the standard limit.When mixed with 25% and 30% of aged refuse,the toxic equivalent concentration of PCDD/Fs was close to 0.1 ng-TEQ/m3and 0.13 ng-TEQ/m3 respectively.The proportion of mixed combustion increased from 0 to 20%,the generation of PCDD/Fs in the furnace increased,the concentration at the inlet of the treatment facility increased by 14%,and the removal rate of flue gas treatment process exceeded 99%.The De novo reaction was promoted,to some extent,by burning aged refuse.In order to ensure that the pollutants in the mixed combustion flue gas complied with the standard,factors such as the landfill age,nature and calorific value of the aged refuse,incineration and pollution prevention technology should be fully considered.
Co-incineration of aged refuse and domestic waste is one of the important ways to properly vacate the landfill and alleviate the shortage of urban land resources.The domestic waste incineration facility was used to carry out the test of co-incineration of aged refuse and domestic waste.According to the aged refuse proportion of 0,10%,20%,25%,and 30%,the impact of co-incineration on the emission of dioxin and other pollutants in the flue gas was analyzed.The results showed that the concentrations of particulate matter,SO2,HCl,NOx,and dioxin gradually increased with the increase of aged refuse co-incineration proportion,but they all met the standard limit.When mixed with 25% and 30% of aged refuse,the toxic equivalent concentration of PCDD/Fs was close to 0.1 ng-TEQ/m3and 0.13 ng-TEQ/m3 respectively.The proportion of mixed combustion increased from 0 to 20%,the generation of PCDD/Fs in the furnace increased,the concentration at the inlet of the treatment facility increased by 14%,and the removal rate of flue gas treatment process exceeded 99%.The De novo reaction was promoted,to some extent,by burning aged refuse.In order to ensure that the pollutants in the mixed combustion flue gas complied with the standard,factors such as the landfill age,nature and calorific value of the aged refuse,incineration and pollution prevention technology should be fully considered.
2022, 40(7): 81-87.
doi: DOI:10.13205/j.hjgc.202207012
Abstract:
Using the atomized spraying of humidification method to hydrate the calcium-based fly ash of the circulating fluidized bed (CFB),the performance of fly ash suspended desulfurization was experimentally studied under different conditions.The results showed that the hydrated fly ash had a good desulfurization capability at low temperature,which could be divided into two reaction stages,fast and slow phase,and enhanced the efficiency of total calcium utilization from an initial value of 41% to around 70%.The particle humidification effect and the reaction temperature were the main factors affecting the desulphurization ability.The atomization water-drop size closed to 50 μm and the staged spray-water method made a better humidification effect,and extended the duration of fast reaction to make the reaction more complete.The reaction temperature had two side functions of promotion and inhibition to the humidification and desulfurization,and the optimum temperature was around 80℃.The SO2 concentration was not remarkable to the desulphurization.After fly ash activated by atomized water spray,the microstructure on the particle surface was promoted with increased pores and cracks which would contribute to the gas-solid transfer and desulfurization reaction.
Using the atomized spraying of humidification method to hydrate the calcium-based fly ash of the circulating fluidized bed (CFB),the performance of fly ash suspended desulfurization was experimentally studied under different conditions.The results showed that the hydrated fly ash had a good desulfurization capability at low temperature,which could be divided into two reaction stages,fast and slow phase,and enhanced the efficiency of total calcium utilization from an initial value of 41% to around 70%.The particle humidification effect and the reaction temperature were the main factors affecting the desulphurization ability.The atomization water-drop size closed to 50 μm and the staged spray-water method made a better humidification effect,and extended the duration of fast reaction to make the reaction more complete.The reaction temperature had two side functions of promotion and inhibition to the humidification and desulfurization,and the optimum temperature was around 80℃.The SO2 concentration was not remarkable to the desulphurization.After fly ash activated by atomized water spray,the microstructure on the particle surface was promoted with increased pores and cracks which would contribute to the gas-solid transfer and desulfurization reaction.
2022, 40(7): 88-93,17.
doi: DOI:10.13205/j.hjgc.202207013
Abstract:
Due to its advantages of simple operation,low cost and high efficiency,inhibitors have been widely used in waste incinerators,and gradually become one of the important technologies to control dioxins.The effect of the inhibitor on fly ash characteristics and the concentration of PCDD/Fs in fly ash was studied by injecting the S-N-P-inhibitor into the heat recovery boiler of a typical circulating fluidized bed waste incinerator with high-precision feeding equipment.The results showed that the inhibitor decreased the content of PCDD/Fs in fly ash remarkably from 2.31 ng I-TEQ/g to 0.23 ng I-TEQ/g,with an inhibition efficiency of 90.0%,which was achieved through reducing the concentration of Cl2 in flue gas,increasing particle size and decreasing the specific surface area of fly ash.In addition,inhibitors also exhibit stabilization function on heavy metals,especially for Pb (with a stabilization rate of 49.02%).This research can provide technical support for the subsequent industrial application of the S-N-P-inhibitor.
Due to its advantages of simple operation,low cost and high efficiency,inhibitors have been widely used in waste incinerators,and gradually become one of the important technologies to control dioxins.The effect of the inhibitor on fly ash characteristics and the concentration of PCDD/Fs in fly ash was studied by injecting the S-N-P-inhibitor into the heat recovery boiler of a typical circulating fluidized bed waste incinerator with high-precision feeding equipment.The results showed that the inhibitor decreased the content of PCDD/Fs in fly ash remarkably from 2.31 ng I-TEQ/g to 0.23 ng I-TEQ/g,with an inhibition efficiency of 90.0%,which was achieved through reducing the concentration of Cl2 in flue gas,increasing particle size and decreasing the specific surface area of fly ash.In addition,inhibitors also exhibit stabilization function on heavy metals,especially for Pb (with a stabilization rate of 49.02%).This research can provide technical support for the subsequent industrial application of the S-N-P-inhibitor.
2022, 40(7): 94-100.
doi: DOI:10.13205/j.hjgc.202207014
Abstract:
To reduce the impact of landfills on residents and the environment when performing landfill operation,a solid waste landfill site in Jiangsu Province was taken as the research object to carry out a health risk assessment.Soil samples in the study area were collected and analysed to obtain the contents of heavy metals such as As,Ni,Cd,Zn,Pb,and Hg.Kriging interpolation,chemical mass balance morphological simulation,and health risk assessment models were applied respectively.The concentration spatial distribution,speciation,and regional health risk of heavy metals were studied.The results showed that the area was mainly polluted by solid waste landfills and over-fertilization of agricultural land.The contents of Cd and Zn were higher than the soil background values,and Hg content was close to the background value.15 types of metal forms of Cd and 21 metal forms of Zn were obtained by simulation.A health risk assessment was conducted on the obtained metal species,and it was concluded that Cd2+ and CdCO3 had carcinogenic risks,with total contribution rates of 38.4% and 31.9%,respectively.But Zn2S32- metal form had non-carcinogenic risk,and the total contribution rate was 91.66%.The carcinogenic risk of Cd2+ ranged from 10-6 to 10-4,and that's not ignorable.Therefore,the toxicity of heavy metal species to humans in the study area should be paid more attention to.
To reduce the impact of landfills on residents and the environment when performing landfill operation,a solid waste landfill site in Jiangsu Province was taken as the research object to carry out a health risk assessment.Soil samples in the study area were collected and analysed to obtain the contents of heavy metals such as As,Ni,Cd,Zn,Pb,and Hg.Kriging interpolation,chemical mass balance morphological simulation,and health risk assessment models were applied respectively.The concentration spatial distribution,speciation,and regional health risk of heavy metals were studied.The results showed that the area was mainly polluted by solid waste landfills and over-fertilization of agricultural land.The contents of Cd and Zn were higher than the soil background values,and Hg content was close to the background value.15 types of metal forms of Cd and 21 metal forms of Zn were obtained by simulation.A health risk assessment was conducted on the obtained metal species,and it was concluded that Cd2+ and CdCO3 had carcinogenic risks,with total contribution rates of 38.4% and 31.9%,respectively.But Zn2S32- metal form had non-carcinogenic risk,and the total contribution rate was 91.66%.The carcinogenic risk of Cd2+ ranged from 10-6 to 10-4,and that's not ignorable.Therefore,the toxicity of heavy metal species to humans in the study area should be paid more attention to.
2022, 40(7): 101-108.
doi: DOI:10.13205/j.hjgc.202207015
Abstract:
Biofilm is a common bacterial community in porous media,which can interact with suspended particles and affect the migration and deposition of particles.The Lattice Boltzmann-discrete element coupling method (LBM-DEM) was used to study the migration of suspended particles in porous media covered with biofilm.The presence of biofilms reduced the pore-throat size and the DLVO repulsive barrier,which helped enhance the deposition of suspended particles.The pressure difference between inlet and outlet was the main factor affecting the retention rate of particles.Under low-pressure difference between inlet and outlet,particles couldn't break through the exclusion barrier,and the flow force of high-pressure difference could increase the permeability by changing the deposition position of the particles.The change of ion concentration in the solution mainly affected the exclusion barrier.In the solution with high ion concentration,the particle retention rate had little response to the change of pressure difference.In the solution with low ion concentration,the particle retention was greatly affected by the inlet and outlet pressure difference.In addition,the effects of inflow velocity on the adhesion and rolling of suspended particles were also observed from a mesoscopic perspective.The angle between the initial deposition points of particles and the incoming flow direction decreased with the increase of particle velocity.
Biofilm is a common bacterial community in porous media,which can interact with suspended particles and affect the migration and deposition of particles.The Lattice Boltzmann-discrete element coupling method (LBM-DEM) was used to study the migration of suspended particles in porous media covered with biofilm.The presence of biofilms reduced the pore-throat size and the DLVO repulsive barrier,which helped enhance the deposition of suspended particles.The pressure difference between inlet and outlet was the main factor affecting the retention rate of particles.Under low-pressure difference between inlet and outlet,particles couldn't break through the exclusion barrier,and the flow force of high-pressure difference could increase the permeability by changing the deposition position of the particles.The change of ion concentration in the solution mainly affected the exclusion barrier.In the solution with high ion concentration,the particle retention rate had little response to the change of pressure difference.In the solution with low ion concentration,the particle retention was greatly affected by the inlet and outlet pressure difference.In addition,the effects of inflow velocity on the adhesion and rolling of suspended particles were also observed from a mesoscopic perspective.The angle between the initial deposition points of particles and the incoming flow direction decreased with the increase of particle velocity.
2022, 40(7): 109-115.
doi: DOI:10.13205/j.hjgc.202207016
Abstract:
In this paper,the effects of incinerator structure on combustion safety,temperature distribution,and flue properties were investigated with numerical simulation.The cold and hot states of a 650 t/d municipal solid waste incinerator were simulated.And the effects of secondary air temperature,secondary air layout,and rear arch angle on the combustion in the incinerator were explored.The simulation results showed that the overall average temperature in the furnace decreased by about 80℃,as the temperature of secondary air decreased from 180℃ to 25℃.The overall temperature decrease was beneficial to alleviate the problems of coking and high-temperature corrosion in the furnace.When the secondary air in the lower part of the front wall moved to the front arch,the secondary airflow formed an "air curtain" and pressed the combustible gas close to the grate,which may cause problems such as grate burning and tempering at the feed port.On this basis,when moving the front arch secondary air behind the front wall,the first flue gas had higher fullness and a more uniform temperature distribution.And the gas component concentration at the outlet of the first flue complied with China's national standard,GB 18485-2014,Domestic Waste Incineration Pollution Control Standard,making the incinerator suitable when burning high calorific value domestic waste.
In this paper,the effects of incinerator structure on combustion safety,temperature distribution,and flue properties were investigated with numerical simulation.The cold and hot states of a 650 t/d municipal solid waste incinerator were simulated.And the effects of secondary air temperature,secondary air layout,and rear arch angle on the combustion in the incinerator were explored.The simulation results showed that the overall average temperature in the furnace decreased by about 80℃,as the temperature of secondary air decreased from 180℃ to 25℃.The overall temperature decrease was beneficial to alleviate the problems of coking and high-temperature corrosion in the furnace.When the secondary air in the lower part of the front wall moved to the front arch,the secondary airflow formed an "air curtain" and pressed the combustible gas close to the grate,which may cause problems such as grate burning and tempering at the feed port.On this basis,when moving the front arch secondary air behind the front wall,the first flue gas had higher fullness and a more uniform temperature distribution.And the gas component concentration at the outlet of the first flue complied with China's national standard,GB 18485-2014,Domestic Waste Incineration Pollution Control Standard,making the incinerator suitable when burning high calorific value domestic waste.
2022, 40(7): 116-122,68.
doi: DOI:10.13205/j.hjgc.202207017
Abstract:
Aiming at the defects of high hardening degree and insufficient nutrients of sludge solidified soil,the solidified soil was improved by physically mixing with mushroom residue and magnesium sulfate for landscaping.The effects of mushroom residue content and particle size on improvement of sludge solidified soil were studied by analysing the physical properties and nutrient content of mushroom residue improved soil,ryegrass seed germination test,and pot experiment.The results showed that the sludge solidified soil mixed with 40 g/kg with a particle size of 5~10 mm bacterial residue and 0.2 g/kg magnesium sulfate had the best effect.The plant height of ryegrass increased by 32.3% and the dry weight increased by 126.7%.Mushroom residue had loose and porous characteristics,which could improve soil pore structure,reduce soil bulk density and improve soil water retention;magnesium sulfate supplemented available magnesium and available sulfur in soil;and the nutrients of bacterial residue improved the content of soil organic matter,hydrolyzable nitrogen,available phosphorus,available potassium and other nutrients,and improved the ability of soil fertilizer retention.Bacterial residue can be used as a soil conditioner to realize the low-cost improvement and utilization of sludge solidified soil.
Aiming at the defects of high hardening degree and insufficient nutrients of sludge solidified soil,the solidified soil was improved by physically mixing with mushroom residue and magnesium sulfate for landscaping.The effects of mushroom residue content and particle size on improvement of sludge solidified soil were studied by analysing the physical properties and nutrient content of mushroom residue improved soil,ryegrass seed germination test,and pot experiment.The results showed that the sludge solidified soil mixed with 40 g/kg with a particle size of 5~10 mm bacterial residue and 0.2 g/kg magnesium sulfate had the best effect.The plant height of ryegrass increased by 32.3% and the dry weight increased by 126.7%.Mushroom residue had loose and porous characteristics,which could improve soil pore structure,reduce soil bulk density and improve soil water retention;magnesium sulfate supplemented available magnesium and available sulfur in soil;and the nutrients of bacterial residue improved the content of soil organic matter,hydrolyzable nitrogen,available phosphorus,available potassium and other nutrients,and improved the ability of soil fertilizer retention.Bacterial residue can be used as a soil conditioner to realize the low-cost improvement and utilization of sludge solidified soil.
2022, 40(7): 123-131.
doi: DOI:10.13205/j.hjgc.202207018
Abstract:
Cadium in soil has the characteristics of difficult degradation,easy migration accumulation,and is easily to cause damage to the soil environment and threatens food security.Five kinds of new stabilization materials were prepared by loading poly-aluminum ferric chloride on attapulgite.Scanning electron microscope (SEM) characterization,stabilization experiment and corn pot experiment were conducted to evaluate the stabilization effect and environmental risk of Cd in contaminated soil.The results showed that the concentrations of diethylenetriamine pentaacetic acid extracted Cd (DTPA),and toxic characteristic leached Cd (TCLP) were significantly reduced after the application of attapulgite modified with poly-aluminum ferric chloride.In the soil treated with attapulgite modified with a 25% mass ratio of poly-aluminum ferric chloride,the two bioavailable Cd concentrations decreased by 21.51% and 29.3%,respectively.The application of modified attapulgite promoted the growth of corn,and the treatment effect of modified attapulgite with 25% poly-aluminum ferric chloride was the best.In comparison to the control group,the shoot length of corn increased by 52.2%,and the fresh biomass of shoot and root increased by 75.1% and 64.5% respectively.Meanwhile,the dry biomass of shoot and root increased by 80.5% and 79.7% compared with CK.Furthermore,the content of Cd accumulated in the shoot and root of corn decreased by 43.4% and 24.7%,respectively.Attapulgite modified by poly-aluminum ferric chloride has larger specific surface area,higher ion exchange capacity and surface complexation properties,which greatly reduced the bioavailability of heavy metals in soil,so it could be used in stabilization remediation of Cd contaminated farmland soils.
Cadium in soil has the characteristics of difficult degradation,easy migration accumulation,and is easily to cause damage to the soil environment and threatens food security.Five kinds of new stabilization materials were prepared by loading poly-aluminum ferric chloride on attapulgite.Scanning electron microscope (SEM) characterization,stabilization experiment and corn pot experiment were conducted to evaluate the stabilization effect and environmental risk of Cd in contaminated soil.The results showed that the concentrations of diethylenetriamine pentaacetic acid extracted Cd (DTPA),and toxic characteristic leached Cd (TCLP) were significantly reduced after the application of attapulgite modified with poly-aluminum ferric chloride.In the soil treated with attapulgite modified with a 25% mass ratio of poly-aluminum ferric chloride,the two bioavailable Cd concentrations decreased by 21.51% and 29.3%,respectively.The application of modified attapulgite promoted the growth of corn,and the treatment effect of modified attapulgite with 25% poly-aluminum ferric chloride was the best.In comparison to the control group,the shoot length of corn increased by 52.2%,and the fresh biomass of shoot and root increased by 75.1% and 64.5% respectively.Meanwhile,the dry biomass of shoot and root increased by 80.5% and 79.7% compared with CK.Furthermore,the content of Cd accumulated in the shoot and root of corn decreased by 43.4% and 24.7%,respectively.Attapulgite modified by poly-aluminum ferric chloride has larger specific surface area,higher ion exchange capacity and surface complexation properties,which greatly reduced the bioavailability of heavy metals in soil,so it could be used in stabilization remediation of Cd contaminated farmland soils.
2022, 40(7): 132-138,164.
doi: DOI:10.13205/j.hjgc.202207019
Abstract:
To reveal the key factors that limit the remediation effectiveness of heavily chromium contaminated soil,the desorption kinetics,and insoluble Cr (Ⅵ) reduction experiments were carried out in this study.The results showed that leaching with citric acid could significantly reduce the concentration of insoluble Cr (Ⅵ) in soil samples at room temperature,and increasing the leaching temperature to 90℃ could further decrease the concentration of insoluble Cr (Ⅵ).The lower the concentration of insoluble Cr (Ⅵ) in the soil after leaching,the better the remediation effectiveness.For the soil samples used in this study,the concentration of Cr (Ⅵ) decreased from (1813.2±59.8) mg/kg to (99.1±8.8) mg/kg by high-temperature flushing with citric acid and high-temperature reduction with ferrous sulfate.In addition,the reduction of insoluble Cr (Ⅵ) by citric acid in the leaching experiment could be ignored and the residual citric acid in the soil sample had no significant effect on the detection results of Cr (Ⅵ) in soil.This study proved that the reduction effectiveness of insoluble Cr (Ⅵ) was the key limiting factor for the remediation of heavy chromium-contaminated soil,and provided a reference for the research and development of remediation technology for chromium contaminated soil.
To reveal the key factors that limit the remediation effectiveness of heavily chromium contaminated soil,the desorption kinetics,and insoluble Cr (Ⅵ) reduction experiments were carried out in this study.The results showed that leaching with citric acid could significantly reduce the concentration of insoluble Cr (Ⅵ) in soil samples at room temperature,and increasing the leaching temperature to 90℃ could further decrease the concentration of insoluble Cr (Ⅵ).The lower the concentration of insoluble Cr (Ⅵ) in the soil after leaching,the better the remediation effectiveness.For the soil samples used in this study,the concentration of Cr (Ⅵ) decreased from (1813.2±59.8) mg/kg to (99.1±8.8) mg/kg by high-temperature flushing with citric acid and high-temperature reduction with ferrous sulfate.In addition,the reduction of insoluble Cr (Ⅵ) by citric acid in the leaching experiment could be ignored and the residual citric acid in the soil sample had no significant effect on the detection results of Cr (Ⅵ) in soil.This study proved that the reduction effectiveness of insoluble Cr (Ⅵ) was the key limiting factor for the remediation of heavy chromium-contaminated soil,and provided a reference for the research and development of remediation technology for chromium contaminated soil.
2022, 40(7): 139-145.
doi: DOI:10.13205/j.hjgc.202207020
Abstract:
Municipal sludge and corn straw mixtures from three cities,Tianjin,Zhaotong,Taiyuan in China were subjected to thermophilic anaerobic digestion (55℃) with domesticated secondary sedimentation tank sewage as the inoculum.The changes in pH,single-day and cumulative biogas production,and methane production under different systems with digestion time were investigated.The results indicated that anaerobic digestion of sludge-only exhibited no acidification,and its pH value was higher than that of the trials fed with corn straw.The maximum single-day biogas production of the sludge anaerobic digestion system appeared on the first or second day.With the addition of corn straw,the maximum single-day biogas production was delayed.The cumulative biogas production of the Tianjin sludge-only group reached 2004 mL,which was higher than the other two groups.The removal rates of VS under all fermentation systems were higher than 40%.As the digestion process stabilized,the methane content in biogas was maintained at 70%~85%(volume ratio).The specific methane production of Tianjin sludge-only reached 141.01 mL/g-VS.Gompertz model revealed that the sludge-only groups did not fit with the"S"curve,and the lag phase was very short.When the sludge:corn straw was 3:1 or 2:1,both the specific methane production,methane production rate,and lag phase had certain advantages.
Municipal sludge and corn straw mixtures from three cities,Tianjin,Zhaotong,Taiyuan in China were subjected to thermophilic anaerobic digestion (55℃) with domesticated secondary sedimentation tank sewage as the inoculum.The changes in pH,single-day and cumulative biogas production,and methane production under different systems with digestion time were investigated.The results indicated that anaerobic digestion of sludge-only exhibited no acidification,and its pH value was higher than that of the trials fed with corn straw.The maximum single-day biogas production of the sludge anaerobic digestion system appeared on the first or second day.With the addition of corn straw,the maximum single-day biogas production was delayed.The cumulative biogas production of the Tianjin sludge-only group reached 2004 mL,which was higher than the other two groups.The removal rates of VS under all fermentation systems were higher than 40%.As the digestion process stabilized,the methane content in biogas was maintained at 70%~85%(volume ratio).The specific methane production of Tianjin sludge-only reached 141.01 mL/g-VS.Gompertz model revealed that the sludge-only groups did not fit with the"S"curve,and the lag phase was very short.When the sludge:corn straw was 3:1 or 2:1,both the specific methane production,methane production rate,and lag phase had certain advantages.
2022, 40(7): 146-152.
doi: DOI:10.13205/j.hjgc.202207021
Abstract:
To solve the problem of wide distribution,great difference and variation in treating rural domestic sewage,a novel basalt fiber (BF) was explored as a biological carrier to build an integrated Johkasou.The effect was evaluated by multi-factor orthogonal test and actual wastewater treatment.The microbial flora of aerobic and anoxic reaction tanks was analyzed to explain the performance of Johkasou.The results showed that when DO in the aerobic tank was 3 mg/L,HRT was 8 h,pH was 7~7.5,the Johkasou exhibited the best removal effect on COD,NH4+-N,TN and other pollutants,and when DO of the aerobic tank was more than 2 mg/L,the Johkasou possessed a certain impact resistance to COD load and C/N fluctuation.Using actual domestic sewage to evaluate the operation effect of the Johkasou,the removal rates of COD,NH4+-N,and TN were as high as 89.60%,87.03%,and 82.22%,respectively.The denitrification performance was better than that of the traditional granular packing Johkasou. Ferruginibacter,Candidatus_Saccharimonas,and Terrimonas were the dominant bacteria in Johkasou,which could decompose macromolecular organic matters in sewage.Terrimonas,Acidovorax,and Thermomonas could play different roles in promoting nitrogen cycle.
To solve the problem of wide distribution,great difference and variation in treating rural domestic sewage,a novel basalt fiber (BF) was explored as a biological carrier to build an integrated Johkasou.The effect was evaluated by multi-factor orthogonal test and actual wastewater treatment.The microbial flora of aerobic and anoxic reaction tanks was analyzed to explain the performance of Johkasou.The results showed that when DO in the aerobic tank was 3 mg/L,HRT was 8 h,pH was 7~7.5,the Johkasou exhibited the best removal effect on COD,NH4+-N,TN and other pollutants,and when DO of the aerobic tank was more than 2 mg/L,the Johkasou possessed a certain impact resistance to COD load and C/N fluctuation.Using actual domestic sewage to evaluate the operation effect of the Johkasou,the removal rates of COD,NH4+-N,and TN were as high as 89.60%,87.03%,and 82.22%,respectively.The denitrification performance was better than that of the traditional granular packing Johkasou. Ferruginibacter,Candidatus_Saccharimonas,and Terrimonas were the dominant bacteria in Johkasou,which could decompose macromolecular organic matters in sewage.Terrimonas,Acidovorax,and Thermomonas could play different roles in promoting nitrogen cycle.
2022, 40(7): 153-158.
doi: DOI:10.13205/j.hjgc.202207022
Abstract:
Given the serious ecological damage caused by global marine garbage pollution,a sea garbage detection algorithm based on improved fast R-CNN and a method of whether the targets in the front and back frames of the video are the same target were proposed.The improved fast R-CNN algorithm improved the detection accuracy of small targets by replacing the commonly used VGG16 feature extraction network with ResNet101network and integrating it into the feature pyramid;the method to judge whether the two frames before and after the video were the same target,was to determine whether they were the same target by comparing the area,coincidence and color difference of them.The experimental results on the field shooting data showed that compared with the traditional fast R-CNN,the map value of the improved fast R-CNN in this paper was increased by 4.9%,the convergence speed of the loss curve was faster,and the detection effect in the actual detection was better;the proposed method for judging whether the two frames are the same object had a peak precision of 100% and an average accuracy of 93% in nine videos.The proposed method mainly included the following advantages:1) the improved fast R-CNN had higher accuracy in the detection of small target garbage on the sea surface;2) the algorithm code complexity of judging whether the target of the first and second frames in the video is the same target is small,making it convenient to change the judgment threshold according to the actual situation.
Given the serious ecological damage caused by global marine garbage pollution,a sea garbage detection algorithm based on improved fast R-CNN and a method of whether the targets in the front and back frames of the video are the same target were proposed.The improved fast R-CNN algorithm improved the detection accuracy of small targets by replacing the commonly used VGG16 feature extraction network with ResNet101network and integrating it into the feature pyramid;the method to judge whether the two frames before and after the video were the same target,was to determine whether they were the same target by comparing the area,coincidence and color difference of them.The experimental results on the field shooting data showed that compared with the traditional fast R-CNN,the map value of the improved fast R-CNN in this paper was increased by 4.9%,the convergence speed of the loss curve was faster,and the detection effect in the actual detection was better;the proposed method for judging whether the two frames are the same object had a peak precision of 100% and an average accuracy of 93% in nine videos.The proposed method mainly included the following advantages:1) the improved fast R-CNN had higher accuracy in the detection of small target garbage on the sea surface;2) the algorithm code complexity of judging whether the target of the first and second frames in the video is the same target is small,making it convenient to change the judgment threshold according to the actual situation.
2022, 40(7): 159-164,185.
doi: DOI:10.13205/j.hjgc.202207023
Abstract:
Based on solid phase extraction (SPE) and gas chromatography/mass spectrometry (GC-MS),the study herein established a quantitative analysis method for trace benzo (a) pyrene (BaP) in coking wastewater.The BaP-containing water samples were enriched and purified by SPE after being modified by methanol,then eluted by dichloromethane,concentrated by nitrogen blowing,and quantified by GC-MS after constant volume of dichloromethane or acetonitrile.The results showed that,after the optimization of sample pretreatment and under the analysis conditions,the linear correlation coefficient (R2) of BaP standard curve was greater than 0.99,the recovery rate was in the range of 79.6%~85.5%,the detection limit and quantitative limit were 4.33 ng/L and 14.45 ng/L,respectively.This method was then applied to the determination of BaP in the secondary effluent of a coking plant in Inner Mongolia.The recoveries of spiked BaP samples were in the range of 83.3%~89.3%,indicating that this method presented high sensitivity and good selectivity.It is suitable for the quantitative determination of trace BaP in coking wastewater.
Based on solid phase extraction (SPE) and gas chromatography/mass spectrometry (GC-MS),the study herein established a quantitative analysis method for trace benzo (a) pyrene (BaP) in coking wastewater.The BaP-containing water samples were enriched and purified by SPE after being modified by methanol,then eluted by dichloromethane,concentrated by nitrogen blowing,and quantified by GC-MS after constant volume of dichloromethane or acetonitrile.The results showed that,after the optimization of sample pretreatment and under the analysis conditions,the linear correlation coefficient (R2) of BaP standard curve was greater than 0.99,the recovery rate was in the range of 79.6%~85.5%,the detection limit and quantitative limit were 4.33 ng/L and 14.45 ng/L,respectively.This method was then applied to the determination of BaP in the secondary effluent of a coking plant in Inner Mongolia.The recoveries of spiked BaP samples were in the range of 83.3%~89.3%,indicating that this method presented high sensitivity and good selectivity.It is suitable for the quantitative determination of trace BaP in coking wastewater.
2022, 40(7): 165-171.
doi: DOI:10.13205/j.hjgc.202207024
Abstract:
In this paper,the effect of the molar ratios of ruthenium (Ru)-iridium (Ir) on the microstructure,chemical properties,electrochemical performance,and denitrification performance of high ammonia-chloride wastewater were investigated.The results illustrated that Ru-Ir solid solution was a rutile crystal with uniform grain distribution and tight connection.The electrochemical performances of the electrodes were tested by electrochemical techniques.And the electrochemical performance of the Ru-Ir electrode first increased and then decreased with the increase of the molar ratio of Ir.The electrochemical properties of Ru2/3Ir1/3O2 electrodes were the best when the molar ratio of Ru-Ir was 2:1.The chlorine evolution potential,corrosion current density,and conductivity of Ru2/3Ir1/3O2 electrode were 0.998,0.755,and 1.816 times those of RuO2,respectively.In the removal process of ammonia-nitrogen in high chloride ammonia-nitrogen simulated wastewater,the electrode with the best removal effect of ammonia-nitrogen was Ru2/3Ir1/3O2 electrode,and when the current was 0.5 A,the ammonia-nitrogen removal rate could reach 75.2% in 50 minutes.This paper proved that electrocatalytic technology could effectively treat high chloride ammonia-nitrogen wastewater.
In this paper,the effect of the molar ratios of ruthenium (Ru)-iridium (Ir) on the microstructure,chemical properties,electrochemical performance,and denitrification performance of high ammonia-chloride wastewater were investigated.The results illustrated that Ru-Ir solid solution was a rutile crystal with uniform grain distribution and tight connection.The electrochemical performances of the electrodes were tested by electrochemical techniques.And the electrochemical performance of the Ru-Ir electrode first increased and then decreased with the increase of the molar ratio of Ir.The electrochemical properties of Ru2/3Ir1/3O2 electrodes were the best when the molar ratio of Ru-Ir was 2:1.The chlorine evolution potential,corrosion current density,and conductivity of Ru2/3Ir1/3O2 electrode were 0.998,0.755,and 1.816 times those of RuO2,respectively.In the removal process of ammonia-nitrogen in high chloride ammonia-nitrogen simulated wastewater,the electrode with the best removal effect of ammonia-nitrogen was Ru2/3Ir1/3O2 electrode,and when the current was 0.5 A,the ammonia-nitrogen removal rate could reach 75.2% in 50 minutes.This paper proved that electrocatalytic technology could effectively treat high chloride ammonia-nitrogen wastewater.
2022, 40(7): 172-178.
doi: DOI:10.13205/j.hjgc.202207025
Abstract:
This study established a method to identify the source of ambient VOCs in residential areas to address the environmental NIMBY problem in an economic development zone in the Guangdong-Hong Kong-Macao Greater Bay Area.We carried out general survey and emission test on key polluting enterprises frequently complained in the industrial zone,and created a database of pollution source emission characteristics (fingerprints) and used pollution characteristics correlation analysis to track back the likely sources.A case study based on a field census and VOC emission on source-receptor sites was conducted to validate the method.We employed SPIMS (online VOC mass spectrometer) to obtain the speciate characteristics of VOC emissions from local industrial sources and VOCs fingerprint database.Through off-line sampling of sensitive points and navigation monitoring,the matching characteristic data spectrum was established.Combined with the correlation analysis of pollution characteristics,the corresponding pollution source emission characteristic (fingerprint) database and the rapid identification model of pollution sources were constructed.Six important enterprises with high potential VOC emissions were identified in the case study,including two plastic product enterprises,one spice manufacturing enterprise,and three electronic product manufacturing enterprises.By comparing on-site observed VOC species detected inside the enterprises to VOCs species from ambient air samples in residential areas,the key enterprises that had an impact on the residential area were identified as mainly methane,n-butane,isopentane,acetone,butanone,ethyl acetate,m-and p-xylene.The case study showed that the strategy could provide solid scientific and technological support for daily industrial source control and fast response to pollution concerns.
This study established a method to identify the source of ambient VOCs in residential areas to address the environmental NIMBY problem in an economic development zone in the Guangdong-Hong Kong-Macao Greater Bay Area.We carried out general survey and emission test on key polluting enterprises frequently complained in the industrial zone,and created a database of pollution source emission characteristics (fingerprints) and used pollution characteristics correlation analysis to track back the likely sources.A case study based on a field census and VOC emission on source-receptor sites was conducted to validate the method.We employed SPIMS (online VOC mass spectrometer) to obtain the speciate characteristics of VOC emissions from local industrial sources and VOCs fingerprint database.Through off-line sampling of sensitive points and navigation monitoring,the matching characteristic data spectrum was established.Combined with the correlation analysis of pollution characteristics,the corresponding pollution source emission characteristic (fingerprint) database and the rapid identification model of pollution sources were constructed.Six important enterprises with high potential VOC emissions were identified in the case study,including two plastic product enterprises,one spice manufacturing enterprise,and three electronic product manufacturing enterprises.By comparing on-site observed VOC species detected inside the enterprises to VOCs species from ambient air samples in residential areas,the key enterprises that had an impact on the residential area were identified as mainly methane,n-butane,isopentane,acetone,butanone,ethyl acetate,m-and p-xylene.The case study showed that the strategy could provide solid scientific and technological support for daily industrial source control and fast response to pollution concerns.
2022, 40(7): 179-185.
doi: DOI:10.13205/j.hjgc.202207026
Abstract:
As an iron and steel production intensive city,Tangshan's crude steel output reached 144 million tons in 2020,and the comprehensive energy consumption of industries above designated size in the city was 99.74 million tons of standard coal.In 2018,Tangshan's industrial sulfur dioxide and nitrogen oxide emissions were about 69000 tons and 158000 tons.Under the dual challenges of sustainable industrial transformation and development and urban inclusion,HBIS group took advantage of the opportunity of iron and steel industrial structure adjustment in Hebei Province to optimize its industrial layout and build Tangsteel New District with the design concept of green factory with high efficiency,energy saving,low carbon and environmental protection.In particular,a series of green manufacturing technologies were implemented in the aspects of energy efficiency improvement,ultra-low emission in the whole process,resource utilization of by-products and efficient utilization of water resources,which provides a reference for domestic iron and steel enterprises to apply green manufacturing technology.
As an iron and steel production intensive city,Tangshan's crude steel output reached 144 million tons in 2020,and the comprehensive energy consumption of industries above designated size in the city was 99.74 million tons of standard coal.In 2018,Tangshan's industrial sulfur dioxide and nitrogen oxide emissions were about 69000 tons and 158000 tons.Under the dual challenges of sustainable industrial transformation and development and urban inclusion,HBIS group took advantage of the opportunity of iron and steel industrial structure adjustment in Hebei Province to optimize its industrial layout and build Tangsteel New District with the design concept of green factory with high efficiency,energy saving,low carbon and environmental protection.In particular,a series of green manufacturing technologies were implemented in the aspects of energy efficiency improvement,ultra-low emission in the whole process,resource utilization of by-products and efficient utilization of water resources,which provides a reference for domestic iron and steel enterprises to apply green manufacturing technology.
2022, 40(7): 186-192.
doi: DOI:10.13205/j.hjgc.202207027
Abstract:
The product of decoration waste of newly-built houses in Beijing Daxing Old Palace assembly construction project was estimated by the area conversion algorithm,the renovation cycle was analyzed by Monte Carlo simulation,and the output of newly-built residential building renovation waste every year was estimated,and the suggestions of decoration waste management in Beijing was put forward by analysing the characteristics of inert decoration waste pollutants.The specific results was as follows:the amount of newly decorated waste in residential areas was 164.08 t,the relative error was about 9.58%.Using Oracle Crystal Ball to conduct Monte Carlo simulation analysis,the results showed that the renovation cycle of residential buildings was 7 to 10 years in Beijing by 20000 times simulations;through future refurbishment estimates,the formula of refurbished decoration area is UA=[Ay-15,r …Ay-4,r]×t;the heavy metals of As,Pb,Cd,Cr and Zn in the inert decoration waste exceeded the environmental background value of Beijing.To avoid environmental pollution caused by direct stacking or landfilling,the control of source decoration activities must be strengthened,the special disposal plan for the toxic and harmful components must be proposed,and harmless monitoring and management for decoration waste must be established.The results can provide references for the development of specialized treatment plans for different types of decoration waste.
The product of decoration waste of newly-built houses in Beijing Daxing Old Palace assembly construction project was estimated by the area conversion algorithm,the renovation cycle was analyzed by Monte Carlo simulation,and the output of newly-built residential building renovation waste every year was estimated,and the suggestions of decoration waste management in Beijing was put forward by analysing the characteristics of inert decoration waste pollutants.The specific results was as follows:the amount of newly decorated waste in residential areas was 164.08 t,the relative error was about 9.58%.Using Oracle Crystal Ball to conduct Monte Carlo simulation analysis,the results showed that the renovation cycle of residential buildings was 7 to 10 years in Beijing by 20000 times simulations;through future refurbishment estimates,the formula of refurbished decoration area is UA=[Ay-15,r …Ay-4,r]×t;the heavy metals of As,Pb,Cd,Cr and Zn in the inert decoration waste exceeded the environmental background value of Beijing.To avoid environmental pollution caused by direct stacking or landfilling,the control of source decoration activities must be strengthened,the special disposal plan for the toxic and harmful components must be proposed,and harmless monitoring and management for decoration waste must be established.The results can provide references for the development of specialized treatment plans for different types of decoration waste.
A NOVEL MODE OF NEAR ZERO LIQUID DISCHARGE FOR HIGH-TECH ZONES:FIVE-LEVEL-TREATMENT&FIVE-LEVEL-REUSE
2022, 40(7): 193-199.
doi: DOI:10.13205/j.hjgc.202207028
Abstract:
Near zero liquid discharge (NZLD) of high-tech zone (HTZ) is an effective way to improve water resources utilization efficiency and promote industrial restructuring and upgrading.However,current NZLD research mainly focused on the development and improvement of unit treatment technology,and neglected the systematic NZLD scheme for an integrated zone,which restricted the practice and popularization of NZLD.To this end,taking the whole HTZ as the research object,on the basis of systematic analysis of water use and drainage characteristics of typical industries,a five-level-treatment&five-level-reuse NZLD mode was proposed,which was the coupling of in-situ treatment-reuse based on water quality,enterprise wastewater treatment-comprehensive reuse,zone wastewater plant treatment-municipal use,ecological treatment-ecological water supplement,regeneration treatment-industrial reuse.Key problems of the mode were also analyzed,such as the construction of an intelligent decision system,the development of water treatment technology,and the establishment of an operation guarantee system.The novel mode would provide a feasible and effective way for NZLD of high-tech zones.
Near zero liquid discharge (NZLD) of high-tech zone (HTZ) is an effective way to improve water resources utilization efficiency and promote industrial restructuring and upgrading.However,current NZLD research mainly focused on the development and improvement of unit treatment technology,and neglected the systematic NZLD scheme for an integrated zone,which restricted the practice and popularization of NZLD.To this end,taking the whole HTZ as the research object,on the basis of systematic analysis of water use and drainage characteristics of typical industries,a five-level-treatment&five-level-reuse NZLD mode was proposed,which was the coupling of in-situ treatment-reuse based on water quality,enterprise wastewater treatment-comprehensive reuse,zone wastewater plant treatment-municipal use,ecological treatment-ecological water supplement,regeneration treatment-industrial reuse.Key problems of the mode were also analyzed,such as the construction of an intelligent decision system,the development of water treatment technology,and the establishment of an operation guarantee system.The novel mode would provide a feasible and effective way for NZLD of high-tech zones.
2022, 40(7): 200-205,8.
doi: DOI:10.13205/j.hjgc.202207029
Abstract:
Arsenic is a persistent and toxic carcinogen pollutant.In recent years,arsenic pollution incidents occur frequently in China.It is of great significance to establish human health water quality criteria for arsenic in China.Taking the Tieling Section of Liaohe River as the research object,the content of arsenic in water samples and fish samples of different nutritional levels were collected and analyzed.Combined with literature research,the toxicity parameters of arsenic pollutants and the exposure parameters of some people related to drinking water in the Tieling Section of Liaohe River were determined.Through the online questionnaire survey,it was calculated that the per capita fish intake of the second,third,and fourth nutritional levels of local residents was 0.0268,0.0323,and 0.0027 kg/d.Then it was derived that the second,third,and fourth trophic national bioaccumulation factors were 8.256,9.281,and 10.197 L/kg of local representative fishes.According to the above parameters,it was calculated that the reference value of human health water quality criteria of arsenic in the Tieling Section of Liaohe River was 1.976×10-5 mg/L,which provided a reference for the formulation of water quality standards in Liaohe River Basin,and a basis for scientific and effective pollution control and protection of human health.
Arsenic is a persistent and toxic carcinogen pollutant.In recent years,arsenic pollution incidents occur frequently in China.It is of great significance to establish human health water quality criteria for arsenic in China.Taking the Tieling Section of Liaohe River as the research object,the content of arsenic in water samples and fish samples of different nutritional levels were collected and analyzed.Combined with literature research,the toxicity parameters of arsenic pollutants and the exposure parameters of some people related to drinking water in the Tieling Section of Liaohe River were determined.Through the online questionnaire survey,it was calculated that the per capita fish intake of the second,third,and fourth nutritional levels of local residents was 0.0268,0.0323,and 0.0027 kg/d.Then it was derived that the second,third,and fourth trophic national bioaccumulation factors were 8.256,9.281,and 10.197 L/kg of local representative fishes.According to the above parameters,it was calculated that the reference value of human health water quality criteria of arsenic in the Tieling Section of Liaohe River was 1.976×10-5 mg/L,which provided a reference for the formulation of water quality standards in Liaohe River Basin,and a basis for scientific and effective pollution control and protection of human health.
2022, 40(7): 206-221,178.
doi: DOI:10.13205/j.hjgc.202207030
Abstract:
The biofilm formation on materials has complicated effects on the environment and anthropogenic activities,but the systematic elaboration on the interfacial interaction between environmental functional materials and microorganisms has not been given yet.This paper introduces the formation process of biofilm on the material surface,and analyzes the regulation mechanism of the physicochemical properties such as surface hydrophobicity,morphological characteristics,surface charge,magnetism,material release and electron transfer on biofilm formation.In addition,the effects of materials on microbial community structure and metabolic function of biofilm are reviewed,and the potential mechanism and application of different environmental functional materials coupling with biofilm in the fields of water treatment,biological waste gas treatment and soil ecological restoration are also investigated.Finally,this study points out the future research direction of the interaction between materials and microorganisms.This review aims to provide theoretical and technical support for the formation and control of surface biofilm of environmental functional materials,and give full play to their synergistic effects and direct material synthesis.
The biofilm formation on materials has complicated effects on the environment and anthropogenic activities,but the systematic elaboration on the interfacial interaction between environmental functional materials and microorganisms has not been given yet.This paper introduces the formation process of biofilm on the material surface,and analyzes the regulation mechanism of the physicochemical properties such as surface hydrophobicity,morphological characteristics,surface charge,magnetism,material release and electron transfer on biofilm formation.In addition,the effects of materials on microbial community structure and metabolic function of biofilm are reviewed,and the potential mechanism and application of different environmental functional materials coupling with biofilm in the fields of water treatment,biological waste gas treatment and soil ecological restoration are also investigated.Finally,this study points out the future research direction of the interaction between materials and microorganisms.This review aims to provide theoretical and technical support for the formation and control of surface biofilm of environmental functional materials,and give full play to their synergistic effects and direct material synthesis.
2022, 40(7): 222-231,247.
doi: DOI:10.13205/j.hjgc.202207031
Abstract:
Dioxins can cause persistent organic pollution and harm to the environment.Since the discovery of dioxins in the flue gas of municipal solid waste (MSW) incineration in the 1980s,many basic and applied researches have been carried out on the control of dioxins emission.Chemical inhibitors,which can inhibit the formation of dioxins during the incineration process,have been the research hotspot in this field.In this paper,the formation mechanism of dioxins and the current control strategies were introduced,and the advantages of using inhibitors were put forward.The types and mechanisms of dioxin inhibitors were reviewed,including the commonly used nitrogen/sulfur-based inhibitors,alkaline inhibitors and compound inhibitors,and the research progress of new phosphorus-based inhibitors was especially described.In this paper,the research results of various inhibitors in the laboratory were summarized,and the ideas for research and development of new inhibitors in the future were put forward.The application effect of inhibitors under actual incineration conditions was summarized;since the actual incineration conditions were complex and variable,the control effect of inhibitors on dioxins was unstable and difficult to reach the performance level of laboratory test.Therefore,the application and promotion of inhibitors in the actual MSW incineration process still need to be further studied and optimized.
Dioxins can cause persistent organic pollution and harm to the environment.Since the discovery of dioxins in the flue gas of municipal solid waste (MSW) incineration in the 1980s,many basic and applied researches have been carried out on the control of dioxins emission.Chemical inhibitors,which can inhibit the formation of dioxins during the incineration process,have been the research hotspot in this field.In this paper,the formation mechanism of dioxins and the current control strategies were introduced,and the advantages of using inhibitors were put forward.The types and mechanisms of dioxin inhibitors were reviewed,including the commonly used nitrogen/sulfur-based inhibitors,alkaline inhibitors and compound inhibitors,and the research progress of new phosphorus-based inhibitors was especially described.In this paper,the research results of various inhibitors in the laboratory were summarized,and the ideas for research and development of new inhibitors in the future were put forward.The application effect of inhibitors under actual incineration conditions was summarized;since the actual incineration conditions were complex and variable,the control effect of inhibitors on dioxins was unstable and difficult to reach the performance level of laboratory test.Therefore,the application and promotion of inhibitors in the actual MSW incineration process still need to be further studied and optimized.
2022, 40(7): 232-239,131.
doi: DOI:10.13205/j.hjgc.202207032
Abstract:
Biomass gasification is an efficient way to realize the distributed development and energy conversion of biomass.It is versatile and flexible,contributes to the construction of clean energy systems,and has been widely investigated and applied worldwide.The bibliometric analysis combined with S-curve technique and visualization tools were applied to quantitatively analyze 12034 articles related to biomass gasification research based on the Web of Science Core Collection in 2001-2020.The results indicated that the article number on biomass gasification increased from 58 in 2001 to 1517 in 2020,with a steady annual increment rate.The S-curve from articles indicated that biomass gasification technology was attached with great potential for innovation and development in the next 15 years.China had the highest number of publications (3201,26.60% of global output) and occupied a core position in the international cooperation network,whereas the papers published in the European countries and the United States were of higher impact.The co-occurrence and evolution path of keywords indicated that value-added utilization of byproducts from biomass gasification,development of new gasification processes (coupling process,chemical looping gasification),contribution to carbon neutrality,and evaluation on energy,exergy,economic,environmental benefits have become the new focus of biomass gasification research.
Biomass gasification is an efficient way to realize the distributed development and energy conversion of biomass.It is versatile and flexible,contributes to the construction of clean energy systems,and has been widely investigated and applied worldwide.The bibliometric analysis combined with S-curve technique and visualization tools were applied to quantitatively analyze 12034 articles related to biomass gasification research based on the Web of Science Core Collection in 2001-2020.The results indicated that the article number on biomass gasification increased from 58 in 2001 to 1517 in 2020,with a steady annual increment rate.The S-curve from articles indicated that biomass gasification technology was attached with great potential for innovation and development in the next 15 years.China had the highest number of publications (3201,26.60% of global output) and occupied a core position in the international cooperation network,whereas the papers published in the European countries and the United States were of higher impact.The co-occurrence and evolution path of keywords indicated that value-added utilization of byproducts from biomass gasification,development of new gasification processes (coupling process,chemical looping gasification),contribution to carbon neutrality,and evaluation on energy,exergy,economic,environmental benefits have become the new focus of biomass gasification research.
2022, 40(7): 240-247.
doi: DOI:10.13205/j.hjgc.202207033
Abstract:
The middle and lower reaches of the Yangtze River Basin plain play an important role in livestock and poultry breeding areas in China.Improving the treatment and utilization level of livestock and poultry manure in this area is of great significance to protect the environment of the Yangtze River Basin and promote the sustainable development of the regional economy.To better track the progress of the treatment and utilization of manure and wastewater,a nationwide survey was conducted in 2018-2020,covering 429 pig,cattle and poultry farms.The technical pathway and facility construction for the treatment and utilization of manure and wastewater were thoroughly analyzed,from the aspects of the collection methods,treatment technologies,and utilization to the farmland.The results showed that dry-dung cleaning was the main method for manure and wastewater collection in most surveyed farms (85.71%),while water flushing and deep-pit were frequently adopted in 8.2% and 2.58% of the surveyed farms.Composting was widely used in the treatment of solid feces,accounting for 91% of the surveyed farms.Most of the treated manure and wastewater were used for fertilizers for the farmland with fruits and vegetables,while their application to the farmland with grain crops was still low.Only 25.56% of the large-scale livestock and poultry farms had insufficient farmland for manure and wastewater consumption.The overall dosage based on nitrogen demand was relatively higher than plant need,which caused water pollution.Meanwhile,manual fertilization was still the main method compared with mechanical fertilization.To improve the treatment and utilization of livestock and poultry manure and wastewater,it was suggested to further standardize and improve the utilization technologies of manure and sewage resources,improve the technology and equipment level of manure and sewage resources utilization,guide large-scale farms to prepare the consuming land according to the requirements of planting and breeding balance,and strengthen the tracking and evaluation of farmland soil applying manure,so as to improve the utilization level of manure.
The middle and lower reaches of the Yangtze River Basin plain play an important role in livestock and poultry breeding areas in China.Improving the treatment and utilization level of livestock and poultry manure in this area is of great significance to protect the environment of the Yangtze River Basin and promote the sustainable development of the regional economy.To better track the progress of the treatment and utilization of manure and wastewater,a nationwide survey was conducted in 2018-2020,covering 429 pig,cattle and poultry farms.The technical pathway and facility construction for the treatment and utilization of manure and wastewater were thoroughly analyzed,from the aspects of the collection methods,treatment technologies,and utilization to the farmland.The results showed that dry-dung cleaning was the main method for manure and wastewater collection in most surveyed farms (85.71%),while water flushing and deep-pit were frequently adopted in 8.2% and 2.58% of the surveyed farms.Composting was widely used in the treatment of solid feces,accounting for 91% of the surveyed farms.Most of the treated manure and wastewater were used for fertilizers for the farmland with fruits and vegetables,while their application to the farmland with grain crops was still low.Only 25.56% of the large-scale livestock and poultry farms had insufficient farmland for manure and wastewater consumption.The overall dosage based on nitrogen demand was relatively higher than plant need,which caused water pollution.Meanwhile,manual fertilization was still the main method compared with mechanical fertilization.To improve the treatment and utilization of livestock and poultry manure and wastewater,it was suggested to further standardize and improve the utilization technologies of manure and sewage resources,improve the technology and equipment level of manure and sewage resources utilization,guide large-scale farms to prepare the consuming land according to the requirements of planting and breeding balance,and strengthen the tracking and evaluation of farmland soil applying manure,so as to improve the utilization level of manure.
2022, 40(7): 248-252.
doi: DOI:10.13205/j.hjgc.202207034
Abstract:
The transportation of sludge ensures the stable and efficient operation of other links of sludge treatment and disposal.In many ways of sludge transportation,pipeline transportation of sludge is closed,safer and more efficient compared with the traditional truck transportation,which has become the research focus of sludge transportation industry.In the design of sludge pipeline transportation system,it is very important to calculate the pipeline pressure required for transporting sludge,but the calculation of pipeline pressure is easily affected by the rheological characteristics of sludge.This paper first introduces the influencing factors of sludge rheological characteristics such as temperature,moisture content,pH value and shear rate of sludge.Secondly,the research status of pipeline transportation of sludge with moisture content higher than 90% and sludge with moisture content of 60%~90% is summarized,the energy consumption and cost of sludge pipeline transportation are also analyzed.The pipeline transportation was applicable to the transportation of sludge treatment and disposal of underground sewage treatment plants in urban central areas.Finally,methods of improving the transportation mode of sludge in the pipeline and flow characteristics of the sludge are expounded to improve the transportation efficiency of sludge pipeline and reduce the operation and maintenance cost of pipeline transportation.
The transportation of sludge ensures the stable and efficient operation of other links of sludge treatment and disposal.In many ways of sludge transportation,pipeline transportation of sludge is closed,safer and more efficient compared with the traditional truck transportation,which has become the research focus of sludge transportation industry.In the design of sludge pipeline transportation system,it is very important to calculate the pipeline pressure required for transporting sludge,but the calculation of pipeline pressure is easily affected by the rheological characteristics of sludge.This paper first introduces the influencing factors of sludge rheological characteristics such as temperature,moisture content,pH value and shear rate of sludge.Secondly,the research status of pipeline transportation of sludge with moisture content higher than 90% and sludge with moisture content of 60%~90% is summarized,the energy consumption and cost of sludge pipeline transportation are also analyzed.The pipeline transportation was applicable to the transportation of sludge treatment and disposal of underground sewage treatment plants in urban central areas.Finally,methods of improving the transportation mode of sludge in the pipeline and flow characteristics of the sludge are expounded to improve the transportation efficiency of sludge pipeline and reduce the operation and maintenance cost of pipeline transportation.
