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2021 Vol. 39, No. 9
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2021, 39(9): 7-13,75.
doi: 10.13205/j.hjgc.202109002
Abstract:
With the rapid development of nanotechnology, nanoceria (nano-CeO2) with novel physicochemical properties are widely applied in industrial and consumer products. It is inevitable for the increasing quantities of nano-CeO2 being released into the wastewater treatment plants (WWTPs), which would further impose adverse effect on wastewater purification and stable operation of WWTPs. In this review, the fates and transformations of nano-CeO2, the effects of nano-CeO2 on the surface properties, functional activities and community composition of microbes were systemically discussed to illustrate the environmental behaviors and toxicity effects of nano-CeO2 on WWTPs. Furthermore, the influences of nano-CeO2 on WWTPs and strategies to attenuate the negative effects of nano-CeO2 on WWTPs were summarized. This paper was aimed to provide theorical and scientific basis for controlling and preventing the environmental risks of nano-CeO2 in WWTPs.
With the rapid development of nanotechnology, nanoceria (nano-CeO2) with novel physicochemical properties are widely applied in industrial and consumer products. It is inevitable for the increasing quantities of nano-CeO2 being released into the wastewater treatment plants (WWTPs), which would further impose adverse effect on wastewater purification and stable operation of WWTPs. In this review, the fates and transformations of nano-CeO2, the effects of nano-CeO2 on the surface properties, functional activities and community composition of microbes were systemically discussed to illustrate the environmental behaviors and toxicity effects of nano-CeO2 on WWTPs. Furthermore, the influences of nano-CeO2 on WWTPs and strategies to attenuate the negative effects of nano-CeO2 on WWTPs were summarized. This paper was aimed to provide theorical and scientific basis for controlling and preventing the environmental risks of nano-CeO2 in WWTPs.
2021, 39(9): 14-22.
doi: 10.13205/j.hjgc.202109003
Abstract:
The wastewater purification in subsurface flow constructed wetland is realized by the combined functions of substrate, microbes, and plant. Substrate, as an important element, plays critical role in wastewater purification. Firstly, substrate could directly absorb pollutants. The efficiency of pollutant absorbance varies with the substrate material, which is also influenced by the water quality, hydraulic condition, etc. Secondly, substrate could provide the surface for microbes to form biofilm. The properties of substrate, e.g. the material, the saturated/unsaturated condition of substrate, the inner porous structure, and specific surface area, all affect the formation and development of biofilm, as well as the wastewater purification indirectly. Increasing the unsaturated area of substrate, adding the material that could slow-release carbon source, adding Fe-C micro-electrolysis material could improve the removal of ammonia, total nitrogen, and phosphorus by enhancing the oxygen supplement, denitrification process and the chemical sedimentation process, respectively.
The wastewater purification in subsurface flow constructed wetland is realized by the combined functions of substrate, microbes, and plant. Substrate, as an important element, plays critical role in wastewater purification. Firstly, substrate could directly absorb pollutants. The efficiency of pollutant absorbance varies with the substrate material, which is also influenced by the water quality, hydraulic condition, etc. Secondly, substrate could provide the surface for microbes to form biofilm. The properties of substrate, e.g. the material, the saturated/unsaturated condition of substrate, the inner porous structure, and specific surface area, all affect the formation and development of biofilm, as well as the wastewater purification indirectly. Increasing the unsaturated area of substrate, adding the material that could slow-release carbon source, adding Fe-C micro-electrolysis material could improve the removal of ammonia, total nitrogen, and phosphorus by enhancing the oxygen supplement, denitrification process and the chemical sedimentation process, respectively.
2021, 39(9): 23-30.
doi: 10.13205/j.hjgc.202109004
Abstract:
It is urgent to improve the quality and efficiency of urban drainage system in China. The analysis of water composition of drainage system is an important basic work in the building of background information frame. Due to the high efficiency and economy of using marker species to analyze the water quantity of drainage system, the selection of marker species and the improvement of calculation method of this method have been studied and discussed in recent years, among which the reasonable selection of marker species of different pollution sources was the core of application of this method. In order to improve the accuracy of water composition analysis of drainage system based on marker species, the application status and existing problems were discussed. Based on the consideration of the application status of marker species of drainage system in China, combined with the application practice of many cities at home and abroad, this paper comprehensively analyzed the types of marker species, basis for their selection and long-term problems in the source apportionment, and put forward the key research and development direction of relevant marker species in the water quantity composition analysis of drainage system in China. It provided an important theoretical reference for improving the quality and efficiency of drainage system in China during the 14th Five Year Plan period.
It is urgent to improve the quality and efficiency of urban drainage system in China. The analysis of water composition of drainage system is an important basic work in the building of background information frame. Due to the high efficiency and economy of using marker species to analyze the water quantity of drainage system, the selection of marker species and the improvement of calculation method of this method have been studied and discussed in recent years, among which the reasonable selection of marker species of different pollution sources was the core of application of this method. In order to improve the accuracy of water composition analysis of drainage system based on marker species, the application status and existing problems were discussed. Based on the consideration of the application status of marker species of drainage system in China, combined with the application practice of many cities at home and abroad, this paper comprehensively analyzed the types of marker species, basis for their selection and long-term problems in the source apportionment, and put forward the key research and development direction of relevant marker species in the water quantity composition analysis of drainage system in China. It provided an important theoretical reference for improving the quality and efficiency of drainage system in China during the 14th Five Year Plan period.
2021, 39(9): 31-36.
doi: 10.13205/j.hjgc.202109005
Abstract:
This study compared the membrane fouling behavior and water purification performance of aerobic granular sludge membrane bioreactor (AGMBR) and traditional flocculent sludge membrane bioreactor (MBR) for the treatment of substation sewage. Using substation domestic sewage as the feed water, aerobic granular sludge could be successfully cultivated after 60 days. Compared with traditional flocculent sludge, aerobic granular sludge could effectively slow down membrane fouling, especially irreversible membrane fouling. In AGMBR, the hydraulic backwash frequency was only 33.3% of that in traditional MBR, and the resistance from pore blocking in 30-day continuous operation was only 69.3% of traditional MBR. Further analysis suggested that EPS content in AGMBR reactor was significantly lower than that of traditional MBR, and the content of polysaccharide in EPS was only 46% of the traditional MBR. The comparison result in water purification performance showed that AGMBR had an excellent removal performance for TN and TP, and the average removal rate of 30-day running was 37.8% and 40.5% higher than that of the traditional MBR, respectively.
This study compared the membrane fouling behavior and water purification performance of aerobic granular sludge membrane bioreactor (AGMBR) and traditional flocculent sludge membrane bioreactor (MBR) for the treatment of substation sewage. Using substation domestic sewage as the feed water, aerobic granular sludge could be successfully cultivated after 60 days. Compared with traditional flocculent sludge, aerobic granular sludge could effectively slow down membrane fouling, especially irreversible membrane fouling. In AGMBR, the hydraulic backwash frequency was only 33.3% of that in traditional MBR, and the resistance from pore blocking in 30-day continuous operation was only 69.3% of traditional MBR. Further analysis suggested that EPS content in AGMBR reactor was significantly lower than that of traditional MBR, and the content of polysaccharide in EPS was only 46% of the traditional MBR. The comparison result in water purification performance showed that AGMBR had an excellent removal performance for TN and TP, and the average removal rate of 30-day running was 37.8% and 40.5% higher than that of the traditional MBR, respectively.
2021, 39(9): 37-41.
doi: 10.13205/j.hjgc.202109006
Abstract:
It is a kind of green economy wastewater treatment method to use the optimized microalgae for secondary treatment of swine wastewater, which has considerable application prospect. Combining isotope tracer method and path analysis, the phosphorus metabolic and mechanism analysis in biogas slurry by Oedogonium sp. were studied, in order to provide theoretical basis for practical application of Oedogonium sp. in digested wastewater treatment. During the experiment, Chl-a content in the biogas slurry reached 3.35 mg/L, 3.13 times of the initial content, and the TP removal rate was 91.22%. The analysis of TP removal mechanism showed that the microbial residues in the wastewater had little influence on TP removal. It was difficult to form gaseous phosphine from biogas slurry into the atmosphere under aerobic state. About 30% of TP was removed by phosphate precipitation under alkaline condition with the synergistic effect of cation such as Ca2+ and Mg2+. TP decrease was mainly caused by the algal incorporation and phosphate precipitation. About 60% of TP was removed by microalgae assimilation. The DO value should be reduced and the N/P ratio should be maintained for further improving TP removal rate.
It is a kind of green economy wastewater treatment method to use the optimized microalgae for secondary treatment of swine wastewater, which has considerable application prospect. Combining isotope tracer method and path analysis, the phosphorus metabolic and mechanism analysis in biogas slurry by Oedogonium sp. were studied, in order to provide theoretical basis for practical application of Oedogonium sp. in digested wastewater treatment. During the experiment, Chl-a content in the biogas slurry reached 3.35 mg/L, 3.13 times of the initial content, and the TP removal rate was 91.22%. The analysis of TP removal mechanism showed that the microbial residues in the wastewater had little influence on TP removal. It was difficult to form gaseous phosphine from biogas slurry into the atmosphere under aerobic state. About 30% of TP was removed by phosphate precipitation under alkaline condition with the synergistic effect of cation such as Ca2+ and Mg2+. TP decrease was mainly caused by the algal incorporation and phosphate precipitation. About 60% of TP was removed by microalgae assimilation. The DO value should be reduced and the N/P ratio should be maintained for further improving TP removal rate.
2021, 39(9): 42-47.
doi: 10.13205/j.hjgc.202109007
Abstract:
Biogas slurry contains appreciable levels of nitrogen, particularly ammonia that can lead to potential air and water quality problems. In this study, the ammonia-nitrogen treatment capacity and biomass utilization potential of Chlorella was tested at different pH levels. Chlorella was cultivated in simulated wastewater at four different pH levels (6.5, 7.5, 8.5, 9.5) with initial ammonia nitrogen concentration in the range of 120~130 mg/L. The results showed that the removal of ammonia nitrogen was better at pH 6.5~7.5. When pH increased more than 8.5, high concentration of free ammonia had a major inhibitory effect on the growth of Chlorella. In terms of chlorophyll accumulation in algal cells, Chlorella preferred a pH range from 6.5 to 8.5. The highest lipid producitivity of Chlorella (0.30 g/L/d) was achieved at pH7.5, which was consistent with the suitable pH condition for Chlorella growth. It is proposed that controlling pH value between 6.5~7.5 would be conduciue for removal of ammonia nitrogen and wastewater recycling when using Chlorella to treat biogas slurry.
Biogas slurry contains appreciable levels of nitrogen, particularly ammonia that can lead to potential air and water quality problems. In this study, the ammonia-nitrogen treatment capacity and biomass utilization potential of Chlorella was tested at different pH levels. Chlorella was cultivated in simulated wastewater at four different pH levels (6.5, 7.5, 8.5, 9.5) with initial ammonia nitrogen concentration in the range of 120~130 mg/L. The results showed that the removal of ammonia nitrogen was better at pH 6.5~7.5. When pH increased more than 8.5, high concentration of free ammonia had a major inhibitory effect on the growth of Chlorella. In terms of chlorophyll accumulation in algal cells, Chlorella preferred a pH range from 6.5 to 8.5. The highest lipid producitivity of Chlorella (0.30 g/L/d) was achieved at pH7.5, which was consistent with the suitable pH condition for Chlorella growth. It is proposed that controlling pH value between 6.5~7.5 would be conduciue for removal of ammonia nitrogen and wastewater recycling when using Chlorella to treat biogas slurry.
2021, 39(9): 48-55.
doi: 10.13205/j.hjgc.202109008
Abstract:
In order to prepare environmental-friendly adsorption materials with magnetic separation and excellent adsorption properties, the effect of different preparation methods on the adsorption properties of biochar was investigated. Fir wood (FW) pruned from deforestation residues was used as the feedstock. The original biochar FWBC was obtained by pyrolysis of FW at high temperature. Magnetic biochars FWFe(2) and FWFe(3) were prepared by two methods:precipitation and impregnation. The biochar was characterized by elemental analysis, magnetic analysis, SEM-EDS, XRD and FTIR. The adsorption characteristics of FWFe(2) and FWFe(3) for Pb2+in water were studied. The adsorption mechanisms of different biochars were discussed. The results showed that the magnetized biochars contained Fe3O4 particles. The saturation magnetization of FWFe (2) and FWFe (3) were 35.59 and 27.76 emu/g, respectively, which indicated good magnetic separation capability for all kinds of biochars. The Pb2+adsorption characteristics by FWFe (2) and FWFe (3) were more in line with the pseudo second order kinetics and Langmuir isotherm model, which indicated that the adsorption was mainly chemical adsorption. The adsorption performance of the magnetized FWFe(2) was significantly better than that of FWFe(3) and the original biochar. The equilibrium adsorption capacity was 817.64 mg/g, which was 12 times of that of FWBC. Magnetization by precipitation method could effectively improve the adsorption of Pb2+. The adsorption mechanism mainly included ion exchange and metal (hydrogen) carbonate coprecipitation, physical adsorption and complexation with surface functional groups. The results were helpful to promote the utilization of agricultural and forestry waste biomass and the practical application of magnetic biochar in environment.
In order to prepare environmental-friendly adsorption materials with magnetic separation and excellent adsorption properties, the effect of different preparation methods on the adsorption properties of biochar was investigated. Fir wood (FW) pruned from deforestation residues was used as the feedstock. The original biochar FWBC was obtained by pyrolysis of FW at high temperature. Magnetic biochars FWFe(2) and FWFe(3) were prepared by two methods:precipitation and impregnation. The biochar was characterized by elemental analysis, magnetic analysis, SEM-EDS, XRD and FTIR. The adsorption characteristics of FWFe(2) and FWFe(3) for Pb2+in water were studied. The adsorption mechanisms of different biochars were discussed. The results showed that the magnetized biochars contained Fe3O4 particles. The saturation magnetization of FWFe (2) and FWFe (3) were 35.59 and 27.76 emu/g, respectively, which indicated good magnetic separation capability for all kinds of biochars. The Pb2+adsorption characteristics by FWFe (2) and FWFe (3) were more in line with the pseudo second order kinetics and Langmuir isotherm model, which indicated that the adsorption was mainly chemical adsorption. The adsorption performance of the magnetized FWFe(2) was significantly better than that of FWFe(3) and the original biochar. The equilibrium adsorption capacity was 817.64 mg/g, which was 12 times of that of FWBC. Magnetization by precipitation method could effectively improve the adsorption of Pb2+. The adsorption mechanism mainly included ion exchange and metal (hydrogen) carbonate coprecipitation, physical adsorption and complexation with surface functional groups. The results were helpful to promote the utilization of agricultural and forestry waste biomass and the practical application of magnetic biochar in environment.
2021, 39(9): 56-62.
doi: 10.13205/j.hjgc.202109009
Abstract:
N2O is a potent greenhouse gas, and releases a lot in wastewater treatment. Understanding the influencing factors of N2O release in wastewater treatment can reduce N2O emissions. Four classical external organic carbon sources, such as sodium acetate, ethanol, glucose and sucrose, were used to study the N2O release process in denitrification process with SBR reactors. The results showed that under the 4 carbon source conditions, the accumulation of N2O showed a trend of first increasing, then decreasing, and finally remaining stable. The maximum accumulation of N2O were 1.59, 1.25, 5.43, 0.66 mg/L, and the maximum conversion rates were 1.61%, 1.36%, 5.44% and 0.67%, respectively. The final accumulation of N2O were 1.02, 0.67, 3.12, 0.49 mg/L, and the final conversion rates were 1.04%, 0.73%, 3.13% and 0.50%, respectively. The N2O release amount and conversion rate in descending order were glucose, sodium acetate, ethanol and sucrose. FNA inhibition, electronic competition of different denitrifying enzymes and differences in microbial community structure were factors affecting N2O release.
N2O is a potent greenhouse gas, and releases a lot in wastewater treatment. Understanding the influencing factors of N2O release in wastewater treatment can reduce N2O emissions. Four classical external organic carbon sources, such as sodium acetate, ethanol, glucose and sucrose, were used to study the N2O release process in denitrification process with SBR reactors. The results showed that under the 4 carbon source conditions, the accumulation of N2O showed a trend of first increasing, then decreasing, and finally remaining stable. The maximum accumulation of N2O were 1.59, 1.25, 5.43, 0.66 mg/L, and the maximum conversion rates were 1.61%, 1.36%, 5.44% and 0.67%, respectively. The final accumulation of N2O were 1.02, 0.67, 3.12, 0.49 mg/L, and the final conversion rates were 1.04%, 0.73%, 3.13% and 0.50%, respectively. The N2O release amount and conversion rate in descending order were glucose, sodium acetate, ethanol and sucrose. FNA inhibition, electronic competition of different denitrifying enzymes and differences in microbial community structure were factors affecting N2O release.
2021, 39(9): 63-68,91.
doi: 10.13205/j.hjgc.202109010
Abstract:
The barrier wall can prevent the diffusion of pollutants in groundwater effectively. Taking cement soil as the research object, the performance of the barrier wall was studied through laboratory penetration test, stability experiment, adsorption experiment and engineering case study. The results showed that with the increase of cement content, the permeability coefficient of cement-soil decreased continuously. Silty clay, clayey silty and silty sand with the cement content of 12%, 20% and 25% had good anti-permeability effect. The unconfined compressive strength increased with the increase of cement content, and the increase of compressive strength of silty sand cement soil barrier wall was obvious. The higher the clay content of soil, the greater the water-cement ratio was to meet the slump requirement of cement soil. The adsorption isotherms conformed to Freundlich model and the soil-cement adsorbed Cu2+ and Zn2+ better than tetrachlorophenol and Cr(Ⅵ). The adsorption kinetics conformed to the quasi-secondary adsorption kinetic equation and the adsorption process was mainly chemical adsorption. The equilibrium adsorption capacity of Cu2+ and Zn2+ adsorbed by silty clay cement soil was the highest (equaled to 7.692, 7.143 mg/g, respectively). The engineering application proved that the cement-soil barrier wall had remarkable control effect on petroleum hydrocarbon pollutants in groundwater and the detection concentration of monitoring wells was lower than the risk control value.
The barrier wall can prevent the diffusion of pollutants in groundwater effectively. Taking cement soil as the research object, the performance of the barrier wall was studied through laboratory penetration test, stability experiment, adsorption experiment and engineering case study. The results showed that with the increase of cement content, the permeability coefficient of cement-soil decreased continuously. Silty clay, clayey silty and silty sand with the cement content of 12%, 20% and 25% had good anti-permeability effect. The unconfined compressive strength increased with the increase of cement content, and the increase of compressive strength of silty sand cement soil barrier wall was obvious. The higher the clay content of soil, the greater the water-cement ratio was to meet the slump requirement of cement soil. The adsorption isotherms conformed to Freundlich model and the soil-cement adsorbed Cu2+ and Zn2+ better than tetrachlorophenol and Cr(Ⅵ). The adsorption kinetics conformed to the quasi-secondary adsorption kinetic equation and the adsorption process was mainly chemical adsorption. The equilibrium adsorption capacity of Cu2+ and Zn2+ adsorbed by silty clay cement soil was the highest (equaled to 7.692, 7.143 mg/g, respectively). The engineering application proved that the cement-soil barrier wall had remarkable control effect on petroleum hydrocarbon pollutants in groundwater and the detection concentration of monitoring wells was lower than the risk control value.
2021, 39(9): 69-75.
doi: 10.13205/j.hjgc.202109011
Abstract:
The Huangzhouhe River is one of the important rivers in the Shibing Karst Word Natural Heritage Site. In order to know the water quality characteristics of the Huangzhouhe River, single factor water quality identification index, mean-type comprehensive pollution index, cluster analysis and principal component analysis were used to analyze and evaluate the river water quality characteristics, based on 8 sample points, 7 monitoring indicators and 12-month monitoring data. The results showed that TN to excessive emission standard was severe in the river, and TP excessive potential was strong. Water quality in heritage site's core area didn't meet the class I standard, and that in the buffer zone was inferior to class Ⅲ water quality standard. The water quality was worse in high water period and better in low water period. TP, NTU and NH3-N were the main controlling factors in the wet season. CODMn, Chl-a and DO were the main control factors in the leveling period. The main controlling factor in the dry season was NH3-N. The main form of pollution in the basin was agricultural non-point source pollution. The current situation of heavy pollution of the monitoring point, Y1 and Y2 were caused by the domestic water of residents in the upstream and midstream buffer zones and pollution discharge of livestock and poultry excrement in rural areas. Moreover, the pollution will migrate with the river and enter the core area of the natural heritage site.
The Huangzhouhe River is one of the important rivers in the Shibing Karst Word Natural Heritage Site. In order to know the water quality characteristics of the Huangzhouhe River, single factor water quality identification index, mean-type comprehensive pollution index, cluster analysis and principal component analysis were used to analyze and evaluate the river water quality characteristics, based on 8 sample points, 7 monitoring indicators and 12-month monitoring data. The results showed that TN to excessive emission standard was severe in the river, and TP excessive potential was strong. Water quality in heritage site's core area didn't meet the class I standard, and that in the buffer zone was inferior to class Ⅲ water quality standard. The water quality was worse in high water period and better in low water period. TP, NTU and NH3-N were the main controlling factors in the wet season. CODMn, Chl-a and DO were the main control factors in the leveling period. The main controlling factor in the dry season was NH3-N. The main form of pollution in the basin was agricultural non-point source pollution. The current situation of heavy pollution of the monitoring point, Y1 and Y2 were caused by the domestic water of residents in the upstream and midstream buffer zones and pollution discharge of livestock and poultry excrement in rural areas. Moreover, the pollution will migrate with the river and enter the core area of the natural heritage site.
2021, 39(9): 76-83.
doi: 10.13205/j.hjgc.202109012
Abstract:
This article mainly investigated the stability of anammox microbial fuel cell (ANAMMOX-MFC) high-efficiency denitrification and electricity generation operation with the addition of subsequent carbon sources, and used high-throughput sequencing and KEGG functional enzymes to predict changes in microbial community structure and functional genes characterization. The results showed that the system could run continuously and get stably for 60 days, the total nitrogen removal rate was 96% above, and the maximum output voltage of continuous operation was about 800 mV. Adding a proper concentration of sodium acetate could increase the relative abundance of the fermenting bacteria Enterococcus, denitrifying electricity-producing bacteria Pseudomonas, and Thaurea in the sludge, thereby effectively promoting electricity production. However, excessive hydrolysis and acidification will inhibit AnAOB activity. From the 68th to the 104th day, the ammonia nitrogen concentration in the effluent increased, and the total nitrogen removal rate dropped to about 90%. The total nitrogen removal rate was restored to 95% above by stopping the sodium acetate. The NH4+-N concentration in the effluent of the ANAMMOX-MFC system could be used as a "regulation signal" for the subsequent stop of the carbon source, so that the denitrification and electricity generation system could run stably and efficiently. It provides a combination of anaerobic ammonia oxidation and microbial fuel cell denitrification and electricity generation technology and has a good theoretical basis and certain engineering significance.
This article mainly investigated the stability of anammox microbial fuel cell (ANAMMOX-MFC) high-efficiency denitrification and electricity generation operation with the addition of subsequent carbon sources, and used high-throughput sequencing and KEGG functional enzymes to predict changes in microbial community structure and functional genes characterization. The results showed that the system could run continuously and get stably for 60 days, the total nitrogen removal rate was 96% above, and the maximum output voltage of continuous operation was about 800 mV. Adding a proper concentration of sodium acetate could increase the relative abundance of the fermenting bacteria Enterococcus, denitrifying electricity-producing bacteria Pseudomonas, and Thaurea in the sludge, thereby effectively promoting electricity production. However, excessive hydrolysis and acidification will inhibit AnAOB activity. From the 68th to the 104th day, the ammonia nitrogen concentration in the effluent increased, and the total nitrogen removal rate dropped to about 90%. The total nitrogen removal rate was restored to 95% above by stopping the sodium acetate. The NH4+-N concentration in the effluent of the ANAMMOX-MFC system could be used as a "regulation signal" for the subsequent stop of the carbon source, so that the denitrification and electricity generation system could run stably and efficiently. It provides a combination of anaerobic ammonia oxidation and microbial fuel cell denitrification and electricity generation technology and has a good theoretical basis and certain engineering significance.
2021, 39(9): 84-91.
doi: 10.13205/j.hjgc.202109013
Abstract:
The urban spatial structure affects the microenvironment such as air circulation, which inevitably has an impact on PM2.5 distribution and dispersion. Studying the relationship between the two has positive significance for urban planning and construction. Based on the construction of the urban spatial structure indicators system, the spatial pattern of PM2.5 concentrations in the central city of Jinan was studied using methods of kriging interpolation, and the influence of urban spatial structure on PM2.5 distribution was investigated based on the whole area and different elevation perspectives using correlation analysis methods. The results showed that:1) PM2.5 concentration was negatively correlated with the average and standard deviation of DEM, the average and standard deviation of absolute building height, and outdoor activity area, and positively correlated with the maximum absolute building height, the sum of building floor area, building density, occupancy ratio, and the sum of building volume. These indicators were important factors affecting the distribution of PM2.5 and should be considered in urban planning and layout. 2) there were spatial and temporal differences in PM2.5 distribution at different elevations and time ranges. the higher the PM2.5 concentration, the more obvious the influence of urban spatial structure indicators on its concentration distribution, the coefficient of variation of PM2.5 concentration spatial distribution increased, and the correlation between PM2.5 concentration and each urban structure indicator became weaker. 3) topographic elevation was an important factor influencing the distribution of PM2.5. As the average elevation increased, the number of months with significant correlation between urban spatial structure indicators and PM2.5 concentrations increased, and the regularity got stronger.
The urban spatial structure affects the microenvironment such as air circulation, which inevitably has an impact on PM2.5 distribution and dispersion. Studying the relationship between the two has positive significance for urban planning and construction. Based on the construction of the urban spatial structure indicators system, the spatial pattern of PM2.5 concentrations in the central city of Jinan was studied using methods of kriging interpolation, and the influence of urban spatial structure on PM2.5 distribution was investigated based on the whole area and different elevation perspectives using correlation analysis methods. The results showed that:1) PM2.5 concentration was negatively correlated with the average and standard deviation of DEM, the average and standard deviation of absolute building height, and outdoor activity area, and positively correlated with the maximum absolute building height, the sum of building floor area, building density, occupancy ratio, and the sum of building volume. These indicators were important factors affecting the distribution of PM2.5 and should be considered in urban planning and layout. 2) there were spatial and temporal differences in PM2.5 distribution at different elevations and time ranges. the higher the PM2.5 concentration, the more obvious the influence of urban spatial structure indicators on its concentration distribution, the coefficient of variation of PM2.5 concentration spatial distribution increased, and the correlation between PM2.5 concentration and each urban structure indicator became weaker. 3) topographic elevation was an important factor influencing the distribution of PM2.5. As the average elevation increased, the number of months with significant correlation between urban spatial structure indicators and PM2.5 concentrations increased, and the regularity got stronger.
2021, 39(9): 92-101,109.
doi: 10.13205/j.hjgc.202109014
Abstract:
Use the Trajstat plug-in in the Meteoinfo software to simulate the backward trajectory of the air masses arriving in Jiayuguan City from March 2019 to February 2020, and combine the data of various air pollutants to perform a cluster analysis of the backward trajectory of Jiayuguan City in the four seasons. In this way, we studied the main air masses transportation path and the pollutant concentration characteristics of the corresponding path to Jiayuguan City. The potential source contribution function (PSCF) and concentration weighted trajectory (CWT) were used to analyze the impact of pollutant transportation sources and main potential source areas and the transmission of air pollutants on air quality in Jiayuguan City. Among the air masses transported into Jiayuguan City, the number of air mass trajectories in the northwest and the percentage of pollution trajectories were larger than those in the other directions. The air pollution in Jiayuguan City in four seasons was more susceptible to the influence of air masses in the northwest. Jiayuguan City had relatively serious PM10 pollution in spring and was more susceptible to potential source areas in eastern Xinjiang, and PM10 pollution in other seasons was relatively light. The potential source areas were mainly concentrated in eastern Xinjiang, with a few located in the northeast of Jiayuguan City. The O3 pollution in Jiayuguan City in spring and summer was relatively serious. The strong potential source areas were mainly concentrated in eastern Xinjiang and the Hexi Corridor area of Gansu. The O3 pollution in autumn and winter was relatively light. The potential source area in autumn was mainly located in the Hexi Corridor area of Gansu, and the potential source area in winter was mainly located in eastern Xinjiang.
Use the Trajstat plug-in in the Meteoinfo software to simulate the backward trajectory of the air masses arriving in Jiayuguan City from March 2019 to February 2020, and combine the data of various air pollutants to perform a cluster analysis of the backward trajectory of Jiayuguan City in the four seasons. In this way, we studied the main air masses transportation path and the pollutant concentration characteristics of the corresponding path to Jiayuguan City. The potential source contribution function (PSCF) and concentration weighted trajectory (CWT) were used to analyze the impact of pollutant transportation sources and main potential source areas and the transmission of air pollutants on air quality in Jiayuguan City. Among the air masses transported into Jiayuguan City, the number of air mass trajectories in the northwest and the percentage of pollution trajectories were larger than those in the other directions. The air pollution in Jiayuguan City in four seasons was more susceptible to the influence of air masses in the northwest. Jiayuguan City had relatively serious PM10 pollution in spring and was more susceptible to potential source areas in eastern Xinjiang, and PM10 pollution in other seasons was relatively light. The potential source areas were mainly concentrated in eastern Xinjiang, with a few located in the northeast of Jiayuguan City. The O3 pollution in Jiayuguan City in spring and summer was relatively serious. The strong potential source areas were mainly concentrated in eastern Xinjiang and the Hexi Corridor area of Gansu. The O3 pollution in autumn and winter was relatively light. The potential source area in autumn was mainly located in the Hexi Corridor area of Gansu, and the potential source area in winter was mainly located in eastern Xinjiang.
2021, 39(9): 102-109.
doi: 10.13205/j.hjgc.202109015
Abstract:
In this paper, the Ca-Mg-Al hydrotalcite-like was impregnated by K2CO3, and the derived mixed metal oxide adsorbent was obtained by further calcination. The fixed-bed experimental system was used to study the HCl(g) removal performance of K2CO3 modified hydrotalcite-like adsorbent at high temperature. The effects of K2CO3 content, reaction temperature and HCl(g) concentration on the removal of HCl(g) were investigated. The adsorbents were characterized by X-ray diffraction, specific surface area and pore analysis, scanning electron microscopy and thermogravimetric analysis. The results showed that:HCl(g) removal performance of hydrotalcite-like adsorbent modified by K2CO3 was significantly improved, and the optimum K2CO3 content was 30%. When the K2CO3 content exceeded 30%, the pore of adsorbent was blocked and the adsorption capacity was decreased. In the reaction temperature range of 400~800℃, the HCl(g) adsorption capacity of the adsorbent reached the maximum value of 0.289 g/g adsorbent at 600℃. After being calcined at 500℃, the specific surface area and pore volume of the adsorbent increased, the average pore size decreased, and the adsorption capacity was enhanced. The thermal stability of the hydrotalcite-like adsorbent was improved after impregnated by K2CO3. The high-temperature HCl(g) removal performance of K2CO3 modified hydrotalcite-like adsorbent was excellent, providing research directions for finding efficient and practical high-temperature HCl(g) removal adsorbents.
In this paper, the Ca-Mg-Al hydrotalcite-like was impregnated by K2CO3, and the derived mixed metal oxide adsorbent was obtained by further calcination. The fixed-bed experimental system was used to study the HCl(g) removal performance of K2CO3 modified hydrotalcite-like adsorbent at high temperature. The effects of K2CO3 content, reaction temperature and HCl(g) concentration on the removal of HCl(g) were investigated. The adsorbents were characterized by X-ray diffraction, specific surface area and pore analysis, scanning electron microscopy and thermogravimetric analysis. The results showed that:HCl(g) removal performance of hydrotalcite-like adsorbent modified by K2CO3 was significantly improved, and the optimum K2CO3 content was 30%. When the K2CO3 content exceeded 30%, the pore of adsorbent was blocked and the adsorption capacity was decreased. In the reaction temperature range of 400~800℃, the HCl(g) adsorption capacity of the adsorbent reached the maximum value of 0.289 g/g adsorbent at 600℃. After being calcined at 500℃, the specific surface area and pore volume of the adsorbent increased, the average pore size decreased, and the adsorption capacity was enhanced. The thermal stability of the hydrotalcite-like adsorbent was improved after impregnated by K2CO3. The high-temperature HCl(g) removal performance of K2CO3 modified hydrotalcite-like adsorbent was excellent, providing research directions for finding efficient and practical high-temperature HCl(g) removal adsorbents.
2021, 39(9): 110-116,198.
doi: 10.13205/j.hjgc.202109016
Abstract:
In order to explore the impact of the COVID-19 epidemic implementation policy on air pollution variation, ρ(PM2.5), ρ(PM10) and meteorological elements (temperature, relative humidity, wind direction, wind speed, atmospheric pressure and rainfall) were observed by the microenvironment platform on the roof of a high-rise dormitory building in the inner ring of Shanghai from January 14th, 2020 to February 18th, 2020. The characteristics and influencing factors of air pollutants before and after the implementation of the policy were analyzed through statistical analysis, synthetic analysis, Lagrangian particle dispersion model and Spearman correlation method, based on the above observation data in 2020 and the corresponding observation data in 2019, as well as the hourly monitoring data of gaseous pollutants (O3, NO2, CO, SO2) at Yangpu Sipiao air quality monitoring station. The results showed that:1) Changes in pollutant concentrations:the implementation of the policy reduced the magnitude of ρ(PM2.5), ρ(PM10) and ρ(NO2) significantly:ρ(PM2.5) and ρ(PM10) decreased from 61.4 μg/m3 to 38.1 μg/m3 and from 102.4 μg/m3 to 63.5 μg/m3, respectively, with a decrease rate of 38.0%, ρ(NO2) decreased from 57.3 μg/m3 to 27.0 μg/m3, with a decrease rate of 52.9%. ρ(O3) increased from 47.6 μg/m3 and 69.5 μg/m3. The diurnal bimodal and double-valley variation pattern of ρ(PM2.5) and ρ(PM10) became a single-valley pattern after the implementation of the policy; 2) The influence of meteorological factors:the anomaly of the southerly wind weakened the intensity of the winter monsoon, and the anomaly of the positive anomaly in the middle troposphere inhibited the development of convective activities, which easily led to the accumulation of atmospheric pollutants near the ground. ρ(PM2.5) and ρ(PM10) were negatively correlated with relative humidity. The influence of wind speed on ρ(PM2.5) and ρ(PM10) depended on the wind direction; 3) The impact of external sources:the urban agglomeration of the Yangtze River Delta and the surrounding provinces such as Shandong and Henan contributed significantly to ρ(PM2.5) and ρ(PM10) in Shanghai.
In order to explore the impact of the COVID-19 epidemic implementation policy on air pollution variation, ρ(PM2.5), ρ(PM10) and meteorological elements (temperature, relative humidity, wind direction, wind speed, atmospheric pressure and rainfall) were observed by the microenvironment platform on the roof of a high-rise dormitory building in the inner ring of Shanghai from January 14th, 2020 to February 18th, 2020. The characteristics and influencing factors of air pollutants before and after the implementation of the policy were analyzed through statistical analysis, synthetic analysis, Lagrangian particle dispersion model and Spearman correlation method, based on the above observation data in 2020 and the corresponding observation data in 2019, as well as the hourly monitoring data of gaseous pollutants (O3, NO2, CO, SO2) at Yangpu Sipiao air quality monitoring station. The results showed that:1) Changes in pollutant concentrations:the implementation of the policy reduced the magnitude of ρ(PM2.5), ρ(PM10) and ρ(NO2) significantly:ρ(PM2.5) and ρ(PM10) decreased from 61.4 μg/m3 to 38.1 μg/m3 and from 102.4 μg/m3 to 63.5 μg/m3, respectively, with a decrease rate of 38.0%, ρ(NO2) decreased from 57.3 μg/m3 to 27.0 μg/m3, with a decrease rate of 52.9%. ρ(O3) increased from 47.6 μg/m3 and 69.5 μg/m3. The diurnal bimodal and double-valley variation pattern of ρ(PM2.5) and ρ(PM10) became a single-valley pattern after the implementation of the policy; 2) The influence of meteorological factors:the anomaly of the southerly wind weakened the intensity of the winter monsoon, and the anomaly of the positive anomaly in the middle troposphere inhibited the development of convective activities, which easily led to the accumulation of atmospheric pollutants near the ground. ρ(PM2.5) and ρ(PM10) were negatively correlated with relative humidity. The influence of wind speed on ρ(PM2.5) and ρ(PM10) depended on the wind direction; 3) The impact of external sources:the urban agglomeration of the Yangtze River Delta and the surrounding provinces such as Shandong and Henan contributed significantly to ρ(PM2.5) and ρ(PM10) in Shanghai.
2021, 39(9): 117-122,175.
doi: 10.13205/j.hjgc.202109017
Abstract:
In this study, three carbon capture scenarios were designed, namely fixed quantity raw gas scenario, fixed carbon capture amount scenario, and mixed raw gas scenario. Cases reflecting different CO2 capture rates and product purity associated with different capture technologies were further designed under each scenario. The impacts of CO2 capture on the economic benefits of calorific value variation of blast furnace gas were analyzed. When the CO2 capture rate and CO2 product purity were equal, the calorific value of CO2 per unit based on the fixed quantity raw gas scenario was higher than that under the fixed carbon capture amount scenario. When the CO2 capture rate was fixed, with the reduction of CO2 product purity, the calorific value benefits of CO2 per unit mass based on the fixed quantity raw gas scenario and the fixed carbon capture amount scenario were both higher. When the purity of CO2 product was fixed, with the reduction of CO2 capture rate, the calorific value of fixed quantity raw gas scenario increased in efficiency, while the calorific value of the fixed carbon capture amount scenario decreased in efficiency.
In this study, three carbon capture scenarios were designed, namely fixed quantity raw gas scenario, fixed carbon capture amount scenario, and mixed raw gas scenario. Cases reflecting different CO2 capture rates and product purity associated with different capture technologies were further designed under each scenario. The impacts of CO2 capture on the economic benefits of calorific value variation of blast furnace gas were analyzed. When the CO2 capture rate and CO2 product purity were equal, the calorific value of CO2 per unit based on the fixed quantity raw gas scenario was higher than that under the fixed carbon capture amount scenario. When the CO2 capture rate was fixed, with the reduction of CO2 product purity, the calorific value benefits of CO2 per unit mass based on the fixed quantity raw gas scenario and the fixed carbon capture amount scenario were both higher. When the purity of CO2 product was fixed, with the reduction of CO2 capture rate, the calorific value of fixed quantity raw gas scenario increased in efficiency, while the calorific value of the fixed carbon capture amount scenario decreased in efficiency.
2021, 39(9): 123-130.
doi: 10.13205/j.hjgc.202109018
Abstract:
This study explored the methane production capacity of different source substrate systems from different residues of anaerobic fermentative hydrogen production using combined sludge and food waste through batch experiments, aimed to seek the optimum methane production conditions and the corresponding changes of the organic contents in the anaerobic system. The results showed that, the hydrogen production of substrate systems was positively correlated with the methane production performance, namely in the sequence of hydrogen production abound systi>hydrogen production deficient systi>non-hydrogen production system; when the inoculation amount increased, the methane production efficiency of the system was decreased, and the difference between the systems gradually got narrowed. Hydrogen production surplus system of 30% inoculation volume had the optimal methane production performance, and the average methane production rate was 0.54 mL/(g·d), reached 87.04% of methane concentration peak on the 27th day, and the highest accumulative methane yield was 1659 mL. It's mainly due to the large amount of TVFA degradation in this system (17565 mg COD/L), accounting for 50% of the degradation of TCOD (35384 mg/L).
This study explored the methane production capacity of different source substrate systems from different residues of anaerobic fermentative hydrogen production using combined sludge and food waste through batch experiments, aimed to seek the optimum methane production conditions and the corresponding changes of the organic contents in the anaerobic system. The results showed that, the hydrogen production of substrate systems was positively correlated with the methane production performance, namely in the sequence of hydrogen production abound systi>hydrogen production deficient systi>non-hydrogen production system; when the inoculation amount increased, the methane production efficiency of the system was decreased, and the difference between the systems gradually got narrowed. Hydrogen production surplus system of 30% inoculation volume had the optimal methane production performance, and the average methane production rate was 0.54 mL/(g·d), reached 87.04% of methane concentration peak on the 27th day, and the highest accumulative methane yield was 1659 mL. It's mainly due to the large amount of TVFA degradation in this system (17565 mg COD/L), accounting for 50% of the degradation of TCOD (35384 mg/L).
2021, 39(9): 131-137,186.
doi: 10.13205/j.hjgc.202109019
Abstract:
In order to study the effect of fly ash incorporation on the hydraulic characteristics of coal gangue, nine kinds of mixtures with different mixing ratio of fly ash and coal gangue were analyzed. The indoor one-dimensional fixed head method, a multi-fold pF Meter (DIK-3423) and a falling-pressure method was used to measure the volume of saturated water content, saturated hydraulic conductivity, the soil water characteristic curve(SWCC) and air permeability. The results indicated that:1) adding fly ash could increase the saturated water content of the mixtures, and the saturated water content of the mixture with mixing ratio of 3:7 was 36.9%~41.4%, the closest to the soil; 2) the saturated hydraulic conductivity of the mixture was affected by mixing ratio and bulk density. The saturated hydraulic conductivity decreased with the increase of bulk density, and also with the increase of fly ash's dosage in general. 3) the water retention capability of the mixture decreased with the increase of fly ash dosage. 4) the air permeability of the mixture decreased with the increase of fly ash's dosage. The air permeability of the mixture with fly ash incorporated below 40% had a changing tendency of small to large in sensitivity to water content, and mixture with other composition changed more uniformly. 5) the available water content of the mixture with the mixing ratio of 3:7~2:8 was 17.3%~17.6%, the closest to the soil; when the mixture was used to fill the collapsed land, the mixing ratio could be controlled at 3:7 to ensure suitable available water supply while the permeability was at a lower level. This study could provide data reference for improvement of land reclamation model in the subsidence areas.
In order to study the effect of fly ash incorporation on the hydraulic characteristics of coal gangue, nine kinds of mixtures with different mixing ratio of fly ash and coal gangue were analyzed. The indoor one-dimensional fixed head method, a multi-fold pF Meter (DIK-3423) and a falling-pressure method was used to measure the volume of saturated water content, saturated hydraulic conductivity, the soil water characteristic curve(SWCC) and air permeability. The results indicated that:1) adding fly ash could increase the saturated water content of the mixtures, and the saturated water content of the mixture with mixing ratio of 3:7 was 36.9%~41.4%, the closest to the soil; 2) the saturated hydraulic conductivity of the mixture was affected by mixing ratio and bulk density. The saturated hydraulic conductivity decreased with the increase of bulk density, and also with the increase of fly ash's dosage in general. 3) the water retention capability of the mixture decreased with the increase of fly ash dosage. 4) the air permeability of the mixture decreased with the increase of fly ash's dosage. The air permeability of the mixture with fly ash incorporated below 40% had a changing tendency of small to large in sensitivity to water content, and mixture with other composition changed more uniformly. 5) the available water content of the mixture with the mixing ratio of 3:7~2:8 was 17.3%~17.6%, the closest to the soil; when the mixture was used to fill the collapsed land, the mixing ratio could be controlled at 3:7 to ensure suitable available water supply while the permeability was at a lower level. This study could provide data reference for improvement of land reclamation model in the subsidence areas.
2021, 39(9): 138-145.
doi: 10.13205/j.hjgc.202109020
Abstract:
Anaerobic digestion is widely used in the recycling treatment of kitchen waste, urban organic waste and high-concentration wastewater. However, due to the accumulation of organic acids, inhibition of the produced ammonia nitrogen and high sensitivity of methanogenic bacteria to environmental factors, the digestion process is often unstable with low methane production rate in practical application. Biochar has the advantages of simple preparation, wide source of raw materials and low cost, and it can be added into the anaerobic digestion system to maintain the stable operation of the anaerobic digestion system and improve the efficiency of methane production. In this paper, the preparation methods, physical and chemical characteristics of biochar were introduced. Meanwhile, the effect and mechanism of biochar on anaerobic digestion were also reviewed based on the following aspects:enhancing buffering capacity of anaerobic digestion system, alleviating the inhibition of ammonia nitrogen through adsorbing the inhibitors, and serving as microbial carriers due to its abundant pores and large specific surface area.
Anaerobic digestion is widely used in the recycling treatment of kitchen waste, urban organic waste and high-concentration wastewater. However, due to the accumulation of organic acids, inhibition of the produced ammonia nitrogen and high sensitivity of methanogenic bacteria to environmental factors, the digestion process is often unstable with low methane production rate in practical application. Biochar has the advantages of simple preparation, wide source of raw materials and low cost, and it can be added into the anaerobic digestion system to maintain the stable operation of the anaerobic digestion system and improve the efficiency of methane production. In this paper, the preparation methods, physical and chemical characteristics of biochar were introduced. Meanwhile, the effect and mechanism of biochar on anaerobic digestion were also reviewed based on the following aspects:enhancing buffering capacity of anaerobic digestion system, alleviating the inhibition of ammonia nitrogen through adsorbing the inhibitors, and serving as microbial carriers due to its abundant pores and large specific surface area.
2021, 39(9): 146-153.
doi: 10.13205/j.hjgc.202109021
Abstract:
The detected ratea of emerging pollutants in sludge are increasing year by year, which brings potential safety hazard to sludge treatment. Sludge utilization (anaerobic digestion to biogas and aerobic composting to soil amendment) can not only realize the recycling of waste, but also effectively reduce the emerging pollutants in sludge. Therefore, this paper reviewed the occurrence of different emerging pollutants in sludge and the control measures of emerging pollutants in the process of sludge recycling. Sludge resource treatment process can effectively control and reduce the majority of emerging pollutants in the sludge. The removal efficiency of different emerging pollutants was mainly affected by the physical and chemical properties of the pollutants, degradation difficulty, temperature, pH, C/N and the addition of exogenous substances. It was proposed that the removal paths and degradation mechanism of multiple emerging pollutants coexistence system, optimization of the control parameters and rise of removal rate of emerging pollutants should be the technical breakthrough points in the future.
The detected ratea of emerging pollutants in sludge are increasing year by year, which brings potential safety hazard to sludge treatment. Sludge utilization (anaerobic digestion to biogas and aerobic composting to soil amendment) can not only realize the recycling of waste, but also effectively reduce the emerging pollutants in sludge. Therefore, this paper reviewed the occurrence of different emerging pollutants in sludge and the control measures of emerging pollutants in the process of sludge recycling. Sludge resource treatment process can effectively control and reduce the majority of emerging pollutants in the sludge. The removal efficiency of different emerging pollutants was mainly affected by the physical and chemical properties of the pollutants, degradation difficulty, temperature, pH, C/N and the addition of exogenous substances. It was proposed that the removal paths and degradation mechanism of multiple emerging pollutants coexistence system, optimization of the control parameters and rise of removal rate of emerging pollutants should be the technical breakthrough points in the future.
2021, 39(9): 154-159,192.
doi: 10.13205/j.hjgc.202109022
Abstract:
The lipids in the sludge can be extracted to produce biodiesel, and the ceramide can be chromatographed out of it, which are both important resource recovery methods. The residue remaining after the sludge is refined, can be prepared into biochar with adsorption effect by pyrolysis. In this study, the original sludge and degreasing sludge (the residue after Soxhlet extraction of the original sludge) were used to prepare biochar under anaerobic conditions at 500℃, 600℃, 700℃, and 800℃. They were characterized by scanning electron microscope (SEM), Fourier transform infrared (FT-IR), BET specific surface area analysis, to explore the regularity of biochar prepared by sludge changeing with temperature conditions. The study found that the microscopic surface of biochar prepared by degreasing sludge became rougher, the pore size increased, the specific surface area decreased, and the number of surface functional groups decreased, with the increase of temperature. Compared with the original sludge, the degreased sludge-based biochar showed weaker adsorption performance, but still had considerable value and application potential for further research.
The lipids in the sludge can be extracted to produce biodiesel, and the ceramide can be chromatographed out of it, which are both important resource recovery methods. The residue remaining after the sludge is refined, can be prepared into biochar with adsorption effect by pyrolysis. In this study, the original sludge and degreasing sludge (the residue after Soxhlet extraction of the original sludge) were used to prepare biochar under anaerobic conditions at 500℃, 600℃, 700℃, and 800℃. They were characterized by scanning electron microscope (SEM), Fourier transform infrared (FT-IR), BET specific surface area analysis, to explore the regularity of biochar prepared by sludge changeing with temperature conditions. The study found that the microscopic surface of biochar prepared by degreasing sludge became rougher, the pore size increased, the specific surface area decreased, and the number of surface functional groups decreased, with the increase of temperature. Compared with the original sludge, the degreased sludge-based biochar showed weaker adsorption performance, but still had considerable value and application potential for further research.
2021, 39(9): 160-168.
doi: 10.13205/j.hjgc.202109023
Abstract:
Waste activated sludge, granular sludge, distiller's yeast, and vinasse were inoculated in the food waste fermentation for organic acid production. Batch tests were conducted to compare the solubilization, hydrolysis, and acidification processes using four different inoculums during fermentation. Based on the batch test, we investigated the effect of different electron donors on chain elongation to produce caproate. When activated sludge was used as the inoculum of food waste fermentation, the production of L-lactic acid reached 22.2 g COD/L and its optical activity reached 82.3%. It was an effective way to ferment food waste to produce highly optically active L-lactic acid by inoculating activated sludge. Caproate at a concentration of 4.2 g COD/L was produced by inoculating granular sludge during fermentation, indicating the strong capacity of caproate production of granular sludge. When distiller's yeast and vinasse were used as the inoculum, high concentration of butyrate (21.6 g COD/L for distiller's yeast inoculum and 20.4 g COD/L for vinasse inoculum) was obtained, which was the key electron acceptor during chain elongation. The concentration of caproate reached 8.8 g COD/L by inoculating vinasse (lactic acid as the electron donor) and 10.4 g COD/L by inoculating distiller's yeast (ethanol as the electron donor). Microbial community analysis revealed that Streptococcus was the dominant genus, accounting for 80% and 55% by inoculating distiller's yeast and vinasse groups, respectively, showing a strong correlation with the production of high concentration caproate.
Waste activated sludge, granular sludge, distiller's yeast, and vinasse were inoculated in the food waste fermentation for organic acid production. Batch tests were conducted to compare the solubilization, hydrolysis, and acidification processes using four different inoculums during fermentation. Based on the batch test, we investigated the effect of different electron donors on chain elongation to produce caproate. When activated sludge was used as the inoculum of food waste fermentation, the production of L-lactic acid reached 22.2 g COD/L and its optical activity reached 82.3%. It was an effective way to ferment food waste to produce highly optically active L-lactic acid by inoculating activated sludge. Caproate at a concentration of 4.2 g COD/L was produced by inoculating granular sludge during fermentation, indicating the strong capacity of caproate production of granular sludge. When distiller's yeast and vinasse were used as the inoculum, high concentration of butyrate (21.6 g COD/L for distiller's yeast inoculum and 20.4 g COD/L for vinasse inoculum) was obtained, which was the key electron acceptor during chain elongation. The concentration of caproate reached 8.8 g COD/L by inoculating vinasse (lactic acid as the electron donor) and 10.4 g COD/L by inoculating distiller's yeast (ethanol as the electron donor). Microbial community analysis revealed that Streptococcus was the dominant genus, accounting for 80% and 55% by inoculating distiller's yeast and vinasse groups, respectively, showing a strong correlation with the production of high concentration caproate.
2021, 39(9): 169-175.
doi: 10.13205/j.hjgc.202109024
Abstract:
In recent years, harmless and resource utilization of food waste are advocated researching and developing directions, which also play important role in public health and sustainable development. This paper selected two food waste treatment plants in Tangshan and Xiamen for investigation, representing two typical food waste treatment modes in China. The characterization, standardization, and normalization were conducted by method IMPACT2002+ in Simapro software. In addition, their economic benefits were briefly evaluated. The results demonstrated that case 1(Tangshan) dominated the environmental impact results of 13 midpoint indicators, such as aquatic ecotoxicity, non-renewable resources, and terrestrial ecotoxicity. The total potential environmental impacts of co-production of case 1(Tangshan) and case 2(Xiamen) were -26mpt and 22.7mpt, respectively. Thus, the environmental benefits of case 1 predominated. Comparing to case1, case2 has a shorter payback period and better economic benefits.
In recent years, harmless and resource utilization of food waste are advocated researching and developing directions, which also play important role in public health and sustainable development. This paper selected two food waste treatment plants in Tangshan and Xiamen for investigation, representing two typical food waste treatment modes in China. The characterization, standardization, and normalization were conducted by method IMPACT2002+ in Simapro software. In addition, their economic benefits were briefly evaluated. The results demonstrated that case 1(Tangshan) dominated the environmental impact results of 13 midpoint indicators, such as aquatic ecotoxicity, non-renewable resources, and terrestrial ecotoxicity. The total potential environmental impacts of co-production of case 1(Tangshan) and case 2(Xiamen) were -26mpt and 22.7mpt, respectively. Thus, the environmental benefits of case 1 predominated. Comparing to case1, case2 has a shorter payback period and better economic benefits.
2021, 39(9): 176-186.
doi: 10.13205/j.hjgc.202109025
Abstract:
As an environmentally friendly technology, composting can transform waste organic matter into macromolecular humic-like substance which has variety of functional groups by biotransformation. And these products are beneficial to soil remediation and soil quality improvement, and complete return of organic matter from soil to soil, and can effectively solve the main contradictions, such as overloading of cultivated land and soil contamination in China. In this paper, the recent study in the soil remediation and quality improvement of compost were reviewed. The remediation of common contaminated soils (such as heavy metal contaminated soil, saline soil, organochlorine pesticide contamination soil), the quality improvement of soil carbon pool, and the global carbon cycle were discussed in detail. The future for development of compost was prospected, and expected to provide an effective reference for future research on the whole chain of organic waste treatment-engineering application of humic-like acids substance-soil remediation and quality improvement, and to help improve the theoretical basis and practical applications of soil remediation and quality improvement.
As an environmentally friendly technology, composting can transform waste organic matter into macromolecular humic-like substance which has variety of functional groups by biotransformation. And these products are beneficial to soil remediation and soil quality improvement, and complete return of organic matter from soil to soil, and can effectively solve the main contradictions, such as overloading of cultivated land and soil contamination in China. In this paper, the recent study in the soil remediation and quality improvement of compost were reviewed. The remediation of common contaminated soils (such as heavy metal contaminated soil, saline soil, organochlorine pesticide contamination soil), the quality improvement of soil carbon pool, and the global carbon cycle were discussed in detail. The future for development of compost was prospected, and expected to provide an effective reference for future research on the whole chain of organic waste treatment-engineering application of humic-like acids substance-soil remediation and quality improvement, and to help improve the theoretical basis and practical applications of soil remediation and quality improvement.
2021, 39(9): 187-192.
doi: 10.13205/j.hjgc.202109026
Abstract:
Volatile fatty acids (VFAs), produced by co-anaerobic fermentation food waste and sewage sludge, have widely economic and practical value. This study investigated the effects of different food waste ratios of food waste-sewage sludge (control, 0%, 5% and 10%) for co-anaerobic fermentation of food waste and sewage sludge on the production of VFAs with 1 Volt electrochemical pretreatment. The results showed that under the electrochemical pretreatment, the concentration of soluble COD increased rapidly up to 969~1266 mg/L with the food waste ratios increased from 0% to 10%, and then it was converted to VFAs. Especially, the highest VFAs production achieved at 132.2 mg/L within 15 days when the food waste ratio accounting for 10% of food waste-sewage sludge. This study proved that 1 Volt electrochemical pretreatment could improve the characteristics of food waste-sewage sludge and accelerate their co-anaerobic fermentation. At the same time, food waste addition could increase the content of organic matters in sewage sludge, which further increased the VFAs production to realize the resource utilization.
Volatile fatty acids (VFAs), produced by co-anaerobic fermentation food waste and sewage sludge, have widely economic and practical value. This study investigated the effects of different food waste ratios of food waste-sewage sludge (control, 0%, 5% and 10%) for co-anaerobic fermentation of food waste and sewage sludge on the production of VFAs with 1 Volt electrochemical pretreatment. The results showed that under the electrochemical pretreatment, the concentration of soluble COD increased rapidly up to 969~1266 mg/L with the food waste ratios increased from 0% to 10%, and then it was converted to VFAs. Especially, the highest VFAs production achieved at 132.2 mg/L within 15 days when the food waste ratio accounting for 10% of food waste-sewage sludge. This study proved that 1 Volt electrochemical pretreatment could improve the characteristics of food waste-sewage sludge and accelerate their co-anaerobic fermentation. At the same time, food waste addition could increase the content of organic matters in sewage sludge, which further increased the VFAs production to realize the resource utilization.
2021, 39(9): 193-198.
doi: 10.13205/j.hjgc.202109027
Abstract:
With magnesium chloride as the additive, the artificial struvite was prepared when the ratio of n(Mg2+):n(NH4+):n(PO43-) in N and P wastewater was adjusted to be 1.15:1:1, pH was between 8.5 and 9, and the reaction time was 30 min. The product was characterized by SEM, FT-IR and XRD, indicating that struvite was the main content. Artificial struvite combined with ryegrass was used to remediation soil contaminated by Cd. Studies showed that artificial struvite could effectively improve the soil pH, available phosphorus content and enzyme activity to increase soil environmental quality. At the same time, it could reduce the exchangable Cd content in the soil and increase the GSH content in the ryegrass leaves to reduce the MDA content in the leaves and reduce the degree of membrane lipid peroxidation. Compared with the control, the biomass of ryegrass was increased by 81.7%~148.5%, and the total extraction of Cd was increased by 25.41%~44.27%. The remediation efficiency was the best when the additive dosage was 5%.
With magnesium chloride as the additive, the artificial struvite was prepared when the ratio of n(Mg2+):n(NH4+):n(PO43-) in N and P wastewater was adjusted to be 1.15:1:1, pH was between 8.5 and 9, and the reaction time was 30 min. The product was characterized by SEM, FT-IR and XRD, indicating that struvite was the main content. Artificial struvite combined with ryegrass was used to remediation soil contaminated by Cd. Studies showed that artificial struvite could effectively improve the soil pH, available phosphorus content and enzyme activity to increase soil environmental quality. At the same time, it could reduce the exchangable Cd content in the soil and increase the GSH content in the ryegrass leaves to reduce the MDA content in the leaves and reduce the degree of membrane lipid peroxidation. Compared with the control, the biomass of ryegrass was increased by 81.7%~148.5%, and the total extraction of Cd was increased by 25.41%~44.27%. The remediation efficiency was the best when the additive dosage was 5%.
2021, 39(9): 199-204.
doi: 10.13205/j.hjgc.202109028
Abstract:
Soil bioremediation technology has become a research hotspot in the world because of its low cost and no secondary pollution. The article applied bibliometric methods to analyze the research status and development direction in the field of soil bioremediation, and provided reference for subsequent research. A statistical analysis was carried out based on 25174 papers on soil bioremediation included in the core database of Web of Science from 2000 to 2019. The results showed that although China started late in this field, it developed rapidly and became the country with the highest number of publications (3680). Among the publishing organizations, the Chinese Academy of Sciences had the highest number of publications and citation. Chemosphere was the journal with the most publications in this field (963). The journal Science of the Total Environment developed the fastest in recent years; the latest research hotspots in soil bioremediation were focused on microbial communities, gene sequencing, metabolic pathway analysis, and new materials innovation.
Soil bioremediation technology has become a research hotspot in the world because of its low cost and no secondary pollution. The article applied bibliometric methods to analyze the research status and development direction in the field of soil bioremediation, and provided reference for subsequent research. A statistical analysis was carried out based on 25174 papers on soil bioremediation included in the core database of Web of Science from 2000 to 2019. The results showed that although China started late in this field, it developed rapidly and became the country with the highest number of publications (3680). Among the publishing organizations, the Chinese Academy of Sciences had the highest number of publications and citation. Chemosphere was the journal with the most publications in this field (963). The journal Science of the Total Environment developed the fastest in recent years; the latest research hotspots in soil bioremediation were focused on microbial communities, gene sequencing, metabolic pathway analysis, and new materials innovation.
2021, 39(9): 205-210,216.
doi: 10.13205/j.hjgc.202109029
Abstract:
Through indoor simulation experiments, the effect of biosynthetic manganese oxide (Bio-MnOx) material on the stabilization of arsenic (As) in contaminated soil was studied. The results showed that:1) the addition of Bio-MnOx could effectively decrease the leaching amount of As, in which the water-soluble As content decreased from 2.28 mg/kg to 0.86 mg/kg, with a reduction efficiency of 62.3%; 2) the five-step continuous extraction results showed that the content of water-soluble As and surface-adsorbed fraction decreased significantly after Bio-MnOx treatment; 3) the environmental risk analysis further confirmed that the risk of As decreased significantly after Bio-MnOx treatment; 4) bacterial biodiversity analysis based on 16s RNA indicated that the richness of soil microbial diversity increased significantly after Bio-MnOx treatment; 5) the analysis of microbial community structure showed that the dominant bacterial community structure changed from Bacillus to Clostridium, Comamonas, and Clostridium sensu tricto at the genus level. In general, Bio-MnOx could be used as an effective biogenic material to stabilize As in soils.
Through indoor simulation experiments, the effect of biosynthetic manganese oxide (Bio-MnOx) material on the stabilization of arsenic (As) in contaminated soil was studied. The results showed that:1) the addition of Bio-MnOx could effectively decrease the leaching amount of As, in which the water-soluble As content decreased from 2.28 mg/kg to 0.86 mg/kg, with a reduction efficiency of 62.3%; 2) the five-step continuous extraction results showed that the content of water-soluble As and surface-adsorbed fraction decreased significantly after Bio-MnOx treatment; 3) the environmental risk analysis further confirmed that the risk of As decreased significantly after Bio-MnOx treatment; 4) bacterial biodiversity analysis based on 16s RNA indicated that the richness of soil microbial diversity increased significantly after Bio-MnOx treatment; 5) the analysis of microbial community structure showed that the dominant bacterial community structure changed from Bacillus to Clostridium, Comamonas, and Clostridium sensu tricto at the genus level. In general, Bio-MnOx could be used as an effective biogenic material to stabilize As in soils.
2021, 39(9): 211-216.
doi: 10.13205/j.hjgc.202109030
Abstract:
In order to ensure the quality and safety of agricultural products from the source and repair cadmium pollution in farmland soil, field experiments were carried out on cadmium contaminated farmland soil. The effects of applying five different passivators such as TX,NL soil conditioner, biochar, lime and silicon fertilizer on soil pH, organic matter, available state content of Cd and different forms of Cd were studied, and the effects of the passivators on the yield of four different rice varieties and Cd accumulation in rice organs were discussed. The results showed that compared with the control, after the application of TX, NL soil conditioner, biochar, lime and silicon fertilizer, the available Cd content in soil was decreased by 59.4%, 29.9%, 22.8%, 22.4% and 54.4% respectively. Applying passivator could improve rice yield and inhibit accumulation of Cd in rice organs. When rice variaties of Huaidao 5 or Yangjing 805 treated together with TX soil conditioner, the grain Cd content was 0.163 mg/kg or 0.147 mg/kg, respectively, which achieved the safety and quality standard of agricultural products (China's national standard, GB 2762-2017). The results indicated that two rice varieties of Huaidao 5 and Yangjing 805 were more preferable for low accumulation of Cd in the middle area of Jiangsu, and for planting in moderately Cd polluted soil, in combination with application of appropriate passivators.
In order to ensure the quality and safety of agricultural products from the source and repair cadmium pollution in farmland soil, field experiments were carried out on cadmium contaminated farmland soil. The effects of applying five different passivators such as TX,NL soil conditioner, biochar, lime and silicon fertilizer on soil pH, organic matter, available state content of Cd and different forms of Cd were studied, and the effects of the passivators on the yield of four different rice varieties and Cd accumulation in rice organs were discussed. The results showed that compared with the control, after the application of TX, NL soil conditioner, biochar, lime and silicon fertilizer, the available Cd content in soil was decreased by 59.4%, 29.9%, 22.8%, 22.4% and 54.4% respectively. Applying passivator could improve rice yield and inhibit accumulation of Cd in rice organs. When rice variaties of Huaidao 5 or Yangjing 805 treated together with TX soil conditioner, the grain Cd content was 0.163 mg/kg or 0.147 mg/kg, respectively, which achieved the safety and quality standard of agricultural products (China's national standard, GB 2762-2017). The results indicated that two rice varieties of Huaidao 5 and Yangjing 805 were more preferable for low accumulation of Cd in the middle area of Jiangsu, and for planting in moderately Cd polluted soil, in combination with application of appropriate passivators.
