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2021 Vol. 39, No. 1
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2021, 39(1): 1-17.
doi: 10.13205/j.hjgc.202101001
Abstract:
Straw biomass, as a clean energy alternative to fossil fuels, is of great significance to environmental protection and energy structure transformation. China has abundant crop yield and great potential in the comprehensive utilization of straw. In terms of the whole straw energy industry, China is in the stage of orderly promotion, but there is a gap between the domestic core technology and equipment level and the international advanced level, the industrial benefits are still not ideal, and enterprises have a strong dependence on government financial subsidies. For straw ethanol technology, the straw biogas technology, straw pyrolysis technology and straw curing technology, on the basis of fully understanding of the straw utilization in China, straw energy technology and the application progress at home and abroad were discussed, and the reduction of fermentation inhibiting, the optimization of anaerobic digestion performance degradation, the development of pyrolytic carbon potential, the activation of molding fuel stick performance and other technical issues were discussed. Based on the economic analysis, some means to improve the efficiency of energy technologies were put forward, such as whole-component utilization, combined production mode of gas and fertilizer, cascade utilization of bulk products, and the effects of policy subsidies and technology upgrading on the enterprise's efficiency were compared. Finally, some suggestions on the development direction of straw industry from the perspective of policy and new technology were put forward.
Straw biomass, as a clean energy alternative to fossil fuels, is of great significance to environmental protection and energy structure transformation. China has abundant crop yield and great potential in the comprehensive utilization of straw. In terms of the whole straw energy industry, China is in the stage of orderly promotion, but there is a gap between the domestic core technology and equipment level and the international advanced level, the industrial benefits are still not ideal, and enterprises have a strong dependence on government financial subsidies. For straw ethanol technology, the straw biogas technology, straw pyrolysis technology and straw curing technology, on the basis of fully understanding of the straw utilization in China, straw energy technology and the application progress at home and abroad were discussed, and the reduction of fermentation inhibiting, the optimization of anaerobic digestion performance degradation, the development of pyrolytic carbon potential, the activation of molding fuel stick performance and other technical issues were discussed. Based on the economic analysis, some means to improve the efficiency of energy technologies were put forward, such as whole-component utilization, combined production mode of gas and fertilizer, cascade utilization of bulk products, and the effects of policy subsidies and technology upgrading on the enterprise's efficiency were compared. Finally, some suggestions on the development direction of straw industry from the perspective of policy and new technology were put forward.
2021, 39(1): 18-23.
doi: 10.13205/j.hjgc.202101002
Abstract:
Considering the economic conditions in rural areas,the air hoist was used to replace the traditional reflux pump,and the air lifting A2/O integrated device was used to analyze the nitrogen and phosphorus removal of rural domestic sewage. Under the condition of high DO reflux liquid promoted by air, the effects of different reflux ratio of nitrifying liquid and DO concentration in aeration tank on sewage purification effect were investigated. The results showed that controlling sludge reflux ratio was 70%,HRT was 12 h,sludge age was 15 d. With aims of energy saving, consumption reduction and pollutant purification performance considered comprehensively, it was found out that the optimized condition was the reflux ratio of nitrifying liquid of 200% and DO of 2.0 mg/L.
Considering the economic conditions in rural areas,the air hoist was used to replace the traditional reflux pump,and the air lifting A2/O integrated device was used to analyze the nitrogen and phosphorus removal of rural domestic sewage. Under the condition of high DO reflux liquid promoted by air, the effects of different reflux ratio of nitrifying liquid and DO concentration in aeration tank on sewage purification effect were investigated. The results showed that controlling sludge reflux ratio was 70%,HRT was 12 h,sludge age was 15 d. With aims of energy saving, consumption reduction and pollutant purification performance considered comprehensively, it was found out that the optimized condition was the reflux ratio of nitrifying liquid of 200% and DO of 2.0 mg/L.
2021, 39(1): 24-32,39.
doi: 10.13205/j.hjgc.202101003
Abstract:
Many problems still exist, such as low efficiency, long cycles, and easy recurrence for treatment of black-odor water. Further improving the purification efficiency of black-odor water by combinatorial biotechnology has become an urgent problem. Therefore, in this study, the purification efficiency of black-odor water by different bio-promoter, aeration methods, fillers, and plants was compared and analyzed by single factor and orthogonal experiments, and the reasons for the differences in purification efficiency under different conditions were revealed by high-throughput sequencing technique from the perspective of microorganisms. The results showed that there were differences in the purification efficiency of black-odor water under different conditions. Among them, the biological purification enhancer (BE), continuous aeration, elastic three-dimensional filler and water peanut were better in terms of purification capacity, and the dominant phyla, dominant bacteria. And their relative abundance were different in each experimental group. This showed that the differences in the composition of microbial community structure maybe the reason for the difference in purification efficiency of black-odor water under different conditions. Continuous aeration stimulated a large number of aerobic and facultative bacteria; the biofilm growing on the surface of the elastic three-dimensional filler provided necessary conditions for the growth of aerobic bacteria, anaerobic bacteria, and facultative bacteria, especially for the latter two, and stimulated the large-scale growth and reproduction of anaerobic bacteria and facultative bacteria; water peanut also had its unique rhizosphere microbial community structure that was conducive to pollutant purification. The results of this study could provide a reference for selecting efficient condition parameters for combinatorial biotechnology, and a theoretical basis for efficiently purifying black-odor water by the enhanced combinatorial biotechnology.
Many problems still exist, such as low efficiency, long cycles, and easy recurrence for treatment of black-odor water. Further improving the purification efficiency of black-odor water by combinatorial biotechnology has become an urgent problem. Therefore, in this study, the purification efficiency of black-odor water by different bio-promoter, aeration methods, fillers, and plants was compared and analyzed by single factor and orthogonal experiments, and the reasons for the differences in purification efficiency under different conditions were revealed by high-throughput sequencing technique from the perspective of microorganisms. The results showed that there were differences in the purification efficiency of black-odor water under different conditions. Among them, the biological purification enhancer (BE), continuous aeration, elastic three-dimensional filler and water peanut were better in terms of purification capacity, and the dominant phyla, dominant bacteria. And their relative abundance were different in each experimental group. This showed that the differences in the composition of microbial community structure maybe the reason for the difference in purification efficiency of black-odor water under different conditions. Continuous aeration stimulated a large number of aerobic and facultative bacteria; the biofilm growing on the surface of the elastic three-dimensional filler provided necessary conditions for the growth of aerobic bacteria, anaerobic bacteria, and facultative bacteria, especially for the latter two, and stimulated the large-scale growth and reproduction of anaerobic bacteria and facultative bacteria; water peanut also had its unique rhizosphere microbial community structure that was conducive to pollutant purification. The results of this study could provide a reference for selecting efficient condition parameters for combinatorial biotechnology, and a theoretical basis for efficiently purifying black-odor water by the enhanced combinatorial biotechnology.
2021, 39(1): 33-39.
doi: 10.13205/j.hjgc.202101004
Abstract:
An electricity-producing strain XMS-1 was screened from sediments in the Xiamen Bay, and its related characteristics and application in environmental pollution control were analyzed. According to the morphological, biochemical properties of the strain and the results of 16S rRNA gene sequencing, the species and genera of the strain were determined. The electricity production performance of the strain was studied by constructing microbial fuel cell. At the same time, the reduction ability of hexavalent chromium, a typical heavy metal pollutant, was also explored. The bacterium was identify as Shewanella. When the initial inoculation concentration in MFC was OD600=0.3, the maximum power density was 18 mW/m2 and the current density was 243 mA/m2. The bacterium could reduce Cr(Ⅵ) at pH of 7~8, and NaCl concentration of 0~6%. And this bacterium was proved to be capable of reducing Cr(Ⅵ) under the condition of wide pH and high salinity, and had good electricity production capacity. The bacterium XMS-1 had good potential in practical industrial wastewater treatment and provided scientific basis for seawater reclamation.
An electricity-producing strain XMS-1 was screened from sediments in the Xiamen Bay, and its related characteristics and application in environmental pollution control were analyzed. According to the morphological, biochemical properties of the strain and the results of 16S rRNA gene sequencing, the species and genera of the strain were determined. The electricity production performance of the strain was studied by constructing microbial fuel cell. At the same time, the reduction ability of hexavalent chromium, a typical heavy metal pollutant, was also explored. The bacterium was identify as Shewanella. When the initial inoculation concentration in MFC was OD600=0.3, the maximum power density was 18 mW/m2 and the current density was 243 mA/m2. The bacterium could reduce Cr(Ⅵ) at pH of 7~8, and NaCl concentration of 0~6%. And this bacterium was proved to be capable of reducing Cr(Ⅵ) under the condition of wide pH and high salinity, and had good electricity production capacity. The bacterium XMS-1 had good potential in practical industrial wastewater treatment and provided scientific basis for seawater reclamation.
2021, 39(1): 40-46.
doi: 10.13205/j.hjgc.202101005
Abstract:
The adsorption kinetics, thermodynamics experiments and adsorption isothermal models of adsorption of adenosine monophosphate(AMP) on aluminum-based water treatment residual (Al-WTR) were studied by batch test. The effects of initial phosphorus concentration, temperature and particle size on the adsorption of AMP were analyzed. The experimental results showed that AMP uptake was favored under neutral and acidic conditions. The smaller the particle size, the larger the adsorption amount. The Al-WTR with size of 1.0~2.0 mm was most suitable for practical application. The pseudo-second-order kinetic model well fitted the adsorption process of Al-AMP on WTR, which indicated that the adsorption was mainly based on chemical adsorption. The Langmuir isotherm model described the adsorption equilibrium well, and the thermodynamic analysis manifested that the adsorption process was a spontaneous, endothermic and entropy-increasing process. The analysis of Fourier-transform infrared spectrum analysis (FTIR) showed that there was a loss of hydroxy groups associated with Al and an increase in Al-O-P bonds during the adsorption of AMP on Al-WTR. This phenomenon was enhanced by the increase of initial phosphorus concentration, indicating that the adsorption of Al-WTR on AMP mainly fulfilled through ligand exchange.
The adsorption kinetics, thermodynamics experiments and adsorption isothermal models of adsorption of adenosine monophosphate(AMP) on aluminum-based water treatment residual (Al-WTR) were studied by batch test. The effects of initial phosphorus concentration, temperature and particle size on the adsorption of AMP were analyzed. The experimental results showed that AMP uptake was favored under neutral and acidic conditions. The smaller the particle size, the larger the adsorption amount. The Al-WTR with size of 1.0~2.0 mm was most suitable for practical application. The pseudo-second-order kinetic model well fitted the adsorption process of Al-AMP on WTR, which indicated that the adsorption was mainly based on chemical adsorption. The Langmuir isotherm model described the adsorption equilibrium well, and the thermodynamic analysis manifested that the adsorption process was a spontaneous, endothermic and entropy-increasing process. The analysis of Fourier-transform infrared spectrum analysis (FTIR) showed that there was a loss of hydroxy groups associated with Al and an increase in Al-O-P bonds during the adsorption of AMP on Al-WTR. This phenomenon was enhanced by the increase of initial phosphorus concentration, indicating that the adsorption of Al-WTR on AMP mainly fulfilled through ligand exchange.
2021, 39(1): 47-50,147.
doi: 10.13205/j.hjgc.202101006
Abstract:
In order to explore the through-flow characteristics of gravel filter bed (GFB) in river water restoration, a river ecological restoration project in Hanzhong, Shaanxi Province, was taken as an objective case, and the hydrodynamic model of the river was constructed by using MIKE 21 software. By simulating the flow conditions of the main channel and GFB under the designed flow rate, the velocity and water level distribution of the channel were obtained, and the flow characteristics of gravel filter bed were calculated. The results showed that according to the distribution of flow, the water flow that entered GFB only accounted for (1.00±0.25)% of the designed flow in the river. Therefore, GFB played a limited role in river water restoration in practice. The study suggested that GFB built in a real river channel was a complex system with bypass system. So, hydraulic retention time, flow times of filter bed and flow capacity of river channel should be considered comprehensively in design, which had certain significance for the similar project cases.
In order to explore the through-flow characteristics of gravel filter bed (GFB) in river water restoration, a river ecological restoration project in Hanzhong, Shaanxi Province, was taken as an objective case, and the hydrodynamic model of the river was constructed by using MIKE 21 software. By simulating the flow conditions of the main channel and GFB under the designed flow rate, the velocity and water level distribution of the channel were obtained, and the flow characteristics of gravel filter bed were calculated. The results showed that according to the distribution of flow, the water flow that entered GFB only accounted for (1.00±0.25)% of the designed flow in the river. Therefore, GFB played a limited role in river water restoration in practice. The study suggested that GFB built in a real river channel was a complex system with bypass system. So, hydraulic retention time, flow times of filter bed and flow capacity of river channel should be considered comprehensively in design, which had certain significance for the similar project cases.
2021, 39(1): 51-57,17.
doi: 10.13205/j.hjgc.202101007
Abstract:
In this study, simultaneous partial nitrification and denitrification (SPND) process was successfully established for the treatment of high-salinity wastewater in a hybrid sequencing batch biofilm reactor (HSBBR). The effect of operational mode on the reactor performance and microbial community was investigated. When the reactor was operated in alternating anoxic/aerobic mode (anoxic/aerobic hour ratio was 2.0 h/4.5 h), the removal efficiencies of NH4+-N, total inorganic nitrogen (TIN) and COD were 95.00%, 84.83% and 86.72%, respectively, and the effluent contained nitrite and nitrate. When operational mode was switched to fully aerobic mode (anoxic/aerobic hour ratio was 0.0/6.5 h), removal efficiencies of NH3-N, TIN and COD increased to 100.00%, 85.94% and 89.46%, and nitrate was the only nitrogen component in the effluent. The high-throughput sequencing results showed that the dominant phyla were Proteobacteria and Bacteroidetes in both suspended sludge (S-sludge) and biofilm in two modes. Genus Nitrosomonas was the only ammonia-oxidizing bacteria (AOB) detected in this study and appeared higher relative abundance in S-sludge and biofilm samples in the fully aerobic mode compared to the alternating anoxic/aerobic mode. S-sludge and biofilm shared similar dominant denitrifying bacteria (DNB), including genera Candidatus_Competibacter, Paracoccus, Thauera and Denittrasoma. The relative abundance of Candidatus_Competibacter and Thauera decreased in fully aerobic mode, while Paracoccus and Denitratisoma showed increasing tendency. Multiple DNB genera accompanied by AOB contributed to the efficient nitrogen removal via SPND process.
In this study, simultaneous partial nitrification and denitrification (SPND) process was successfully established for the treatment of high-salinity wastewater in a hybrid sequencing batch biofilm reactor (HSBBR). The effect of operational mode on the reactor performance and microbial community was investigated. When the reactor was operated in alternating anoxic/aerobic mode (anoxic/aerobic hour ratio was 2.0 h/4.5 h), the removal efficiencies of NH4+-N, total inorganic nitrogen (TIN) and COD were 95.00%, 84.83% and 86.72%, respectively, and the effluent contained nitrite and nitrate. When operational mode was switched to fully aerobic mode (anoxic/aerobic hour ratio was 0.0/6.5 h), removal efficiencies of NH3-N, TIN and COD increased to 100.00%, 85.94% and 89.46%, and nitrate was the only nitrogen component in the effluent. The high-throughput sequencing results showed that the dominant phyla were Proteobacteria and Bacteroidetes in both suspended sludge (S-sludge) and biofilm in two modes. Genus Nitrosomonas was the only ammonia-oxidizing bacteria (AOB) detected in this study and appeared higher relative abundance in S-sludge and biofilm samples in the fully aerobic mode compared to the alternating anoxic/aerobic mode. S-sludge and biofilm shared similar dominant denitrifying bacteria (DNB), including genera Candidatus_Competibacter, Paracoccus, Thauera and Denittrasoma. The relative abundance of Candidatus_Competibacter and Thauera decreased in fully aerobic mode, while Paracoccus and Denitratisoma showed increasing tendency. Multiple DNB genera accompanied by AOB contributed to the efficient nitrogen removal via SPND process.
2021, 39(1): 58-63.
doi: 10.13205/j.hjgc.202101008
Abstract:
In view of the current hot spots of rural domestic sewage treatment, the effect of applying autonomous breathing ecological filter technology to treat rural domestic sewage under pilot scale test conditions was studied. The results showed that the technology had a good removal effect on COD, TN, NH3-N, TP and SS, and their average removal rates were (79.22±4.28)%, (66.13±6.58)%, (84.25±4.87)%,(94.23±0.67)% and (89.07±1.35)%, respectively. The main indicators could stably reach the class A standard of Discharge Standard of Pollutants for Urban Sewage Treatment Plants (GB 18918-2002). The process design of layered packing, autonomous breathing system and intermittent operation mode were coupled with each other, and eventualy improve the treatment effect of the system.
In view of the current hot spots of rural domestic sewage treatment, the effect of applying autonomous breathing ecological filter technology to treat rural domestic sewage under pilot scale test conditions was studied. The results showed that the technology had a good removal effect on COD, TN, NH3-N, TP and SS, and their average removal rates were (79.22±4.28)%, (66.13±6.58)%, (84.25±4.87)%,(94.23±0.67)% and (89.07±1.35)%, respectively. The main indicators could stably reach the class A standard of Discharge Standard of Pollutants for Urban Sewage Treatment Plants (GB 18918-2002). The process design of layered packing, autonomous breathing system and intermittent operation mode were coupled with each other, and eventualy improve the treatment effect of the system.
2021, 39(1): 64-69.
doi: 10.13205/j.hjgc.202101009
Abstract:
To study the characteristics of water environment changes in different tail water receiving rivers, 33 samples were collected from 4 groups of the rivers, and five indicators, CODMn, TN, TP, NH3-N and Chl-a, were determined. Combined with high-throughput sequencing, the water quality changes, eutrophication characteristics and bacterial community structure were analyzed along the distance. Results showed that:the change of pollutant concentration caused by tailwater would recover to background value within 50~100 m except TN. The supplement of tailwater increased the bacterial richness and diversity, but the proportion of dominant species decreased and their relative abundance changed. After 50~100 m, the proportion began to increase and Proteobacteria became the absolute dominant phylum. At the level of genus, the relative abundance of dominant bacteria in background section all decreased with supplement of tailwater, while the abundance of Rhodovulum, Pseudoalteromonas, Massilia were significantly negative correlated to river eutrophication index (P<0.05). When the discharge ratio was ≥ 50%, the similarity of bacterial community structure between downstream and tailwater outlet was higher. In addition, tailwater may bring a large number of other microbial species, causing an increase in ecological risk of river.
To study the characteristics of water environment changes in different tail water receiving rivers, 33 samples were collected from 4 groups of the rivers, and five indicators, CODMn, TN, TP, NH3-N and Chl-a, were determined. Combined with high-throughput sequencing, the water quality changes, eutrophication characteristics and bacterial community structure were analyzed along the distance. Results showed that:the change of pollutant concentration caused by tailwater would recover to background value within 50~100 m except TN. The supplement of tailwater increased the bacterial richness and diversity, but the proportion of dominant species decreased and their relative abundance changed. After 50~100 m, the proportion began to increase and Proteobacteria became the absolute dominant phylum. At the level of genus, the relative abundance of dominant bacteria in background section all decreased with supplement of tailwater, while the abundance of Rhodovulum, Pseudoalteromonas, Massilia were significantly negative correlated to river eutrophication index (P<0.05). When the discharge ratio was ≥ 50%, the similarity of bacterial community structure between downstream and tailwater outlet was higher. In addition, tailwater may bring a large number of other microbial species, causing an increase in ecological risk of river.
2021, 39(1): 70-74,165.
doi: 10.13205/j.hjgc.202101010
Abstract:
In order to solve the problem of high nitrate content in secondary effluent of municipal wastewater treatment plants, the sygergistic effect of Pd-Cu/graphene and zero-valent iron (Fe0) on nitrate removal was investigated. The research on condition optimization of catalytic denitrification was conducted. Results showed that good catalytic performance was obtained under the following conditions:Fe0 4 g/L, Pd:Cu 3:1, pH 4.2, Pd-Cu/graphene 4 g/L, and reaction time 2 h, with the 78% of nitrate removal rate and 74% of N2 conversion rate. In catalytic denitrification process, Fe0, as the electron donor, mainly contributed to triggering the catalytic reaction, which occurred in the activated sites (Pd and Cu). The nitrate could be removed and converted to N2 through deoxidization reaction under the effect of the catalyst. Additionally, the carrier and the mass transfer process were also the important factors that may greatly influence the catalytic performance.
In order to solve the problem of high nitrate content in secondary effluent of municipal wastewater treatment plants, the sygergistic effect of Pd-Cu/graphene and zero-valent iron (Fe0) on nitrate removal was investigated. The research on condition optimization of catalytic denitrification was conducted. Results showed that good catalytic performance was obtained under the following conditions:Fe0 4 g/L, Pd:Cu 3:1, pH 4.2, Pd-Cu/graphene 4 g/L, and reaction time 2 h, with the 78% of nitrate removal rate and 74% of N2 conversion rate. In catalytic denitrification process, Fe0, as the electron donor, mainly contributed to triggering the catalytic reaction, which occurred in the activated sites (Pd and Cu). The nitrate could be removed and converted to N2 through deoxidization reaction under the effect of the catalyst. Additionally, the carrier and the mass transfer process were also the important factors that may greatly influence the catalytic performance.
2021, 39(1): 75-79,129.
doi: 10.13205/j.hjgc.202101011
Abstract:
In this paper, a mathematical model was set up, taking the Fushun West Open-pit mine as the research area, using the GMS (groundwater modeling system) numerical simulation software, based on the analysis of the mining area and its surrounding area, geological and hydrogeological conditions, as well as the characteristics of the formation lithology and geological structure. Based on the geological exploration data of the working area and the analysis of water filling factors, a hydrogeological model was established to predict the water inflow, and the layout scheme of drainage well in equilibrium state was put forward. The results showed that according to the topographic characteristics of the mine, when five horizontal wells with depth of 100 m, length of 100 m and displacement volume of 10~20 m3/d were placed on the north and south sides of the mine, and four shafts with depth of 70~100 m and displacement volume of 20 m3/d were placed at the bottom of the mine according to the spacing of 100 m in the simulation area, no water would overflow from the mine.
In this paper, a mathematical model was set up, taking the Fushun West Open-pit mine as the research area, using the GMS (groundwater modeling system) numerical simulation software, based on the analysis of the mining area and its surrounding area, geological and hydrogeological conditions, as well as the characteristics of the formation lithology and geological structure. Based on the geological exploration data of the working area and the analysis of water filling factors, a hydrogeological model was established to predict the water inflow, and the layout scheme of drainage well in equilibrium state was put forward. The results showed that according to the topographic characteristics of the mine, when five horizontal wells with depth of 100 m, length of 100 m and displacement volume of 10~20 m3/d were placed on the north and south sides of the mine, and four shafts with depth of 70~100 m and displacement volume of 20 m3/d were placed at the bottom of the mine according to the spacing of 100 m in the simulation area, no water would overflow from the mine.
2021, 39(1): 80-88.
doi: 10.13205/j.hjgc.202101012
Abstract:
Remote sensing image has wide spatial coverage and short update period, which is a feasible technology to extract water surface information in large area in time, and of great significance to the development, utilization, management and protection of water resources.In view of the influence of precipitation fluctuation within the year, this paper made full use of all available image data to construct the annual average water body index, so as to reduce the problem that was difficult to accurately reflect the water surface characteristics in a single period image. The Google Earth Engine (GEE) remote sensing cloud platform was used to solve the problem of low efficiency of traditional image download and desktop processing of massive image data. Taking Heilongjiang Basin as the research area, taking Landsat Image as data source, combined with topographic data, annual water surface and seasonal water surface from 1987 to 2019 were extracted. The results showed that:1) compared with the single period image data, the annual average water body index could reflect the time information of water surface more comprehensively, and the overall accuracy of water surface extraction was 95.32%, in which the annual and seasonal water surface were 96.59% and 94.61% respectively; 2) compared with the existing data products, the annual water surface extracted in this paper was more continuous, complete and of better quality; 3) in recent 32 years, the annual water surface area of Heilongjiang Basin fluctuated greatly, showing a decreasing trend, with an average annual decrease of 14.82 km2; the seasonal water surface was relatively stable, showing an increasing trend, with an average annual increase of 12.81 km2.
Remote sensing image has wide spatial coverage and short update period, which is a feasible technology to extract water surface information in large area in time, and of great significance to the development, utilization, management and protection of water resources.In view of the influence of precipitation fluctuation within the year, this paper made full use of all available image data to construct the annual average water body index, so as to reduce the problem that was difficult to accurately reflect the water surface characteristics in a single period image. The Google Earth Engine (GEE) remote sensing cloud platform was used to solve the problem of low efficiency of traditional image download and desktop processing of massive image data. Taking Heilongjiang Basin as the research area, taking Landsat Image as data source, combined with topographic data, annual water surface and seasonal water surface from 1987 to 2019 were extracted. The results showed that:1) compared with the single period image data, the annual average water body index could reflect the time information of water surface more comprehensively, and the overall accuracy of water surface extraction was 95.32%, in which the annual and seasonal water surface were 96.59% and 94.61% respectively; 2) compared with the existing data products, the annual water surface extracted in this paper was more continuous, complete and of better quality; 3) in recent 32 years, the annual water surface area of Heilongjiang Basin fluctuated greatly, showing a decreasing trend, with an average annual decrease of 14.82 km2; the seasonal water surface was relatively stable, showing an increasing trend, with an average annual increase of 12.81 km2.
2021, 39(1): 89-95,100.
doi: 10.13205/j.hjgc.202101013
Abstract:
Volatile organic compounds (VOCs) are a group of air pollutants with potentially adverse health effects, and also important precursors of both secondary organic aerosols and ozone. In this work, an online single photon ionization mass spectrometer (SPI-MS) was installed on a vehicle, and for the first time, we conducted a four-day mobile measurement of VOCs in the Nangjing Jiangbei Chemical Industry Park during March 2018. During the sampling period, the average concentration of total VOCs was 133.3 μg/m3, nighttime mean concentration (143.6 μg/m3) was higher than that during daytime (123.1 μg/m3), and mean mass concentration of workdays (226.7 μg/m3) was found to be much higher than that of weekend (39.9 μg/m3). We also obtained highly time-and spatially-resolved distributions of VOCs, and elucidated the characteristic species, and variations and dominant sources (factories) of the three key zones (Nangang Nanhua, Yangzi Shihua, and Huagong Dadao). Overall, alkanes and aromatics were the major contributors (both 31%) of the total VOCs, followed by alkenes (25%) and halocarbons (13%); while in terms of ozone formation potential, alkenes was the largest contributor (56%), followed by aromatics (32%), alkanes (9%) and halocarbons (3%). Our findings here could provide useful insights and guidances into the VOCs reduction measures and local ozone pollution control.
Volatile organic compounds (VOCs) are a group of air pollutants with potentially adverse health effects, and also important precursors of both secondary organic aerosols and ozone. In this work, an online single photon ionization mass spectrometer (SPI-MS) was installed on a vehicle, and for the first time, we conducted a four-day mobile measurement of VOCs in the Nangjing Jiangbei Chemical Industry Park during March 2018. During the sampling period, the average concentration of total VOCs was 133.3 μg/m3, nighttime mean concentration (143.6 μg/m3) was higher than that during daytime (123.1 μg/m3), and mean mass concentration of workdays (226.7 μg/m3) was found to be much higher than that of weekend (39.9 μg/m3). We also obtained highly time-and spatially-resolved distributions of VOCs, and elucidated the characteristic species, and variations and dominant sources (factories) of the three key zones (Nangang Nanhua, Yangzi Shihua, and Huagong Dadao). Overall, alkanes and aromatics were the major contributors (both 31%) of the total VOCs, followed by alkenes (25%) and halocarbons (13%); while in terms of ozone formation potential, alkenes was the largest contributor (56%), followed by aromatics (32%), alkanes (9%) and halocarbons (3%). Our findings here could provide useful insights and guidances into the VOCs reduction measures and local ozone pollution control.
2021, 39(1): 96-100.
doi: 10.13205/j.hjgc.202101014
Abstract:
A series of bimetallic and biassistant CuxMn1-xCe0.75Zr0.25Oy catalysts were prepared by sol-gel method. The catalytic degradation performance of toluene over the catalysts was tested in a fixed-bed reactor. The relationships between the catalytic activity of toluene degradation and catalyst structure were explored by XRD, H2-TPR, O2-TPD and Raman methods. It was found that the increase of copper content could enhance the interaction between Cu-Ce, and improve the oxygen vacancy concentration, lattice oxygen content and low temperature reducibility, thus promote the catalytic activity. Cu1CeZr catalyst exhibited the best activity for toluene degradation, and the temperature of complete degradation of toluene was 220℃, which was 60℃ lower than that of Mn1CeZr catalyst.
A series of bimetallic and biassistant CuxMn1-xCe0.75Zr0.25Oy catalysts were prepared by sol-gel method. The catalytic degradation performance of toluene over the catalysts was tested in a fixed-bed reactor. The relationships between the catalytic activity of toluene degradation and catalyst structure were explored by XRD, H2-TPR, O2-TPD and Raman methods. It was found that the increase of copper content could enhance the interaction between Cu-Ce, and improve the oxygen vacancy concentration, lattice oxygen content and low temperature reducibility, thus promote the catalytic activity. Cu1CeZr catalyst exhibited the best activity for toluene degradation, and the temperature of complete degradation of toluene was 220℃, which was 60℃ lower than that of Mn1CeZr catalyst.
2021, 39(1): 101-105,88.
doi: 10.13205/j.hjgc.202101015
Abstract:
The NO produced in the industrial production process causes serious pollution to the atmospheric environment. Selective catalytic oxidation absorption is the most valuable technology for denitration. The key to selective catalytic oxidation lies in the choice of catalyst. At present, the catalysts for catalytic oxidation of NO mainly include activated carbon catalysts, molecular sieve catalysts, noble metal catalysts and transition metal oxide catalysts. Among them, transition metal oxide catalysts have good catalytic activity, low price, simple preparation, etc., and are currently more promising catalysts. So for now, about the mechanism of the SCO all kinds of denitration catalyst, economic practical and oxidation at room temperature, good stability and resistance to toxicity to the catalyst preparation and catalytic oxidation of industrial waste gas process is the development direction of denitration catalyst in the future.
The NO produced in the industrial production process causes serious pollution to the atmospheric environment. Selective catalytic oxidation absorption is the most valuable technology for denitration. The key to selective catalytic oxidation lies in the choice of catalyst. At present, the catalysts for catalytic oxidation of NO mainly include activated carbon catalysts, molecular sieve catalysts, noble metal catalysts and transition metal oxide catalysts. Among them, transition metal oxide catalysts have good catalytic activity, low price, simple preparation, etc., and are currently more promising catalysts. So for now, about the mechanism of the SCO all kinds of denitration catalyst, economic practical and oxidation at room temperature, good stability and resistance to toxicity to the catalyst preparation and catalytic oxidation of industrial waste gas process is the development direction of denitration catalyst in the future.
2021, 39(1): 106-110,160.
doi: 10.13205/j.hjgc.202101016
Abstract:
In order to fully use of resources and reduce desulfurization cost, a large quantity of magnesium slag generated from the traditional technology was used to produce magnesium by Pidgeon process as the base. And we utilized the filtering generated powder dust in magnesium production gyration kiln dust wiper and magnesium production raw material dolomite as accessories and mixed at a certain ratio to manufacture the desulfurization agent for wet desulfurization,and researched the desulfurization effect of magnesium slag, powder dust, mineral in single, and mixed with each other and together as the desulfurization agent. The results proved that, the best desulfurization effect was achieved when magnesium slag:powder dust:mineral=10:0.3:0.035(mass ratio), then the combined desulfurization agent water solution (10.335 g/100 mL) could consume 67.58 mL dilute sulphuric acid with concentration of 1 mL/L. Alkalinity activate agent (Na2CO3, NaOH) was also added for further improving the desulfurization effect. The results showed that NaOH had better activate effect, then the combine desulfurization agen could consume 214.42 mL of dilute sulphuric acid when add 2% NaOH, which was 3.17 times of that before activation. SEM results showed that reaction area of composite desulfurization agent obviously increased after adding activate agent. The activated magnesium slag based composite desulfurization agent could be used for wet desulfurization of flue gas, which could realize the resource utilization and achieve the purpose of treating waste with waste, also have a good market prospect.
In order to fully use of resources and reduce desulfurization cost, a large quantity of magnesium slag generated from the traditional technology was used to produce magnesium by Pidgeon process as the base. And we utilized the filtering generated powder dust in magnesium production gyration kiln dust wiper and magnesium production raw material dolomite as accessories and mixed at a certain ratio to manufacture the desulfurization agent for wet desulfurization,and researched the desulfurization effect of magnesium slag, powder dust, mineral in single, and mixed with each other and together as the desulfurization agent. The results proved that, the best desulfurization effect was achieved when magnesium slag:powder dust:mineral=10:0.3:0.035(mass ratio), then the combined desulfurization agent water solution (10.335 g/100 mL) could consume 67.58 mL dilute sulphuric acid with concentration of 1 mL/L. Alkalinity activate agent (Na2CO3, NaOH) was also added for further improving the desulfurization effect. The results showed that NaOH had better activate effect, then the combine desulfurization agen could consume 214.42 mL of dilute sulphuric acid when add 2% NaOH, which was 3.17 times of that before activation. SEM results showed that reaction area of composite desulfurization agent obviously increased after adding activate agent. The activated magnesium slag based composite desulfurization agent could be used for wet desulfurization of flue gas, which could realize the resource utilization and achieve the purpose of treating waste with waste, also have a good market prospect.
2021, 39(1): 111-116,186.
doi: 10.13205/j.hjgc.202101017
Abstract:
This paper analyzed the development status, industrial layout and air pollution emission control of the coking industry in the Fenwei Plain, a key air pollution controlling area in China at present, analyzed the problems existing in air pollution control technologies in the process of coking production, and put forward the corresponding countermeasures based on the current local and national environmental requirements and the development status of pollution control technologies.
This paper analyzed the development status, industrial layout and air pollution emission control of the coking industry in the Fenwei Plain, a key air pollution controlling area in China at present, analyzed the problems existing in air pollution control technologies in the process of coking production, and put forward the corresponding countermeasures based on the current local and national environmental requirements and the development status of pollution control technologies.
2021, 39(1): 117-122.
doi: 10.13205/j.hjgc.202101018
Abstract:
Pyrolysis of rice husk in different atmospheres (by alternating the volume ratios of N2, O2, and CO2) were carried out on a small-scale fluidized bed to obtain the distribution pattern of the three-phase product of rice husk pyrolysis and the characteristics of the rice husk biochar. The functional groups and porous structure on the surface of biochar were analyzed by means of FTIR and BET, and the energy transfer during the pyrolysis of rice husk under different O2 concentrations were investigated. The results showed that increasing the concentration of O2 and CO2 were conducive to the transfer of pyrolysis products from the solid phase to the gas phase, which would reduce the biochar yield and the content of organic components in biochar, but it was conducive to the formation of porous structures and aromatic functional groups on the surface of biochar. Rice husk could achieve an energy consumption ratio of more than 80% and an energy recovery rate of more than 70%, under lower O2 concentration.
Pyrolysis of rice husk in different atmospheres (by alternating the volume ratios of N2, O2, and CO2) were carried out on a small-scale fluidized bed to obtain the distribution pattern of the three-phase product of rice husk pyrolysis and the characteristics of the rice husk biochar. The functional groups and porous structure on the surface of biochar were analyzed by means of FTIR and BET, and the energy transfer during the pyrolysis of rice husk under different O2 concentrations were investigated. The results showed that increasing the concentration of O2 and CO2 were conducive to the transfer of pyrolysis products from the solid phase to the gas phase, which would reduce the biochar yield and the content of organic components in biochar, but it was conducive to the formation of porous structures and aromatic functional groups on the surface of biochar. Rice husk could achieve an energy consumption ratio of more than 80% and an energy recovery rate of more than 70%, under lower O2 concentration.
2021, 39(1): 123-129.
doi: 10.13205/j.hjgc.202101019
Abstract:
In this study, the disposal possibility of anaerobic fermentation slurry produced in the process of anaerobic fermentation for heavy metal-containing rice straw was studied. The results showed that the circulation reflux of anaerobic fermentation slurry could accelerate the degradation of rice straw, including cellulose and hemicellulose. Meanwhile, the heavy metals released from rice straw in the anaerobic fermentation process was similar to that with original anaerobic fermentation slurry. The methane yields of 121.2, 282.6 mL/g VS was achieved under the solid to liquid ratio of 3.3%. Furthermore, the release percentages of Cu, Cd, Pb and Zn from rice straw arrived to 94.22%, 54.21%, 72.67% and 98.55%, respectively. The content of heavy metals in straw residues was significantly lower than the levels for the Urban Garbage Agricultural Control Standard in China (GB 8172-87) and could be backed to the field. After fermentation, the concentration of Cu, Cd, Pb and Zn in anaerobic fermentation slurry were 0.30, 0.073, 0.10, 2.57 mg/L respectively. The results showed that the anaerobic fermentation slurry recycled was available for the anaerobic fermentation of heavy metals-containing rice straw and beneficial to the release of heavy metals from rice straw.
In this study, the disposal possibility of anaerobic fermentation slurry produced in the process of anaerobic fermentation for heavy metal-containing rice straw was studied. The results showed that the circulation reflux of anaerobic fermentation slurry could accelerate the degradation of rice straw, including cellulose and hemicellulose. Meanwhile, the heavy metals released from rice straw in the anaerobic fermentation process was similar to that with original anaerobic fermentation slurry. The methane yields of 121.2, 282.6 mL/g VS was achieved under the solid to liquid ratio of 3.3%. Furthermore, the release percentages of Cu, Cd, Pb and Zn from rice straw arrived to 94.22%, 54.21%, 72.67% and 98.55%, respectively. The content of heavy metals in straw residues was significantly lower than the levels for the Urban Garbage Agricultural Control Standard in China (GB 8172-87) and could be backed to the field. After fermentation, the concentration of Cu, Cd, Pb and Zn in anaerobic fermentation slurry were 0.30, 0.073, 0.10, 2.57 mg/L respectively. The results showed that the anaerobic fermentation slurry recycled was available for the anaerobic fermentation of heavy metals-containing rice straw and beneficial to the release of heavy metals from rice straw.
2021, 39(1): 130-135.
doi: 10.13205/j.hjgc.202101020
Abstract:
An experiment was conducted to study the effect of pile turning on aerobic fermentation process and product properties and evaluate the best turning strategy of pig biogas residue. Seven treatments were conducted, which had different tuning time and frequency that were turned 1, 2 or 3 times at high-temperature of medium and late stages, as well as early, medium and late stages of cooling period. The results showed that composting could prolong the high temperature period of aerobic fermentation and accelerate the cooling rate in the cooling period. The results showed that turning 2 to 3 times in high temperature and cooling period could effectively promote the degradation of volatile solids, improve the humification degree of products and seed germination index. According to the harmless and maturity indexes of aerobic fermentation process, the best composting strategy was to turn the compost twice in the late high temperature period, the middle cooling period (T2), the middle high temperature period and the early cooling period (T3). In addition, the fermentation period could be shortened to 20 days after composting.
An experiment was conducted to study the effect of pile turning on aerobic fermentation process and product properties and evaluate the best turning strategy of pig biogas residue. Seven treatments were conducted, which had different tuning time and frequency that were turned 1, 2 or 3 times at high-temperature of medium and late stages, as well as early, medium and late stages of cooling period. The results showed that composting could prolong the high temperature period of aerobic fermentation and accelerate the cooling rate in the cooling period. The results showed that turning 2 to 3 times in high temperature and cooling period could effectively promote the degradation of volatile solids, improve the humification degree of products and seed germination index. According to the harmless and maturity indexes of aerobic fermentation process, the best composting strategy was to turn the compost twice in the late high temperature period, the middle cooling period (T2), the middle high temperature period and the early cooling period (T3). In addition, the fermentation period could be shortened to 20 days after composting.
2021, 39(1): 136-141,200.
doi: 10.13205/j.hjgc.202101021
Abstract:
The Gibbs free energy of reaction between various metal oxides and hydrochloric acid, was calculated to explore the feasibility of two-step hydrochloric acid leaching for scandium recovery from red mud produced in Bayer process. In order to achieve a high leaching rate of scandium ion and a high selectivity of scandium against other metals, orthogonal experiments of secondary acid leaching with low-concentration hydrochloric acid of about 2.5 mol/L were conducted. Design-Expert 8.0 software was utilized to analyze the experimental data, and the impacts of key factors, i.e. temperature, time duration, liquid-solid ratio, hydrochloric acid concentration on the leaching rate of various metal ions were discussed. The corresponding polynomial models were also established. Finally, the optimum operating conditions were determined as follows:leaching temperature of 70℃, duration of 70 min, liquid solid ratio of 6 and HCl concentration of 2.5 mol/L. A high leaching rate of more than 80% was achieved for scandium under such condition, while the leaching rates for the key impurities, i.e. Fe, Zr and Ti kept low.
The Gibbs free energy of reaction between various metal oxides and hydrochloric acid, was calculated to explore the feasibility of two-step hydrochloric acid leaching for scandium recovery from red mud produced in Bayer process. In order to achieve a high leaching rate of scandium ion and a high selectivity of scandium against other metals, orthogonal experiments of secondary acid leaching with low-concentration hydrochloric acid of about 2.5 mol/L were conducted. Design-Expert 8.0 software was utilized to analyze the experimental data, and the impacts of key factors, i.e. temperature, time duration, liquid-solid ratio, hydrochloric acid concentration on the leaching rate of various metal ions were discussed. The corresponding polynomial models were also established. Finally, the optimum operating conditions were determined as follows:leaching temperature of 70℃, duration of 70 min, liquid solid ratio of 6 and HCl concentration of 2.5 mol/L. A high leaching rate of more than 80% was achieved for scandium under such condition, while the leaching rates for the key impurities, i.e. Fe, Zr and Ti kept low.
2021, 39(1): 142-147.
doi: 10.13205/j.hjgc.202101022
Abstract:
Using Chinese herbal residue as a conditioner and an external carbon source, the effect of different quality ratios on the composting process of food waste and municipal sludge were investigated by EEM spectra. In addition, the microbial communities in different piles were analyzed by using high throughput sequencing technology. The results of the EEM spectra showed that the addition of Chinese herbal residue accelerated the maturity process of composting. With the increase of the dosage, the effect was continuously enhanced. According to high throughput sequencing analysis, with the increase of the dosage of Chinese herbal residue, the microbial biodiversity in the piles gradually decreased, but the microbial community richness increased. The relative abundance of Proteobacteria decreased by adding Chinese herbal residue, while the relative abundance of Firmicutes increased. Meanwhile, adding a weight ratio 5% of Chinese herbal residue could improve the number of Clostridia, so as to promote the decomposition of cellulose in the piles, and avoid the local hardening of the piles caused by the excessive addition of Chinese herbal residue. In general, the addition of 5% Chinese herbal residue had best promoting effect on the composting process of food waste and municipal sludge.
Using Chinese herbal residue as a conditioner and an external carbon source, the effect of different quality ratios on the composting process of food waste and municipal sludge were investigated by EEM spectra. In addition, the microbial communities in different piles were analyzed by using high throughput sequencing technology. The results of the EEM spectra showed that the addition of Chinese herbal residue accelerated the maturity process of composting. With the increase of the dosage, the effect was continuously enhanced. According to high throughput sequencing analysis, with the increase of the dosage of Chinese herbal residue, the microbial biodiversity in the piles gradually decreased, but the microbial community richness increased. The relative abundance of Proteobacteria decreased by adding Chinese herbal residue, while the relative abundance of Firmicutes increased. Meanwhile, adding a weight ratio 5% of Chinese herbal residue could improve the number of Clostridia, so as to promote the decomposition of cellulose in the piles, and avoid the local hardening of the piles caused by the excessive addition of Chinese herbal residue. In general, the addition of 5% Chinese herbal residue had best promoting effect on the composting process of food waste and municipal sludge.
2021, 39(1): 148-153.
doi: 10.13205/j.hjgc.202101023
Abstract:
The high ionic strength of bauxite liquor could suppress swelling of montmorillonite, which results in sodium bentonite clay liner (GCL) that was too permeable to be used as an impermeable liner in red mud treatment facilities. The mechanism controlling of strongly alkaline bauxite liquor and sodium bentonite clay liner was investigated through the infiltration process of sodium bentonite clay liner and two types of bauxite liquor. The results showed that hydraulic conductivity of natural sodium bentonite (Na-GCL) and artificial sodium bentonite (Ar-GCL) was closely related to ionic strength of bauxite liquor. As ionic strength increased, hydraulic conductivity systematically increased. Hydraulic conductivity of Shandong bauxite liquor with high ionic strength was the largest, 7.8×10-7 and 3.2×10-7 m/s, respectively. Hydraulic conductivity was positively related to swelling index. Through the analysis of the microstructure diagram of SEM scanning, swelling mechanism of bentonite controlled its hydraulic conductivity. High ionic strength caused permeable expansion of bentonite mineral layer, and absorbed a large amount of water, which reduced the porosity and changed the flow path of the fluid, resulting in an increase of hydraulic conductivity.
The high ionic strength of bauxite liquor could suppress swelling of montmorillonite, which results in sodium bentonite clay liner (GCL) that was too permeable to be used as an impermeable liner in red mud treatment facilities. The mechanism controlling of strongly alkaline bauxite liquor and sodium bentonite clay liner was investigated through the infiltration process of sodium bentonite clay liner and two types of bauxite liquor. The results showed that hydraulic conductivity of natural sodium bentonite (Na-GCL) and artificial sodium bentonite (Ar-GCL) was closely related to ionic strength of bauxite liquor. As ionic strength increased, hydraulic conductivity systematically increased. Hydraulic conductivity of Shandong bauxite liquor with high ionic strength was the largest, 7.8×10-7 and 3.2×10-7 m/s, respectively. Hydraulic conductivity was positively related to swelling index. Through the analysis of the microstructure diagram of SEM scanning, swelling mechanism of bentonite controlled its hydraulic conductivity. High ionic strength caused permeable expansion of bentonite mineral layer, and absorbed a large amount of water, which reduced the porosity and changed the flow path of the fluid, resulting in an increase of hydraulic conductivity.
2021, 39(1): 154-160.
doi: 10.13205/j.hjgc.202101024
Abstract:
Utilizing the AMPTS fully automated test system of methane production potential, first-order hydrolysis model, modified Gompertz model and logistic model, based on understanding the physical and chemical properties of biochar, through modeling and comparative analysis the hydrolysis rate, the methanogenic potential and the maximum methane yield of anaerobic fermentation to research the effect of woody biochar on sequential batch wet anaerobic fermentation. The results showed that sawdust biochar had significant effect on substrate hydrolysis, the methane yield and cumulative methane production in the pre-stage anaerobic fermentation. The effect of sawdust biochar on the hydrolysis rate was stronger than that of fruit wood biochar and activated carbon in the early stage of anaerobic fermentation, which was weaker than that of coconut shell charcoal. The buffering capacity of sawdust biochar on anaerobic fermentation system was stronger than that of coconut shell biochar and activated carbon. The Enhanced effect of sawdust biochar on anaerobic fermentation was negatively correlated with the particle size of biochar. The smaller the particle size of the sawdust biochar, the more significant the effect of anaerobic fermentation was. When the particle size was less than 0.5 millimeter, the strengthening effect was best, the hydrolysis rate was increased by 33.93%, the maximum methanogenesis rate was increased by 19.32%, and the lag period was shortened by 51.28%.
Utilizing the AMPTS fully automated test system of methane production potential, first-order hydrolysis model, modified Gompertz model and logistic model, based on understanding the physical and chemical properties of biochar, through modeling and comparative analysis the hydrolysis rate, the methanogenic potential and the maximum methane yield of anaerobic fermentation to research the effect of woody biochar on sequential batch wet anaerobic fermentation. The results showed that sawdust biochar had significant effect on substrate hydrolysis, the methane yield and cumulative methane production in the pre-stage anaerobic fermentation. The effect of sawdust biochar on the hydrolysis rate was stronger than that of fruit wood biochar and activated carbon in the early stage of anaerobic fermentation, which was weaker than that of coconut shell charcoal. The buffering capacity of sawdust biochar on anaerobic fermentation system was stronger than that of coconut shell biochar and activated carbon. The Enhanced effect of sawdust biochar on anaerobic fermentation was negatively correlated with the particle size of biochar. The smaller the particle size of the sawdust biochar, the more significant the effect of anaerobic fermentation was. When the particle size was less than 0.5 millimeter, the strengthening effect was best, the hydrolysis rate was increased by 33.93%, the maximum methanogenesis rate was increased by 19.32%, and the lag period was shortened by 51.28%.
2021, 39(1): 161-165.
doi: 10.13205/j.hjgc.202101025
Abstract:
In China, steel slag is produced with a output higher than 100 million ton per year. Whereas, the resource utilization rate of steel slag is at a low level of about 30%, which is far lower than the developer countries, especially in the road construction and internal recycling field. Facing the problem of stability and resource utilization, steel slag treatment and utilization technologies at home and abroad were discussed in this paper. The new technology-self-slaking high pressure technology, is a leading process and almost overcome nearly all the defects presented in the traditional processes, such as low feasibility, low stability, and high pollution. Furthermore, we should develop more new comprehensive utilization technology with high added value and low emission, in order to solve the problem of low expansion of steel slag, and promote the utilization of steel slag in structural concrete.
In China, steel slag is produced with a output higher than 100 million ton per year. Whereas, the resource utilization rate of steel slag is at a low level of about 30%, which is far lower than the developer countries, especially in the road construction and internal recycling field. Facing the problem of stability and resource utilization, steel slag treatment and utilization technologies at home and abroad were discussed in this paper. The new technology-self-slaking high pressure technology, is a leading process and almost overcome nearly all the defects presented in the traditional processes, such as low feasibility, low stability, and high pollution. Furthermore, we should develop more new comprehensive utilization technology with high added value and low emission, in order to solve the problem of low expansion of steel slag, and promote the utilization of steel slag in structural concrete.
2021, 39(1): 166-173.
doi: 10.13205/j.hjgc.202101026
Abstract:
In this study, a total of 48 sample sites were selected from eight soils with different land use types (including dry land, park, woodland, beach, irrigated land, green belt, residential area and wasteland) in suburban areas of Tianjin, to study the content, composition, distribution characteristics and influencing factors of antibiotics in the soil in Tianjin. Ultra-high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was used to detect the residual levels of 12 antibiotics in five categories. Meanwhile, the key factors affecting the pollution characteristics of antibiotics were analyzed by the physical and chemical properties of the soil and microbial community structure. The results showed that the concentration of antibiotics was detected in the range of (4.35~1.35)×103 μg/kg, in the general sequence of tetracyclines (TCs)>sulfonamides (SAs)>quinolones (QNs)>macrolides (MLs)>β-lactams, in which antibiotic content in dry land soil was significantly higher than the other soil, mainly related to organic fertilizer application. Principal component analysis (PCA) showed that the composition of antibiotics in the soil of the dry land and park was significantly different from the others, which was related to fertilization of livestock and poultry manure and the release of antibiotics in exogenous life. Redundant analysis (RDA) of environmental factors and antibiotics showed that soil environmental factors (total nitrogen (TN), total phosphorus (TP), copper (Cu), zinc (Zn), pH) had a strong influence on the composition of antibiotics (P<0.05). Spearman correlation between microorganisms and antibiotics showed that Planctomyce, Sphingomonas, Gemmatimona, Roseiflexus, Steroidobacter, Acidobacteria_bacterium_WX27, Lysobacter, Thiobacillus had significant correlations with antibiotics (P<0.05). Among them, microorganisms were strongly related to tetracycline and quinolone antibiotics. This study could provide a scientific basis for the prevention and control of soil antibiotic pollution.
In this study, a total of 48 sample sites were selected from eight soils with different land use types (including dry land, park, woodland, beach, irrigated land, green belt, residential area and wasteland) in suburban areas of Tianjin, to study the content, composition, distribution characteristics and influencing factors of antibiotics in the soil in Tianjin. Ultra-high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was used to detect the residual levels of 12 antibiotics in five categories. Meanwhile, the key factors affecting the pollution characteristics of antibiotics were analyzed by the physical and chemical properties of the soil and microbial community structure. The results showed that the concentration of antibiotics was detected in the range of (4.35~1.35)×103 μg/kg, in the general sequence of tetracyclines (TCs)>sulfonamides (SAs)>quinolones (QNs)>macrolides (MLs)>β-lactams, in which antibiotic content in dry land soil was significantly higher than the other soil, mainly related to organic fertilizer application. Principal component analysis (PCA) showed that the composition of antibiotics in the soil of the dry land and park was significantly different from the others, which was related to fertilization of livestock and poultry manure and the release of antibiotics in exogenous life. Redundant analysis (RDA) of environmental factors and antibiotics showed that soil environmental factors (total nitrogen (TN), total phosphorus (TP), copper (Cu), zinc (Zn), pH) had a strong influence on the composition of antibiotics (P<0.05). Spearman correlation between microorganisms and antibiotics showed that Planctomyce, Sphingomonas, Gemmatimona, Roseiflexus, Steroidobacter, Acidobacteria_bacterium_WX27, Lysobacter, Thiobacillus had significant correlations with antibiotics (P<0.05). Among them, microorganisms were strongly related to tetracycline and quinolone antibiotics. This study could provide a scientific basis for the prevention and control of soil antibiotic pollution.
2021, 39(1): 174-180.
doi: 10.13205/j.hjgc.202101027
Abstract:
Taking 36 sampling points arranged along the Niugu River and Xihe River inlets as the research objects, SMT method, elemental analyzer and potassium dichromate method were employed to monitor the contents of TP, TN and OM, respectively. Spatial patterns and correlations of TN, TP and OM were examined. At the same time, comprehensive pollution index and organic pollution index was employed to evaluate pollution status. The results showed that the average contents of TN, TP and OM were 697.18 mg/kg, 920.31 mg/kg and 4.47%, respectively. The content of TN and OM in the middle reaches was higher than that in the upper and lower reaches(A,B>C,D), and the content of TP in the middle and lower reaches was higher than that in the upper reaches(A,B,D>C); C/N of each part indicated that the organic matter of C, A and D segments mainly came from external sources, and the internal and external sources of B segments were basically balanced. The average values of comprehensive pollution index and organic pollution index of surface sediment in Niugu River were 1.38 and 0.19, respectively. Both evaluation results showed that the surface sediment of Niugu River was slightly polluted, but the average pollution index of TP was 1.36, which was in severe pollution condition. The Pearson correlation analysis between indicators showed that TN, TP, and OM had significantly positively correlation with each other (P<0.01).
Taking 36 sampling points arranged along the Niugu River and Xihe River inlets as the research objects, SMT method, elemental analyzer and potassium dichromate method were employed to monitor the contents of TP, TN and OM, respectively. Spatial patterns and correlations of TN, TP and OM were examined. At the same time, comprehensive pollution index and organic pollution index was employed to evaluate pollution status. The results showed that the average contents of TN, TP and OM were 697.18 mg/kg, 920.31 mg/kg and 4.47%, respectively. The content of TN and OM in the middle reaches was higher than that in the upper and lower reaches(A,B>C,D), and the content of TP in the middle and lower reaches was higher than that in the upper reaches(A,B,D>C); C/N of each part indicated that the organic matter of C, A and D segments mainly came from external sources, and the internal and external sources of B segments were basically balanced. The average values of comprehensive pollution index and organic pollution index of surface sediment in Niugu River were 1.38 and 0.19, respectively. Both evaluation results showed that the surface sediment of Niugu River was slightly polluted, but the average pollution index of TP was 1.36, which was in severe pollution condition. The Pearson correlation analysis between indicators showed that TN, TP, and OM had significantly positively correlation with each other (P<0.01).
2021, 39(1): 181-186.
doi: 10.13205/j.hjgc.202101028
Abstract:
In order to understand the theory of electrokinetic remediation (EKR) and provide scientific basis for the remediation of the contaminated sites, the vertical electrokinetic remediation technology was used to the real and artificial contaminated soil and compared the current intensity, pH and heavy metal translocation between the two types of soil. The main experimental results could be listed as follows:1) During the process of EKR, the real and artificial contaminated soil had similar current peak shape, but the current value of artificial soil was about twice of that of the real soil, indicating that the artificial soil contained more mobile ions than the real soil. 2) After the EKR, the real and artificial contaminated soil had similar pH changing trend:the soil pH near the anode was lowered, but the soil pH near the cathode was increased. The increase of the cathode pH could fix the heavy metals in deep layers of soil. 3) For the real soil, the vertical EKR removed Cd, Pb, Cu and Zn from 0~5 cm to deeper layers, and similarly from 5~10 cm soil layer for Cd and Zn, but Pb and Cu accumulated in the 5~10 cm soil layer, and the other soil layer did not change significantly. 4) For the artificial soil, Cd migrated obviously and accumulated at the deepest layer (35~40 cm). Zn and Cu were removed from the 0~20 cm layer, but Pb was only removed from the 0~5 cm layer. The other soil layers did not significantly change. 5) The real soil had a significantly lower heavy metals translocation rates than the artificial soil, probably due to the heavy metals in artificial soil had shorter aging time (for 2 months), and Cd and Zn had a high mobility. Therefore, the experimental results obtained from artificial soil might not be able to be applied to the actually contaminated soil.
In order to understand the theory of electrokinetic remediation (EKR) and provide scientific basis for the remediation of the contaminated sites, the vertical electrokinetic remediation technology was used to the real and artificial contaminated soil and compared the current intensity, pH and heavy metal translocation between the two types of soil. The main experimental results could be listed as follows:1) During the process of EKR, the real and artificial contaminated soil had similar current peak shape, but the current value of artificial soil was about twice of that of the real soil, indicating that the artificial soil contained more mobile ions than the real soil. 2) After the EKR, the real and artificial contaminated soil had similar pH changing trend:the soil pH near the anode was lowered, but the soil pH near the cathode was increased. The increase of the cathode pH could fix the heavy metals in deep layers of soil. 3) For the real soil, the vertical EKR removed Cd, Pb, Cu and Zn from 0~5 cm to deeper layers, and similarly from 5~10 cm soil layer for Cd and Zn, but Pb and Cu accumulated in the 5~10 cm soil layer, and the other soil layer did not change significantly. 4) For the artificial soil, Cd migrated obviously and accumulated at the deepest layer (35~40 cm). Zn and Cu were removed from the 0~20 cm layer, but Pb was only removed from the 0~5 cm layer. The other soil layers did not significantly change. 5) The real soil had a significantly lower heavy metals translocation rates than the artificial soil, probably due to the heavy metals in artificial soil had shorter aging time (for 2 months), and Cd and Zn had a high mobility. Therefore, the experimental results obtained from artificial soil might not be able to be applied to the actually contaminated soil.
2021, 39(1): 187-193.
doi: 10.13205/j.hjgc.202101029
Abstract:
Microplastics had serious impact on soil ecosystem with the increasing concern. However, few studies on the migration of microplastics in the food chain of soil animals and their toxicological effects were available. In order to explore the biological transfer effect of sub-microplastics, four different materials, components of waste, heat preservation cotton, wheat bran-thermal insulation cotton and fine insulation cotton treated by Folsomia Candida, were used as a treatment factor to study the physiological and ecological effects of sub-microplastics on soil collembolans. The results showed that:1) on the 7th day, all the collembolans began to molt, and the larval mortality rates of the groups fed with heat preservation cotton, wheat bran heat preservation cotton and fine heat preservation cotton were 1.67%, 1.67% and 5%, respectively; 2) on the 14th day, the amount of molting increased, and the mortality of larvae in the groups of heat preservation cotton and fine heat preservation cotton was 6.67% and 5%, respectively, the oviposition of adults in each group increased sharply, and the oviposition rate of the control group fed with yeast was significantly higher than that of the treatment group; 3) on the 28th day, the increase of molting amount slowed down, except for the waste group, the larvae of each group increased; 4) compared with the control group, the molting, oviposition and biomass of the control group were the highest, and the body length increased significantly (P<0.05). The results of this study would further improve the basic data of the toxicological effects of sub-microplastics on soil animals, and provide theoretical basis for ecological risk assessment of sub-microplastics in soil environment.
Microplastics had serious impact on soil ecosystem with the increasing concern. However, few studies on the migration of microplastics in the food chain of soil animals and their toxicological effects were available. In order to explore the biological transfer effect of sub-microplastics, four different materials, components of waste, heat preservation cotton, wheat bran-thermal insulation cotton and fine insulation cotton treated by Folsomia Candida, were used as a treatment factor to study the physiological and ecological effects of sub-microplastics on soil collembolans. The results showed that:1) on the 7th day, all the collembolans began to molt, and the larval mortality rates of the groups fed with heat preservation cotton, wheat bran heat preservation cotton and fine heat preservation cotton were 1.67%, 1.67% and 5%, respectively; 2) on the 14th day, the amount of molting increased, and the mortality of larvae in the groups of heat preservation cotton and fine heat preservation cotton was 6.67% and 5%, respectively, the oviposition of adults in each group increased sharply, and the oviposition rate of the control group fed with yeast was significantly higher than that of the treatment group; 3) on the 28th day, the increase of molting amount slowed down, except for the waste group, the larvae of each group increased; 4) compared with the control group, the molting, oviposition and biomass of the control group were the highest, and the body length increased significantly (P<0.05). The results of this study would further improve the basic data of the toxicological effects of sub-microplastics on soil animals, and provide theoretical basis for ecological risk assessment of sub-microplastics in soil environment.
2021, 39(1): 194-200.
doi: 10.13205/j.hjgc.202101030
Abstract:
The effect of AM fungus inoculation on physiological, biochemical and photosynthetic characteristics of caragana leaves under soil compaction stress was studied. The results showed that the soil compaction led to the antioxidant enzymes activity of SOD, POD, CAT decreased, the content of proline, soluble sugar and soluble protein decreased, and the relative electrical conductivity and malondialdehyde increased significantly. Inoculation of AM fungus could improve the physiological characteristics of caragana leaves and enhance photosynthesis. Under soil compaction stress, the activity of antioxidant enzyme SOD, POD and CAT in caragana increased by 1.34, 1.65, 1.51 after AMF inoculation. The content of soluble sugar and soluble protein increased by 33.90% and 5.30% respectively, and the content of proline decreased by 53.20%. The relative conductivity and malondialdehyde content of the leaves decreased significantly by 15.58% and 19.98%. The secretion of hormone regulating substances IAA, CTK and GA increased by 18.39%, 45.19% and 14.40%, and ABA decreased by 34.33% with the inoculation of AMF. The net photosynthetic rate, stomatal conductance and transpiration rate of leaves were significantly increased. The results showed that the inoculation of AMF could improve antioxidant enzyme activity, regulate osmotic substance and hormone secretion, reduce lipid peroxidation level of cell membrane, maintain cell structure stability, promote photosynthesis and increase productivity. In the mining area with serious soil compaction, the inoculation of AMF could improve the ability of caragana to resist compaction stress, and improve the quality of vegetation restoration in mining areas.
The effect of AM fungus inoculation on physiological, biochemical and photosynthetic characteristics of caragana leaves under soil compaction stress was studied. The results showed that the soil compaction led to the antioxidant enzymes activity of SOD, POD, CAT decreased, the content of proline, soluble sugar and soluble protein decreased, and the relative electrical conductivity and malondialdehyde increased significantly. Inoculation of AM fungus could improve the physiological characteristics of caragana leaves and enhance photosynthesis. Under soil compaction stress, the activity of antioxidant enzyme SOD, POD and CAT in caragana increased by 1.34, 1.65, 1.51 after AMF inoculation. The content of soluble sugar and soluble protein increased by 33.90% and 5.30% respectively, and the content of proline decreased by 53.20%. The relative conductivity and malondialdehyde content of the leaves decreased significantly by 15.58% and 19.98%. The secretion of hormone regulating substances IAA, CTK and GA increased by 18.39%, 45.19% and 14.40%, and ABA decreased by 34.33% with the inoculation of AMF. The net photosynthetic rate, stomatal conductance and transpiration rate of leaves were significantly increased. The results showed that the inoculation of AMF could improve antioxidant enzyme activity, regulate osmotic substance and hormone secretion, reduce lipid peroxidation level of cell membrane, maintain cell structure stability, promote photosynthesis and increase productivity. In the mining area with serious soil compaction, the inoculation of AMF could improve the ability of caragana to resist compaction stress, and improve the quality of vegetation restoration in mining areas.
