期刊,Environmental technology 2025年46卷13/16期_国家学术搜索

Wind tunnel experimental study on the influence of super-large natural ventilation cooling tower on the flow and diffusion of pollutants

Ruojie LiJunfang ZhangYichen YaoMinghua Lyu...

2281-2291页

查看更多>>摘要：In this paper, a wind tunnel experiment was carried out to study the atmospheric flow and pollutant diffusion around a super-large natural ventilation cooling tower of a nuclear power plant. Considering the effect of the natural ventilation of the cooling tower, with the chimney as the center, X-type hot-wire probes were used to measure the average flow field and turbulence structure of the atmosphere around the cooling tower and other complexes, and pollutant diffusion studies were carried out by tracer experiments. The results show that the super-large natural ventilation cooling tower and its thermal plume emission have a significant effect on pollutant flow and diffusion, changing the trajectory of the plume. When the chimney is located upwind of the cooling tower, some pollutants are emitted secondly due to the entrainment effect through the cooling tower when the plume passes through the natural ventilation cooling tower, regardless of whether or not the cooling tower is operating. Compared with the cooling tower that does not operate, the thermal plume and natural ventilation effects generated by the cooling tower during operation cause the plume dispersion range to widen, the maximum concentration to decrease, and the impact on vertical diffusion to be more significant than that on horizontal diffusion.

原文链接:

NETL
NSTL
Taylor & Francis

Wind tunnel experimental study on the influence of super-large natural ventilation cooling tower on the flow and diffusion of pollutants

Ruojie LiJunfang ZhangYichen YaoMinghua Lyu...

2281-2291页

查看更多>>摘要：In this paper, a wind tunnel experiment was carried out to study the atmospheric flow and pollutant diffusion around a super-large natural ventilation cooling tower of a nuclear power plant. Considering the effect of the natural ventilation of the cooling tower, with the chimney as the center, X-type hot-wire probes were used to measure the average flow field and turbulence structure of the atmosphere around the cooling tower and other complexes, and pollutant diffusion studies were carried out by tracer experiments. The results show that the super-large natural ventilation cooling tower and its thermal plume emission have a significant effect on pollutant flow and diffusion, changing the trajectory of the plume. When the chimney is located upwind of the cooling tower, some pollutants are emitted secondly due to the entrainment effect through the cooling tower when the plume passes through the natural ventilation cooling tower, regardless of whether or not the cooling tower is operating. Compared with the cooling tower that does not operate, the thermal plume and natural ventilation effects generated by the cooling tower during operation cause the plume dispersion range to widen, the maximum concentration to decrease, and the impact on vertical diffusion to be more significant than that on horizontal diffusion.

原文链接:

NETL
NSTL
Taylor & Francis

Response surface optimisation for corona discharge treatment of nicosulfuron in water

Xinjun ShenYuncui YangSiyu ZhangFan He...

2292-2305页

查看更多>>摘要：Sulfonylurea herbicides are the most widely used herbicides in the world, which are widely used in the prevention and control of weeds in rice, wheat, soybean and other fields. Long-term application will cause environmental pollution, and the use of plasma technology to degrade herbicides in water is expected to be an effective method to restore pollution. In this experiment, corona discharge plasma was used to treat nicosulfuron in water, and the response surface method was used to optimise the operating conditions of the single system of corona discharge treatment of nicosulfuron and the synergistic system of corona discharge treatment of nicosulfuron with the addition of persulfate. The results showed that the degradation rate of nicosulfuron was 75.08% after 10 min under the optimum operating condition of single system. Under the optimum operating conditions, the degradation rate of nicosulfuron after 10 min was 100%. The R2 and P values of the two system models were both greater than 9.3 and less than 0.01, and the reliability of the simulated degradation rate data was verified by experiments, which provided basic data for the future research on the use of low temperature plasma to degrade herbicides.

原文链接:

NETL
NSTL
Taylor & Francis

Response surface optimisation for corona discharge treatment of nicosulfuron in water

Xinjun ShenYuncui YangSiyu ZhangFan He...

2292-2305页

查看更多>>摘要：Sulfonylurea herbicides are the most widely used herbicides in the world, which are widely used in the prevention and control of weeds in rice, wheat, soybean and other fields. Long-term application will cause environmental pollution, and the use of plasma technology to degrade herbicides in water is expected to be an effective method to restore pollution. In this experiment, corona discharge plasma was used to treat nicosulfuron in water, and the response surface method was used to optimise the operating conditions of the single system of corona discharge treatment of nicosulfuron and the synergistic system of corona discharge treatment of nicosulfuron with the addition of persulfate. The results showed that the degradation rate of nicosulfuron was 75.08% after 10 min under the optimum operating condition of single system. Under the optimum operating conditions, the degradation rate of nicosulfuron after 10 min was 100%. The R2 and P values of the two system models were both greater than 9.3 and less than 0.01, and the reliability of the simulated degradation rate data was verified by experiments, which provided basic data for the future research on the use of low temperature plasma to degrade herbicides.

原文链接:

NETL
NSTL
Taylor & Francis

Impact of anode surface modifications on microbial fuel cell performance and algal biomass production

Necla AltmBasar Uyar

2306-2317页

查看更多>>摘要：in this study, the performance of dual-chamber microbial fuel cells with carbon fiber (CF) anodes surface modified by multi-walled carbon nanotube coating (CF-MWCNT) and nitric acid treatment (CF-HNO_3) was compared. The performance of all these modified anodes was found to be better than bare electrode. The modified anodes were shown to significantly outperform the bare electrode anodes. CF-MWCNT and CF-HNO_3 modification increased the maximum power density by 1.60 and 2.88 times to 107 and 193 mw/m~2, respectively, compared to the bare electrode anode (67 mW/m~2). Due to the effect of the modifications, biofilm formation became more denser and stable, the biodegradation rate of organic matter increased and more efficient electron transfer was achieved on the anode surface. These results present effective and simple methods to enhance power generation with carbon fiber electrodes and also suggest ideas that can further improve the performance of modified carbon fiber electrodes. The content of algal biomass obtained in the cathode chamber was analyzed and the highest biomass with 0.71 g/L was obtained in the cell with CF-HNO_3 anode. Carbohydrate, protein and lipid contents were found to be 55%, 15.4% and 24%, respectively. In conclusion, this study demonstrates that surface modifications of carbon fiber anodes are an effective method to enhance the power generation performance of microbial fuel cells and reveals that this approach offers a viable strategy to improve energy efficiency.

原文链接:

NETL
NSTL
Taylor & Francis

Impact of anode surface modifications on microbial fuel cell performance and algal biomass production

Necla AltmBasar Uyar

2306-2317页

查看更多>>摘要：in this study, the performance of dual-chamber microbial fuel cells with carbon fiber (CF) anodes surface modified by multi-walled carbon nanotube coating (CF-MWCNT) and nitric acid treatment (CF-HNO_3) was compared. The performance of all these modified anodes was found to be better than bare electrode. The modified anodes were shown to significantly outperform the bare electrode anodes. CF-MWCNT and CF-HNO_3 modification increased the maximum power density by 1.60 and 2.88 times to 107 and 193 mw/m~2, respectively, compared to the bare electrode anode (67 mW/m~2). Due to the effect of the modifications, biofilm formation became more denser and stable, the biodegradation rate of organic matter increased and more efficient electron transfer was achieved on the anode surface. These results present effective and simple methods to enhance power generation with carbon fiber electrodes and also suggest ideas that can further improve the performance of modified carbon fiber electrodes. The content of algal biomass obtained in the cathode chamber was analyzed and the highest biomass with 0.71 g/L was obtained in the cell with CF-HNO_3 anode. Carbohydrate, protein and lipid contents were found to be 55%, 15.4% and 24%, respectively. In conclusion, this study demonstrates that surface modifications of carbon fiber anodes are an effective method to enhance the power generation performance of microbial fuel cells and reveals that this approach offers a viable strategy to improve energy efficiency.

原文链接:

NETL
NSTL
Taylor & Francis

Multi-stage anoxic/oxic sequencing batch reactor realizes shortcut nitrogen removal for anaerobically co-digested liquor of municipal sludge and urban organic wastes

Rui GengYong ChengHaixin JiangShiting Liu...

2318-2330页

查看更多>>摘要：Nitrogen removal from the combined anaerobic digestion dehydration liquor (CADDL) of municipal sludge and urban organic wastes is challenging due to high ammonium concentrations, low C/N ratio, and poor biodegradability. This study proposes a multi-stage anoxic/oxic (A/0) sequencing batch reactor with step feeding to realize partial nitrification and denitrification for shortcut nitrogen removal from the CADDL. We investigated the effects of external carbon source (acetate), dissolved oxygen (DO), A/0 duration ratio, and A/0 stage number on biological nitrogen removal. Moreover, we assessed the microbial community structure and nitrogen removal pathway. The results showed that the C/N consumption ratio for nitrite reduction to dinitrogen was 3.0 mg COD/mg N, and denitrifying bacteria yielded about 0.43. The optimal dosage of acetate was 2.2 mg COD/mg N. High DO concentration (1.5～3.0 mg/L) in the aerobic stage improved the ammonia-oxidizing bacteria activity and nitrogen removal rather than worsening the nitritation. A high A/O duration ratio (50 min/60 min) was conducive to complete denitrification of nitrite. The three-stage A/O had an excellent nitrogen removal performance. Under optimal conditions, the nitrite accumulation ratio of nitritation and the total inorganic nitrogen removal reached 100% and 90.1%, respectively. The dominant ammonia-oxidizing bacteria was the genus Nitrosomonas (0.76% abundance), and the dominant denitrifying bacteria was Thauera (0.24% abundance). The nitrite-oxidizing bacteria were not detected, confirming that the biological nitrogen removal pathway was partial nitrification and denitrification. These findings provide a feasible option for the low-carbon nitrogen removal treatment for the CADDL of municipal sludge and urban organic wastes.

原文链接:

NETL
NSTL
Taylor & Francis

Multi-stage anoxic/oxic sequencing batch reactor realizes shortcut nitrogen removal for anaerobically co-digested liquor of municipal sludge and urban organic wastes

Rui GengYong ChengHaixin JiangShiting Liu...

2318-2330页

查看更多>>摘要：Nitrogen removal from the combined anaerobic digestion dehydration liquor (CADDL) of municipal sludge and urban organic wastes is challenging due to high ammonium concentrations, low C/N ratio, and poor biodegradability. This study proposes a multi-stage anoxic/oxic (A/0) sequencing batch reactor with step feeding to realize partial nitrification and denitrification for shortcut nitrogen removal from the CADDL. We investigated the effects of external carbon source (acetate), dissolved oxygen (DO), A/0 duration ratio, and A/0 stage number on biological nitrogen removal. Moreover, we assessed the microbial community structure and nitrogen removal pathway. The results showed that the C/N consumption ratio for nitrite reduction to dinitrogen was 3.0 mg COD/mg N, and denitrifying bacteria yielded about 0.43. The optimal dosage of acetate was 2.2 mg COD/mg N. High DO concentration (1.5～3.0 mg/L) in the aerobic stage improved the ammonia-oxidizing bacteria activity and nitrogen removal rather than worsening the nitritation. A high A/O duration ratio (50 min/60 min) was conducive to complete denitrification of nitrite. The three-stage A/O had an excellent nitrogen removal performance. Under optimal conditions, the nitrite accumulation ratio of nitritation and the total inorganic nitrogen removal reached 100% and 90.1%, respectively. The dominant ammonia-oxidizing bacteria was the genus Nitrosomonas (0.76% abundance), and the dominant denitrifying bacteria was Thauera (0.24% abundance). The nitrite-oxidizing bacteria were not detected, confirming that the biological nitrogen removal pathway was partial nitrification and denitrification. These findings provide a feasible option for the low-carbon nitrogen removal treatment for the CADDL of municipal sludge and urban organic wastes.

原文链接:

NETL
NSTL
Taylor & Francis

Replacement depth and lifespan prediction of enhanced bioretention media under TSS impact conditions

Chunbo JiangTeng WangXijun WuZhenguo Dang...

2331-2341页

查看更多>>摘要：The enhanced bioretention system provides a new way to solve the problems of stormwater management brought by urbanization. The knowledge on effects of media modification and long-term operation is scattered, so clogging interaction function, clogging time and depth are analysed to uncover the underneath. River sand, loess, and compost were used as basic fillers, and air-dried water treatment residual (WTR) and recycled aggregate from construction waste (RACW) were used as modifiers to formulate mixed fillers, and synchronized observation of the change rule of hydraulic conductivity and porosity of vertical layering. The study found that the infiltration coefficient of each system tended to decay gradually from top to bottom as the influent TSS accumulated. A set of improved media clogging process prediction framework has been proposed, using rainfall conditions in Northwest China as input conditions, the system clogging time is about 5.5～7.1 years and the depth of replacement is about 35 cm based on the principles of cake filtration and deep filtration. The results can further understand the function variation of bioretention system under TSS impact conditions, which is helpful to the prediction of the operating life of the system and the evaluation of media replacement depth.

原文链接:

NETL
NSTL
Taylor & Francis

Replacement depth and lifespan prediction of enhanced bioretention media under TSS impact conditions

Chunbo JiangTeng WangXijun WuZhenguo Dang...

2331-2341页

查看更多>>摘要：The enhanced bioretention system provides a new way to solve the problems of stormwater management brought by urbanization. The knowledge on effects of media modification and long-term operation is scattered, so clogging interaction function, clogging time and depth are analysed to uncover the underneath. River sand, loess, and compost were used as basic fillers, and air-dried water treatment residual (WTR) and recycled aggregate from construction waste (RACW) were used as modifiers to formulate mixed fillers, and synchronized observation of the change rule of hydraulic conductivity and porosity of vertical layering. The study found that the infiltration coefficient of each system tended to decay gradually from top to bottom as the influent TSS accumulated. A set of improved media clogging process prediction framework has been proposed, using rainfall conditions in Northwest China as input conditions, the system clogging time is about 5.5～7.1 years and the depth of replacement is about 35 cm based on the principles of cake filtration and deep filtration. The results can further understand the function variation of bioretention system under TSS impact conditions, which is helpful to the prediction of the operating life of the system and the evaluation of media replacement depth.

原文链接:

NETL
NSTL
Taylor & Francis