Eutrophication caused by high concentrations of nutrients is a huge problem for many natural lakes and reservoirs. Removing the nitrogen contamination from the low C/N water body has become an urgent need. Autotrophic...Eutrophication caused by high concentrations of nutrients is a huge problem for many natural lakes and reservoirs. Removing the nitrogen contamination from the low C/N water body has become an urgent need. Autotrophic denitrification with the sulfur compound as electron donor was investigated in the biofilter reactors. Through the lab-scale experiment,it was found that different sulfur compounds and different carriers caused very different treatment performances. Thiosulfate was selected to be the best electron donor and ceramsite was chosen as the suitable carrier due to the good denitrification efficiency, low cost and the good resistibility against the high hydraulic loads. Later the optimum running parameters of the process were determined. Then the pilot-scale experiment was carried out with the real micro-polluted water from the West Lake, China. The results indicated that the autotrophic denitrification with thiosulfate as electron donor was feasible and applicable for the micro-polluted lake water.展开更多
Rapid formation of autotrophic partial denitrification(APD)granules is of practical interest to start up an expanded granular sludge bed reactor for wastewater treatment.This study demonstrates that methanogenic granu...Rapid formation of autotrophic partial denitrification(APD)granules is of practical interest to start up an expanded granular sludge bed reactor for wastewater treatment.This study demonstrates that methanogenic granules can be easily acclimated into autotrophic partial denitrification granules in one day,with the ability to remove 82%of 2.7 kg-S/(m^3·d)sulfide into S^0 and to convert 97%of 0.9 kg-N/(m^3·d)nitrate into nitrite,which can provide a promising feedstock for anaerobic ammonia oxidation process.Arcobacter sp.is essential for S^0 accumulation.Under high loadings,the abundance of Arcobacter sp.decreased,while on the contrary the abundance of unclassified_p_Firmicutes increased,leading to the deterioration of autotrophic partial denitrification performance.The granules performance could be recovered by adopting the strategies of properly reducing the influent loadings.展开更多
Nitrate is considered to be one of the most widely present pollutants leading to eutrophication of environment. The purpose of this work was to isolate and identify new anaerobic denitrifying bacteria from reservoir s...Nitrate is considered to be one of the most widely present pollutants leading to eutrophication of environment. The purpose of this work was to isolate and identify new anaerobic denitrifying bacteria from reservoir sediments and utilize different electron donors for isolates to improve nitrate removal efficiency. Using traditional enrichment approach,one purified anaerobic bacterium( Y12) capable of NO-3-N removal from sediments was obtained. The species identity of Y12 was determined via 16 S rRNA gene sequence analysis to be Acinetobacter. In this work,the fastest denitrification rates were observed with ferrous iron as electron donor.And,slightly slower rates were observed with hydrogen and sodium sulfide as electron donors. However,when used hydrogen gas, ferrous iron and sodium sulfide as electron donors, C / N ratios had little effect on autotrophic denitrification rate at the initial C / N ratio from 1.5 to 9.0. Meanwhile,when made use of hydrogen gas,ferrous iron and sodium sulfide as electron donors,a maximum nitrate removal ratio of 100.00%,91.43%and 87.99% at the temperature of 30 ℃,respectively. Moreover,maximum denitrification activity was observed at p H 6.0-7.0.展开更多
The removal of eight typical pharmaceuticals(Ph ACs)(i.e.,ibuprofen(IBU),ketoprofen(KET),diclofenac(DIC),sulfadiazine(SD),sulfamethoxazole(SMX),trimethoprim(TMP),ciprofloxacin(CIP)and enoxacin(ENO))in sulfur-driven au...The removal of eight typical pharmaceuticals(Ph ACs)(i.e.,ibuprofen(IBU),ketoprofen(KET),diclofenac(DIC),sulfadiazine(SD),sulfamethoxazole(SMX),trimethoprim(TMP),ciprofloxacin(CIP)and enoxacin(ENO))in sulfur-driven autotrophic denitrification(Sd AD)process were firstly investigated via long-term operation of bioreactor coupled with batch tests.The results indicated that IBU and KET can be effectively removed(removal efficiency>50%)compared to other six Ph ACs in Sd AD bioreactor.Biodegradation was the primary removal route for IBU and KET with the specific biodegradation rates of 5.3±0.718.1±1.8μg g ^(-1)-VSS d ^(-1)at initial concentrations of 25-200μg/L.The biotransformation intermediates of IBU and KET were examined,and the results indicated that IBU was biotransformed to three intermediates via hydroxylation and carboxylation.KET biotransformation could be initiated from the reduction of the keto group following with a series of oxidation/reduction reactions,and five intermediates of KET were observed in this study.The microbial community composition in the system was markedly shifted when long-term exposure to Ph ACs.However,the functional microbes(e.g.,genus Thiobacillus)showed high tolerance to Ph ACs,resulting in the high efficiency for Ph ACs,N and S removal during long-term Sd AD reactor operation.The findings provide better insight into Ph ACs removal in Sd AD process,especially IBU and KET,and open up an innovative opportunity for the treatment of Ph ACs-laden wastewater using sulfur-mediated biological process.展开更多
Sulfur-limestone was used in the autotrophic denitrification process to remove the nitrate and nitrite in a lab scale upflow biofilter.Synthetic water with four levels of nitrate and nitrite concentrations of 10,40,70...Sulfur-limestone was used in the autotrophic denitrification process to remove the nitrate and nitrite in a lab scale upflow biofilter.Synthetic water with four levels of nitrate and nitrite concentrations of 10,40,70 and 100 mg N/L was tested.When treating the low concentration of nitrate-or nitrite-contaminated water（10,40 mg N/L）,a high removal rate of about 90% was achieved at the hydraulic retention time（HRT） of 3 hr and temperature of 20-25°C.At the same HRT,50% of the nitrate or nitrite could be removed even at the low temperature of 5-10°C.For the higher concentration nitrate and nitrite（70,100 mg N/L）,longer HRT was required.The batch test indicated that influent concentration,HRT and temperature are important factors afiecting the denitrification eficiency.Molecular analysis implied that nitrate and nitrite were denitrified into nitrogen by the same microorganisms.The sequential two-step-reactions from nitrate to nitrite and from nitrite to the next-step product might have taken place in the same cell during the autotrophic denitrification process.展开更多
基金supported by the National Natural Science Foundation of China (No. 51478262)The Chinese National Key Projects of Water Pollution Control and Reclamation (No. 2012ZX07101-007-005)the Open Fund Project of Zhejiang Mariculture Research Institute (No. J2013005)
文摘Eutrophication caused by high concentrations of nutrients is a huge problem for many natural lakes and reservoirs. Removing the nitrogen contamination from the low C/N water body has become an urgent need. Autotrophic denitrification with the sulfur compound as electron donor was investigated in the biofilter reactors. Through the lab-scale experiment,it was found that different sulfur compounds and different carriers caused very different treatment performances. Thiosulfate was selected to be the best electron donor and ceramsite was chosen as the suitable carrier due to the good denitrification efficiency, low cost and the good resistibility against the high hydraulic loads. Later the optimum running parameters of the process were determined. Then the pilot-scale experiment was carried out with the real micro-polluted water from the West Lake, China. The results indicated that the autotrophic denitrification with thiosulfate as electron donor was feasible and applicable for the micro-polluted lake water.
基金supported by the National Natural Science Foundation of China (21307160)the Natural Science Foundation of Shandong Province, China (ZR20192019MEE038)+3 种基金the Fundamental Research Funds for the Central Universities (19CX02038A)the Open Project of Key Laboratory of Environmental Biotechnology, CAS (Grant No. kf2018003)the Open Project Program of State Key Laboratory of Petroleum Pollution Control (Grant No. PPC2018006)the CNPC Research Institute of Safety and Environmental Technology
文摘Rapid formation of autotrophic partial denitrification(APD)granules is of practical interest to start up an expanded granular sludge bed reactor for wastewater treatment.This study demonstrates that methanogenic granules can be easily acclimated into autotrophic partial denitrification granules in one day,with the ability to remove 82%of 2.7 kg-S/(m^3·d)sulfide into S^0 and to convert 97%of 0.9 kg-N/(m^3·d)nitrate into nitrite,which can provide a promising feedstock for anaerobic ammonia oxidation process.Arcobacter sp.is essential for S^0 accumulation.Under high loadings,the abundance of Arcobacter sp.decreased,while on the contrary the abundance of unclassified_p_Firmicutes increased,leading to the deterioration of autotrophic partial denitrification performance.The granules performance could be recovered by adopting the strategies of properly reducing the influent loadings.
基金Sponsored by the National Key Technology Research and Development Program of the Ministry of Science and Technology of China(Grant No.2012BAC04B02)Open Project of State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(Grant No.QA201518)the Key Laboratory of the Education Department of Shaanxi Province(Grant No.12JS051)
文摘Nitrate is considered to be one of the most widely present pollutants leading to eutrophication of environment. The purpose of this work was to isolate and identify new anaerobic denitrifying bacteria from reservoir sediments and utilize different electron donors for isolates to improve nitrate removal efficiency. Using traditional enrichment approach,one purified anaerobic bacterium( Y12) capable of NO-3-N removal from sediments was obtained. The species identity of Y12 was determined via 16 S rRNA gene sequence analysis to be Acinetobacter. In this work,the fastest denitrification rates were observed with ferrous iron as electron donor.And,slightly slower rates were observed with hydrogen and sodium sulfide as electron donors. However,when used hydrogen gas, ferrous iron and sodium sulfide as electron donors, C / N ratios had little effect on autotrophic denitrification rate at the initial C / N ratio from 1.5 to 9.0. Meanwhile,when made use of hydrogen gas,ferrous iron and sodium sulfide as electron donors,a maximum nitrate removal ratio of 100.00%,91.43%and 87.99% at the temperature of 30 ℃,respectively. Moreover,maximum denitrification activity was observed at p H 6.0-7.0.
基金supported by the National Natural Science Foundation of China(Nos.52000186,51922110 and 52131001)。
文摘The removal of eight typical pharmaceuticals(Ph ACs)(i.e.,ibuprofen(IBU),ketoprofen(KET),diclofenac(DIC),sulfadiazine(SD),sulfamethoxazole(SMX),trimethoprim(TMP),ciprofloxacin(CIP)and enoxacin(ENO))in sulfur-driven autotrophic denitrification(Sd AD)process were firstly investigated via long-term operation of bioreactor coupled with batch tests.The results indicated that IBU and KET can be effectively removed(removal efficiency>50%)compared to other six Ph ACs in Sd AD bioreactor.Biodegradation was the primary removal route for IBU and KET with the specific biodegradation rates of 5.3±0.718.1±1.8μg g ^(-1)-VSS d ^(-1)at initial concentrations of 25-200μg/L.The biotransformation intermediates of IBU and KET were examined,and the results indicated that IBU was biotransformed to three intermediates via hydroxylation and carboxylation.KET biotransformation could be initiated from the reduction of the keto group following with a series of oxidation/reduction reactions,and five intermediates of KET were observed in this study.The microbial community composition in the system was markedly shifted when long-term exposure to Ph ACs.However,the functional microbes(e.g.,genus Thiobacillus)showed high tolerance to Ph ACs,resulting in the high efficiency for Ph ACs,N and S removal during long-term Sd AD reactor operation.The findings provide better insight into Ph ACs removal in Sd AD process,especially IBU and KET,and open up an innovative opportunity for the treatment of Ph ACs-laden wastewater using sulfur-mediated biological process.
基金supported by the National Natural Science Foundation of China(No.50808121)the Chinese National Key Projects of Water Pollution Control and Reclamation(No.2008ZX07106-2-2)
文摘Sulfur-limestone was used in the autotrophic denitrification process to remove the nitrate and nitrite in a lab scale upflow biofilter.Synthetic water with four levels of nitrate and nitrite concentrations of 10,40,70 and 100 mg N/L was tested.When treating the low concentration of nitrate-or nitrite-contaminated water（10,40 mg N/L）,a high removal rate of about 90% was achieved at the hydraulic retention time（HRT） of 3 hr and temperature of 20-25°C.At the same HRT,50% of the nitrate or nitrite could be removed even at the low temperature of 5-10°C.For the higher concentration nitrate and nitrite（70,100 mg N/L）,longer HRT was required.The batch test indicated that influent concentration,HRT and temperature are important factors afiecting the denitrification eficiency.Molecular analysis implied that nitrate and nitrite were denitrified into nitrogen by the same microorganisms.The sequential two-step-reactions from nitrate to nitrite and from nitrite to the next-step product might have taken place in the same cell during the autotrophic denitrification process.
