The short-and long-term effects of chlortetracycline（CTC） on the nitritation-anaerobic ammonium oxidation（anammox） process were evaluated. The half maximal inhibitory concentration of CTC in the batch tests of the...The short-and long-term effects of chlortetracycline（CTC） on the nitritation-anaerobic ammonium oxidation（anammox） process were evaluated. The half maximal inhibitory concentration of CTC in the batch tests of the nitritation-anammox process was 278.91 mg/L at an exposure time of 12 hr. The long-term effects of CTC on the process were examined in a continuous-flow nitritation-anammox reactor. Within 14 days, the nitrogen removal rate significantly decreased from 0.61 to 0.25 kg N/m^3/day with 60 mg/L CTC in the influent.The performance suppressed by CTC barely recovered, even after CTC was removed from the influent. Furthermore, the inhibition of CTC also reduced the relative abundance of ammonium oxidizing bacteria（AOB） and anaerobic ammonium oxidizing bacteria（An AOB）in the reactor, resulting in both a decreased amount of and an imbalance between AOB and An AOB. When fresh anammox sludge was reseeded into the nitritation-anammox reactor,the nitrogen removal rate recovered to 0.09 ± 0.03 kg N/m3/day.展开更多
This study investigated the role of biochar in enhancing nitrogen removal efficiency(NRE)and stability in partial nitrification-anammox(PN/A)systems,focusing on its selective promotion of partial denitrification and m...This study investigated the role of biochar in enhancing nitrogen removal efficiency(NRE)and stability in partial nitrification-anammox(PN/A)systems,focusing on its selective promotion of partial denitrification and maintaining the dynamic balance between AnAOB and denitrifying bacteria(DNB).The results showed that biochar enhances electron transfer,effectively reduced nitrate accumulation and significantly improved PN/A system NRE and stability.Under high ammonium conditions(800 mg/L),biochar increased NRE in the PN/A system to 83.58%,a 10% improvement over the anammox-control(A_(CK)).Additionally,partial denitrification contributed 8% more to total nitrogen removal in the anammox-biochar(A_(BC))system.The porous structure and redox-active groups of biochar provided an ideal environment for key microorganisms,promoted microbial growth and increased specific anammox activity by approximately 1.25-1.46 times compared to ACK,further enhancing microbial stability under fluctuating nitrogen loads.Biochar also enriched AnAOB and DNB communities,sustained their dynamic balance and improved system stability by promoting nitrogen removal related gene expression.Overall,biochar demonstrated great potential for improving PN/A system efficiency,optimizing wastewater treatment,and reducing energy consumption and emissions.展开更多
基金supported by the National Natural Science Foundation of China (No. 51578043)the Basic research funds (No. C16JB00480)
文摘The short-and long-term effects of chlortetracycline（CTC） on the nitritation-anaerobic ammonium oxidation（anammox） process were evaluated. The half maximal inhibitory concentration of CTC in the batch tests of the nitritation-anammox process was 278.91 mg/L at an exposure time of 12 hr. The long-term effects of CTC on the process were examined in a continuous-flow nitritation-anammox reactor. Within 14 days, the nitrogen removal rate significantly decreased from 0.61 to 0.25 kg N/m^3/day with 60 mg/L CTC in the influent.The performance suppressed by CTC barely recovered, even after CTC was removed from the influent. Furthermore, the inhibition of CTC also reduced the relative abundance of ammonium oxidizing bacteria（AOB） and anaerobic ammonium oxidizing bacteria（An AOB）in the reactor, resulting in both a decreased amount of and an imbalance between AOB and An AOB. When fresh anammox sludge was reseeded into the nitritation-anammox reactor,the nitrogen removal rate recovered to 0.09 ± 0.03 kg N/m3/day.
基金founded by the National Natural Science Foundation of China(No.52270049)the Shaanxi Youth Star Program for Science and Technology,China(No.2023KJXX-042).
文摘This study investigated the role of biochar in enhancing nitrogen removal efficiency(NRE)and stability in partial nitrification-anammox(PN/A)systems,focusing on its selective promotion of partial denitrification and maintaining the dynamic balance between AnAOB and denitrifying bacteria(DNB).The results showed that biochar enhances electron transfer,effectively reduced nitrate accumulation and significantly improved PN/A system NRE and stability.Under high ammonium conditions(800 mg/L),biochar increased NRE in the PN/A system to 83.58%,a 10% improvement over the anammox-control(A_(CK)).Additionally,partial denitrification contributed 8% more to total nitrogen removal in the anammox-biochar(A_(BC))system.The porous structure and redox-active groups of biochar provided an ideal environment for key microorganisms,promoted microbial growth and increased specific anammox activity by approximately 1.25-1.46 times compared to ACK,further enhancing microbial stability under fluctuating nitrogen loads.Biochar also enriched AnAOB and DNB communities,sustained their dynamic balance and improved system stability by promoting nitrogen removal related gene expression.Overall,biochar demonstrated great potential for improving PN/A system efficiency,optimizing wastewater treatment,and reducing energy consumption and emissions.
