Effect Of Quinoline On Nitrogen Removal Performance Of Continuous FlowANAMMOX System

Coal chemical wastewater is a kind of industrial wastewater that is difficult to handle and is common in the north.It contains more complex organic matter and high concentration of nitrogen in coal chemical wastewater.After pretreatment,it is generally treated by anoxic/aerobic biological process.Denitrification treatment.The Anaerobic ammonium oxidation（Anammox）process directly converts ammonia and nitrite into nitrogen under anaerobic conditions,which has the advantages of high efficiency and low consumption,and has become an emerging denitrification technology in the past decade.Since the activity of anammox bacteria is easily affected by water quality components,this study constructed an anaerobic mobile biofilm reactor to treat simulated coal chemical wastewater by a new anaerobic ammonia oxidation process.This paper mainly explores the effects of typical organic quinoline in coal chemical wastewater on the denitrification performance of continuous flow anaerobic ammonium oxidation process and recovery strategy（changing HRT,adding organic matter,adding sludge）,and analyzing the changes of microbial flora structure at each stage.The main conclusions are as follows:（1）Inhibition effect and recovery strategies of continuous quinoline addition of ANAMMOX systemAdding 20 mg/L quinoline for 10 days in the ANAMMOX system,the average removal rate of NH₄⁺-N and NO₂^--N decreased from 98.90%and 99.27%to 85.56%and 93.32%,after shutdown for 27 days and then started for 38 days,the average removal rates of NH₄⁺-N and NO₂^--N were60.34%and62.66%,andthenitrogenremovalperformancewassignificantly deteriorated.High-throughput 16S rDNA genes sequencing showed that the relative abundance of Proteobacteria increased from 23.7%to 65.8%after quinoline addition.Stop adding quinoline and prolonging HRT,the average removal rate of TN recovered to 94.65%after 3 months;the abundance values of suspended Acinetobacter and Sphingobium decreased sharply,and the later growth of Candidatus Jettenia was better than Candidatus Brodicadia.（2）Study on recovery strategies of ANAMMOX system for denitrification performance caused by activiated sludge lossThe nitrogen removal performance of the reactor can be effectively improved by adding 100mg/L of organic matter.The average removal rate of NH₄⁺-N and NO₂^--N is 84.03%and 74.61%,and the maximum TN removal rate can reach 80%,after 35 days’s operation.The off-line experiment deteriorated the peroformance of the reactor.11.86%of ANAMMOX sludge was inoculated.After 48 days,the system TN removal rate increased from 43.59%to 85.01%,and the inoculated sludge could achieve effective recovery.（3）Effect of intermittent addition of quinoline and phenol on nitrogen removal performance of ANAMMOX systemAddition of 5 mg/L or 10 mg/L quinoline did not inhibit the system removal performance.Adding 20 mg/L quinoline for 19 days,the reactor state deteriorated,stopped quinoline addition,the reactor could return to a stable state.When 50 mg/L quinoline was added for 21 days,the nitrogen removal efficiency of the reactor remained at a high level.The addition of quinoline before the domestication,so that the strong stimulation can be well adapted.After the addition of quinoline,the relative abundance of Proteobacteria increased,while the relative abundance of Bacteroidetes and Planctomycetes decreased,and the quinoline-degrading bacteria were enriched in the reactor.Addtion 20 mg/L quinoline and 50 mg/L phenol for 2 h is not affected the performance of the reactor;addtion 20 mg/L quinoline and 100 mg/L 148 h,nitrogen removal performance decrease,but it can recover effectively in 24 h.The reactor had impact resistance capability.After 20 mg/L quinoline and 200 mg/L phenol for 37 h,the reactor state deteriorated and recovered effectively after 5 days.The removal rates of NH₄⁺-N and NO₂^--N increased from 76.72%and 73.19%to96.04%and 94.34%,and the total nitrogen removal rate increased from 63.24%to 87.45%.