Efficiency Of Nitrogen Multistage A/O Biofilm Process Low COD Sewage

Low COD concentration in Municipal Wastewater is a key factor which affects the treatment efficiency of wastewater biological nitrogen removal. Southern sewage COD concentration is low. Due to a low nutritional status, the sludge growth is slow, Running efficiency is mainly influenced by the speed of sludge growth leading to lack of biomass. The utilization of carbon source is too low to denitrification.; and effective utilization rate of the carbon source, resulting in insufficient denitrification, nitrogen removal is poor. Firstly, to strengthen through domestication biofilm nitrification and denitrification biofilm start efficiency multi-stage A / O Biofilm processes and regulation of process parameters, optimization of water effects, and finally through the analysis of high-throughput sequencing technology biofilm reactor fast start-up and commissioning function of stable operation. The reactor to be solved for low COD removal effect of poor sewage problem.Experiments with water by increasing the nitrogen and carbon sources, gradient domesticated biofilm nitrification and denitrification biofilm system. System has been domesticated completed in 20 days. The use of domesticated biofilm nitrification and denitrification systems biofilm systems were analog low COD of domestic sewage treatment, nitrification biofilm system of ammonia and TN removal rate were 99% and 50%; Both nitrate denitrifying bio film N and TN removal were 99%.Run multipole A / O biofilm reactor, contrast Bioaugmentation start mode and natural way to start on the start discovery efficiency, shorten the 16 days after bioaugmentation reactor, it can never strengthen its startup cycl e time up to 7 days. Comparison of different operating parameters to determine the optimal operating conditions are: water residence time of 8 h, influent flow distribution ratio of 2: 1, nitrification liquid reflux ratio is 200%. In this situation, efflue nt COD, ammonia and TN were 20 mg / L, 0.1 mg / L and 8.5 mg / L, the removal rate were 83%, 99% and 58% can be achieved national urban sewage A standard.High-throughput sequencing technology for multi-stage A / O Biofilm Reactor samples of each functional block microbial community structure parsing, A / O Process O segment and nitrification in biofilm bacteria species similar to the existing system, nitrification biofilms having the function of nitrification of dominant bacteria(Nitrosomonadaceae_uncultured and Nitrospira) after the input a / O reactor and stable operation, still dominant, bioaugmentation success. A / O process in the A segment with denitrification biofilm system similar to the original flora species, nitrification biofilm nitrification f unction has the advantage of flora(Thauera, Flavobacterium and Pseudomonas) into the A / O reactor and stable operation later, still dominates, bioaugmentation success system having denitrification capability flora bacteria belonging to the advantages and strengthen the effectiveness of the denitrification treatment system.