| Wastewater is rich in organic matter,and the recovery of biomass energy is of great significance for solving water pollution and energy crisis.The anaerobic forward osmosis membrane bioreactor（AnOMBR）can effectively trap microorganisms and dissolved methane in the effluent.The biomass energy recovery effect is good,but the ammonia nitrogen removal effect is not good,which has caused concern.The electrochemical oxidation of ammonia nitrogen can convert ammonia nitrogen into nitrogen through direct oxidation and indirect oxidation of the electrode,with high removal efficiency and few by-products,but high chloride ion concentration environmental conditions are required.This thesis combines electrochemical oxidation and AnOMBR to form an electrochemical oxidation-anaerobic forward osmosis membrane bioreactor（EO-AnOMBR）,using sodium chloride as the forward osmosis draw solution,and using ruthenium-iridium-tin ternary coating on the draw solution side The oxide-coated titanium metal mesh（Ti/RuO2-IrO2-SnO2 electrode）is the anode,and the SS306 stainless steel mesh is the cathode,which improves the ammonia nitrogen removal efficiency in situ,studies the ammonia nitrogen removal mechanism,and discusses the electrochemical oxidation and anaerobic forward osmosis membrane biology Coupling between reactors.This research mainly involves the following two aspects:（1）Investigate the effect of different parameter conditions on the process of electrochemical oxidation removal of ammonia nitrogen,and discuss the production of residual chlorine by-product.The experimental results show that the greater the current density,the faster the ammonia nitrogen removal,the higher the current efficiency,and the more residual chlorine.The larger the electrode plate spacing,the higher the energy consumption.When the electrode plate spacing is 5 mm,the average energy consumption is the lowest,which is 0.025 Wh/g（NH4+-N）.The higher the initial chloride ion concentration,the faster the ammonia nitrogen removal and the higher the current efficiency.The average current efficiency at 0.5 M NaCl is 61.12%.The lowest point of combined residual chlorine is the"electrochemical break point",at which point ammonia nitrogen is completely removed,and the residual chlorine of the by-product is the least.（2）Examine and compare the performance of EO-AnOMBR and AnOMBR in terms of membrane flux,permeation,pollutant removal,gas production,etc.Analyze the effect of coupled electrochemical oxidation on the feed solution side of the bioreactor.The experimental results show that EO-AnOMBR has better effluent water quality than AnOMBR,and the removal rate of ammonia nitrogen in the effluent can reach 97.9%on average（AnOMBR is only 70.4%）.Throughout the experimental period,the initial water flux of the EO-AnOMBR forward osmosis membrane increased by about 7.4%.Both the conductivity and pH in the reactor showed an increasing trend,and the change trend of volatile fatty acid content first increased and then decreased,and did not accumulate in the reactor,indicating that it was effectively bio-utilized.The EO-AnOMBR system has a high pollutant removal rate,with an average COD removal rate of 94.8%and an average phosphate removal rate of99.6%.The introduction of an electric field did not affect the activity of the biological unit.The maximum methane output of EO-AnOMBR is 0.25 L/gCOD. |
