Studies On The Efficiency Of MBR To Remove Antibiotics From Black And Smelly Water Bodies And The Optimization Of Response Surface Methodology For Membrane Cleaning

One of the keys to treating black and smelly water bodies is to remove antibiotics from black and smelly water bodies.The serious pollution of antibiotics in black and smelly water bodies is no longer a problem in a certain area,but a common threat in many areas.Because of the large use of antibiotics in life,medical treatment and aquaculture,the task of antibiotic treatment in black and smelly water bodies is heavy.This research aims at the increasingly prominent problem of antibiotic pollution in black and smelly water bodies,referring to the relevant literature at home and abroad,summarizes the main sources,migration routes and pollution hazards of antibiotics in black and smelly water bodies,and compares and analyzes the advantages and disadvantages of the existing water environment antibiotic treatment technology.At present,the main methods used to treat antibiotics in black and smelly water bodies are sludge digestion treatment,biological method and other conventional methods,as well as more advanced membrane treatment process,ultrasonic degradation method and so on,while removing common pollutants such as chemical oxygen demand(COD)?biochemical oxygen demand(BOD),ammonia nitrogen(NH3-N),total phosphorus(TP),total nitrogen(TN),and so on.The common physical,chemical and biological methods have some shortcomings and limitations,the effect of single treatment of antibiotics is limited,and the optimization and improvement of antibiotic treatment process will also be an important research.The core technology of MBR's(membrane bioreactor)is immersed ultrafiltration technology,which is a new wastewater treatment technology which organically combines membrane separation technology with biological treatment technology,also known as membrane separation activated sludge process.It uses membrane separation equipment to intercept and retain activated sludge and macromolecular organic matter in biochemical reaction tanks.Hydraulic retention time and sludge retention time can be controlled separately,while refractory substances constantly react and degrade in the reactor.In this study,four commonly used antibiotics were selected as the target detection substances.Through the detection and analysis of the water quality characteristics of black and smelly water bodies,the water for artificial simulation experiment was used.Two groups of reactor 1 and reactor 2 were set up at the same time.Under the premise of ensuring the same operation conditions,the water quality of the two reactors in the simulation experiment was low COD(300 mg/L)and high COD(600 mg/L)was set as a stage for 30 days,and the concentration of antibiotics in the influent was gradually increased.Ultrasonic extraction,solid-phase extraction and ultra-performance liquid chromatography-mass spectrum-mass spectrum were used to investigate the influence of antibiotic concentration and species on MBR operation and the removal effect of antibiotics.The experimental results show that in the black and smelly water bodies containing typical antibiotics,the removal of conventional detection substances by MBR mainly depends on the biodegradation of activated sludge,and the removal of antibiotics mainly depends on membrane separation.The adsorption and biodegradation of antibiotics by activated sludge are limited.The removal efficiency of erythromycin(ERY)and tetracycline(TC)was not affected by the change of organic matter concentration.The removal efficiency of sulfamethoxazole(SMX)decreased slightly in the high concentration organic matter environment.The removal efficiency of norfloxacin(NOR)was higher in the high concentration organic matter environment.ERY has a certain degree of hydrolysis,which is less affected by antibiotic concentration;SMX gradually adapts to and maintains high removal rate after being affected by high concentration of antibiotics;NOR mainly focuses on the adsorption of activated sludge,which is mainly retained in sludge;TC mainly focuses on hydrolysis and sludge adsorption,which is not affected by the change of antibiotic concentrationIn the study of the chemical cleaning process of the polluted ultrafiltration membrane module,the removal rate of irreversible resistance was used to characterize the chemical cleaning efficiency of ultrafiltration membrane.The response surface model was used to investigate the influence of three factors,namely sodium hypochlorite concentration,citric acid concentration and chemical cleaning time,and the interaction of the combination of factors was discussed to optimize the chemical cleaning process.The interaction between the concentration level of sodium hypochlorite and the time level of chemical cleaning had the most significant effect on the chemical cleaning effect of ultrafiltration membrane.The chemical cleaning efficiency increased with the increase of the control level of both.Under the condition of high efficiency of chemical cleaning and service life of membrane,a more economical combination scheme is selected.It provides theoretical basis for the application of MBR integrated process in the purification of black and smelly water bodies,and has important reference value for the selection of water purification process and the improvement of wastewater treatment efficiency.