Basic Study On The Application Of Galvanic Cell Coupling A/O-MBR To The Treatment Of Antibiotics In Livestock And Poultry Breeding Wastewater

Antibiotics in livestock and poultry breeding wastewater are one of the main sources of antibiotic contamination in water.The wastewater containing antibiotics will enter the ecosystem through the water cycle,thus threatening human health.The establishment of a set of water purification technology that can effectively treat antibiotics-containing wastewater is the key to controlling antibiotic pollution from the root.In this paper,wastewater was treated through an integrated system,namely a galvanic cell and an A/O-MBR,verifying its effectiveness.The single-factor test method was used to analyze the optimum operation conditions of the process.Laboratory simulation test was performed to detect the effect of tetracycline hydrochloride?TC-HCl?,norfloxacin?NOR?and sulfisoxazole?SIZ?on the decontamination ability of the integrated system.Finally,the main methods to systematically remove antibiotics were discussed.Researches indicate as follows:?1?The system's decontamination efficiency is the best,with the following conditions,including 24 hours system HRT,16 L·min^-11 aeration intensity,polyurethane sponge filler,and 8.5-9.5 pH,750 mg·L^-11 COD,25 mg·L^-11 NH₃-N and 5 mg·L^-11 TP respectively in the inlet water.Under the optimal condition of integration,the system's removal rates of COD,NH₃-N and TP are 95.35%,97.08%and 86.97%,respectively.The effluent water quality meets the water quality standards of Level A in the Pollutant Discharge Standard for Urban Sewage Treatment Plants.Coupling MBR process can significantly improve the decontamination efficiency of traditional A/O process on COD,NH₃-N and TP.Compared with the traditional A/O-MBR process,the galvanic cell coupling A/O-MBR process not only has better efficiency to remove biological phosphorus,but also prolongs the membrane fouling cycle from about 17 d up to about 24 d,effectively delaying membrane fouling.?2?Under the optimal processing integration condition,the treatment effect of the galvanic cell coupling A/O-MBR process on the three types of antibiotics is:TC-HCl>NOR>SIZ.When the initial concentration of antibiotics is 30 mg·L^-1,the removal efficiency of TC-HCl,NOR and SIZ are 88.88%,67.02%and 22.76%,respectively.Different from the control group,when the concentrations of TC-HCl,NOR and SIZ are 30 mg·L^-1,the removal efficiency of COD is reduced by 8.85%,5.94%,7.07%,respectively,NH₃-N decreased by13.38%,6.58%,32.02%,respectively and TP declined by 3.97%,12.40%,and 45.13%,respectively.TC-HCl,NOR and SIZ are toxic pollutants that can be degraded by microorganisms.Therefore,these three antibiotics in wastewater significantly affect the main technical indicators of wastewater treatment.?3?The complex substance composition,temperature and light in the wastewater can accelerate the degradation of TC-HCl,NOR and SIZ in the water to a certain extent.The higher the initial concentration is,the more stable the antibiotics are.The stability of NOR and SIZ are better,while the stability of TC-HCl is poor.The higher initial mass concentration of antibiotics stands for the higher unit adsorption capacity of sludge.The higher concentration of sludge means the larger capacity of total adsorption and smaller unit adsorption capacity.Acidic conditions are conducive to the adsorption of NOR and SIZ,and alkaline conditions are helpful to the adsorption of TC-HCl.The adsorption of TC-HCl by sludge at elevated temperature increases,while the adsorption of NOR and SIZ decreases.The adsorption of the three antibiotics can be spontaneous,and the process conforms to the pseudo second-order kinetic equation.The sludge adsorption equilibrium process of TC-HCl and NOR is more in line with Freundlich model,and the adsorption equilibrium process of SIZ is more close to Langmuir model.The process of sludge adsorption of TC-HCl is endothermic and entropy increases,while the process of adsorption of NOR is exothermic and entropy decreases,and the process of adsorption of SIZ is exothermic and entropy increases.The removal of NOR and SIZ in wastewater by the galvanic cell coupling A/O-MBR process mainly depends on the adsorption of sludge and the degradation of microorganisms.The removal of TC-HCl can be achieved by self-hydrolysis,sludge adsorption and microbial degradation.