Adsorption And Degradation Of Sulfadimethoxine In Biological Treatment System Of Livestock And Poultry Breeding Wastewater

In recent years,with the rapid development of livestock and poultry husbandry,the abuse of antibiotics in the aquaculture industry has triggered a series of human health problems.It has alerted the world to the health problems caused by livestock and poultry farming wastewater,and has taken corresponding measures to solve the problem actively.This paper explored the migration and conversion of sulfadimethoxine in livestock wastewater treatment systems,studied the adsorption,degradation of sulfadimethoxine in sludge,and the effect on the wastewater treatment reactor.The experimental results were as follows:(1)The self-hydrolysis stability of SDM was studied.SDM had a small amount of photolysis in the water environment.Temperature and p H had little effect on the hydrolysis of SDM in aqueous environments.(2)The adsorption of different initial concentrations of SDM in inactivated anaerobic granular sludge and inactivated aerobic floccular sludge was studied.The adsorption of deactivated anaerobic granular sludge to different initial concentrations of SDM basically reached equilibrium at 8 hours,and the adsorption of inactivated aerobic flocculent sludge to different initial concentrations of SDM basically reached equilibrium at 6 h.Inactivated anaerobic granules and inactivated aerobic granules Under the conditions of alkaline conditions,the inactivation of anaerobic granules and inactivated aerobic granules have a stronger adsorption capacity for SDM.(3)Adsorption isotherms of inactivated anaerobic granular sludge and inactivated aerobic floccular sludge.When the temperature was in the range of 15 to 35°C,the Freundlich fitted to the SDM adsorption data of two inactivated sludges was more suitable to the Langmuir fitted to the SDM adsorption data,as known from RF2>RL2,RF2>0.99.The adsorption of SDM by two kinds of sludge is not a simple monolayer adsorption but a combination of surface adsorption and multilayer adsorption.Adsorption constant KF(15°C)>KF(25°C)>KF(35°C),the capacity of SDM adsorption on sludge decreases with increasing temperature.The adsorption of SDM on two kinds of sludge is an exothermic reaction.Sludge has a certain influence on the initial equilibrium SDM adsorption equilibrium time.The greater the initial concentration of SDM,the longer adsorption time of the aerobic activated sludge and anaerobic granular sludge on the SDM adsorption in the water environment reaches the adsorption equilibrium.(4)The initial concentration of SDM is 20 mg/L.At 15°C~35°C,the adsorption capacity of anaerobic granular sludge and aerobic flocculated sludge to SDM in water environment is much greater than that to water.SDM degradation in the environment,sludge adsorption is the most important part of the removal of SDM.At p H 5-9,the adsorption capacity of active anaerobic granules and active aerobic granules to SDM in water environment is much larger than that of SDM in water environment.Sludge adsorption is removed.The most important part of SDM.(5)The influence of SDM in livestock and poultry breeding wastewater on COD removal by UASB reactor.When the concentration of SDM in anaerobic granular sludge reaches 3.14 mg/g,the removal of COD in UASB reactor pair has a significant downward trend.When the concentration of SDM in anaerobic granular sludge was 5.46 mg/g,the activity of anaerobic microorganisms reached a minimum.(6)The effect of SDM in livestock and poultry breeding wastewater on COD removal by SBR reactor.When the amount of SDM in aerobic floc sludge is 1.56 mg/g,the removal efficiency of COD by SBR reactor is significantly reduced.When the amount of SDM in the aerobic flocculent sludge was 6.17 mg/g,the aerobic microorganism activity reached a minimum.