Study On Adsorption And Degradation Of Ciprofloxacin On The Anaerobic And Aerobic Activated Sludge

Large-scale aquaculture farming density,as a feed additive,antibiotics are concentrated and widely used,a large number of antibiotics in the wastewater have not been effectively treated into the environment,will lead to serious antibiotic pollution.Piggery wastewater treatment facilities play an important role in removing antibiotics from wastewater,and are also affected by antibiotics.In this paper,the adsorption degradation behavior of ciprofloxacin in anaerobic and aerobic activated sludge and the effect of ciprofloxacin on the activated sludge in aerobic reactor were studied,and to provide a theoretical reference for reducing the impact of antibiotics on pig farming wastewater treatment process.Research indicates:The adsorption and degradation of two kinds of sludge on CIP:In this paper,the adsorption of CIP by two kinds of inactivated sludge was studied,and the adsorption of ciprofloxacin by two kinds of activated sludge was studied.The results of the study show that:The adsorption of the inactivated sludge on the CIP is a rapid process,the adsorption rate is that‘inactivated anaerobic sludge>inactivated aerobic sludge'.A certain concentration of ciprofloxacin,The higher the MLSS,the more adsorption sites to adsorb CIP,the higher the adsorption capacity,the shorter the adsorption equilibrium;MLSS was 1500 mg/L,inactivated sludge basically reached adsorption equilibrium after 30 min,the adsorption rate is about 95%;MLSS was1000 mg/L,inactivated sludge reached adsorption equilibrium after 2 hours,the adsorption rate is about 85%;MLSS was 500 mg/L,inactivated sludge reached adsorption equilibrium after 10 hours,the adsorption rate is about 50%.The temperature can affect the adsorption of CIP by inactivated sludge,low temperature is beneficial to the progress of the reaction.The adsorption of CIP by inactivated anaerobic sludge is well fitted to the Freundlich and Langmuir equations?R_F²>0.95,R_L²>0.99?,which Langmuir equation is better fit?R_L²>R_F²?,the Freundlich equation is more suitable for the adsorption of CIP than the Langmuir equation,the adsorption behavior of inactivated aerobic sludge on CIP is complex,not a simple surface adsorption;adsorption of CIP by inactivated anaerobic sludge was dominated by monolayer adsorption,multi-layer adsorption at the same time.At experimental condition,MLSS was 1000 mg/L,CIP at a concentration of 20 mg/L condition,the adsorption capacity of anaerobic activated sludge to CIP was 16.302 mg/g,the adsorption rate was 81.5%,the degradation capacity was 2.31 mg/g,the biodegradability rate was11.54%;the adsorption capacity of aerobic activated sludge to CIP was 17.38 mg/g,the adsorption rate was 86.9%,the degradation capacity was 2.41 mg/g,the biodegradability rate was 12.1%.Therefore,the removal of CIP in two kinds of activated sludge is mainly composed of adsorption,adsorption and biodegradation,the degradation efficiency of aerobic activated sludge is higher than anaerobic activated sludge.The effect of COD_Cr removal efficiency on the SBR reactor by CIP:Experimental conditions at room temperature,waste water containing CIP at a concentration of 20 mg/L,when the effect of the concentration of CIP aerobic activated sludge reaches 12.52 mg/g,COD_Cr removal rate fell to about 4.4%,SBR reactor substantially lost the ability to remove pollutants of waste water.The results of microscopic examination of activated sludge in aerobic reactors which were continuously affected by CIP shown out that,under normal temperature conditions,the density of filamentous bacteria in the experimental group was greater than that in the control group,indicating that the concentration of 20 mg/L CIP under the action,the filamentous bacteria were not significantly inhibited,and the growth is good.Under the influence of CIP,the structure of the zooglea is loosened by the compact.Experiments show that a filamentous fungus can produce resistance to CIP,and grown under high concentrations of CIP.The filamentous bacteria were resistant to certain concentrations of CIP and also play a major role in the microbial degradation of CIP.Treatment of CIP concentration of 5mg/L wastewater aerobic reactor recovery speed,about a week to restore normal processing capacity,COD_Cr removal rate of about 78%;after the SBR reactor treated with CIP at a concentration of 10 mg/L was returned to stable operation,COD_Cr removal rate of about 60%;after the SBR reactor treated with CIP at a concentration of 20 mg/L was returned to stable operation,COD_Cr removal rate of about 20%.