Study On Removal Performance Of Emerging Pollutants In Micro-polluted Water By Biological Oxidation Process

Emerging pollutants are widely found in natural waters.Due to its low content,its purification efficiency in traditional water treatment processes is very limited.These organic pollutants enter the human body through the enrichment of drinking water and the food chain,which will cause a series of health risks.In this study,an integrated bioprecipitation device developed by the research group is used to select representative emerging pollutants,sulfamethoxazole(SMX)and carbamazepine(CBZ),as the treatment targets.The removal performance of emerging organic pollutants reveals the degradation kinetics and biochemical enhancement removal mechanism of SMX and CBZ.The main research results are as follows:(1)The device has obvious degradation effect on micro-polluted water source containing antibiotics,and under the condition of hydraulic load 0.064 m~3/(m~2?d),the removal effect of sulfamethoxazole is the best,reaching 83.9%.Increasing or reducing the hydraulic load is not conducive to its removal.Under the condition of hydraulic load of 0.051 m~3/(m~2?d),the system had the best effect of removing carbamazepine,reaching67.3%.The weak alkaline environment facilitated the simultaneous removal of sulfamethoxazole and carbamazepine,and the removal rates were 82%and 53.6%,respectively.The biodegradation pathway of sulfamethoxazole in this system is mainly due to the heterotrophic bacteria and autotrophic nitrifying bacteria that prefer the target pollutants.The biooxidation process of carbamazepine relies mainly on co-degradation in the degradation of organic compounds.(2)The change of organic loading of the device obviously affects the removal effect of sulfamethoxazole and carbamazepine.Under the organic load of 0.27 g/(m~2?d),the removal rate of sulfamethoxazole can reach 95%.The highest removal rate of carbamazepine under different organic loading conditions is 53.6%,and the corresponding organic load is 0.17 g/(m~2?d).(3)The sulfamethoxazole in the experimental raw water affects the phosphorus removal process of the system by inhibiting the activity of the polyphosphate bacteria.The presence of carbamazepine inhibits the ammonia oxidation stage,thereby hindering the denitrification process,and the organic matter treatment effect of the two systems has no big difference.(4)The main removal route of sulfamethoxazole is biodegradation,and the removal of carbamazepine in water mainly depends on biodegradation and photolysis.No hydrolysis of both antibiotics occurred.For the photolysis of SMX,the neutral form has a stronger ability to absorb photons,and the photolysis increases with the increasing of temperature.The photolysis of carbamazepine only changes with temperature.The biooxidation of both antibiotics reaches the maximum at 30°C and a p H of 8.0.