The Behavior Of Typical Tetracycline In Discharge Of Tail Water

Water shortage is an important question in our country,while the problem of groundwater which is used as a vital source of fresh water has become more and more serious.In recent years,pollution of trace compounds has exacerbated groundwater problems.Tetracycline antibiotics(TCs),which is a kind of trace organic pollutants,has caused greater harm to the groundwater due to their unreasonable use and emissions.Its existence and removal in the groundwater cause the attention of people gradually.In order to prevent groundwater pollution,it is necessary to study the transformation of TCs.For the sake of testing trace pollutants in environmental medium,a set of testing method which meet the precision requirement is needed first.So the research established a whole set of methods,which can be used to separate and detect the TCs.Based on agilent UPLC/MS/MS liquid-triple-quad system,the research selected the appropriate mobile phase and elution procedure,Through the optimized method,the detection limit meet the requirements of precision testing in the water environment.Experimental field was sited in Changzhou Chengbei wastewater treatment plant.In order to assess the influence of tail water discharged into surface water and groundwater,dig wells to sample at intervals on the west side of river bank.The sampling wells were located in the treatment plant and Hanjiang Road.Collect the tail water,surface water and groundwater.Then detect the TCs in them.The results show that the TCs detected in the tail water are more than that in the river and groundwater.Make ecological risk assessment of the four TCs,while the risk levels of tetracycline(TC)and doxycycline(OTC)were at medium risk.Therefore,we choose TC and OTC as the target pollutants and carry out the research.To study the transfer laws of TC and OTC,the adsorption and desorption in soil medium were carried out in the laboratory.The soil was collected in river sediments and aeration zone.By adsorption thermodynamics and kinetics experiment,determine the adsorption equilibrium time and equilibrium adsorption quantity of the TCs in soil respectively.Meanwhile,the adsorption effects of TCs in the soil were better than that in the aeration zone.By desorption,it is determined that the TCs has hysteresis in the soil and the delay coefficient is obtained.Carry out biodegradation experiment of TCs in the soiland use the first order kinetics equation to fit.Degradation effects of the sterilization are significantly better than sterilized soil.The soil column simulation experiment was constructed,and the infiltration rate of the soil column was decreased continuously,and the stability was finally maintained.Through static and dynamic experiments for parameters,construction of antibiotics in soil column migration equation of one dimension,found SMZ and TMP in prediction of soil column 1 through time need 69 d and 1858 d,respectively,in the actual injection 15 d concentrations of SMZ and TMP was detected.SMZ and TMP in prediction of soil column 2 through time 0.95 d and 15.3 d,respectively,in the actual detection of SMZ penetration time earlier than theory,for 5 h,failed to detect the concentration of TMP in injection period.By obtaining the parameters through absorption and degradation experiments,construct the equation of migration and transformation of antibiotics in soil column.The equation can better fit the migration process of TC and OTC in soil...