The Distribution Of New Pollutants In Drinking Water And Water Supply In Suzhou

In this paper,on the basis of reviewing the preparation technique and Instrumental analytical methods of the trace of antibiotic residues in the source of drinking water,a efficient,accurate method for determination of antibiotic residues in the source of drinking water was developed by solid-phase extraction followed by High Performance Liquid/Triple Quadrupole.The established methods were successfully applied to analysis water quality of Taihu Basin and the main water supply plant in Suzhou.As a result,the space and seasonal distribution law of antibiotics in Taihu Basin and water supply plant were studied.Beyond that,the removal efficiency of the trace antibiotic residues in the water plant craft was also discussed.This dissertation include the following contents and conclusions:(1)Study on analysis method of the trace antibiotic residues by SPE-HPLC/MS~2in the source of drinking water.9 antibiotics,sulfadiazine,sulfamethoxazole,norfloxacin,enrofloxacin,oxytetracycline,cefotaxime sodium,roxithromycin,were chosen as the target compounds to study their instrument analysis method and pretreatment method in water.By optimizing the solid phase extraction methods,the conditions of the final optimized instrument were as follows:Oasis HLB(500mg,6cc)extraction cartridge was found to possess the best extraction efficiency for antibiotic residues in water.Water sample pH was adjusted to 4.The samples were loaded onto the cartridge at a flow rate of 10mL/min.After that,the cartridges were rinsed with 9mL methanol to a 10mL centrifugal tube with cork.The HPLC/MS~2 was operated on the multi reaction monitoring(MRM)mode to analyze the target antibiotics.0.1%(v:v)formic acid and acetonitrile were used as the inorganic(A)and the organic(B)mobile phases,respectively.Using this method,the calibration curves of the seven antibiotic residues were linear in the range of 0.5~200ng/L,and the detection limits were in range of 0.1~1.2 ng/L,the average recovery rates of them in samples were in range of 68%~112%,the RSD were in range of 1.6%~10.7%.(2)The analysis methods for determing the trace antibiotic residues in the source of drinking water were applied to study on the distribution variation in Taihu basin.A total of 9 sampling sites were selected for the analysis of the target antibiotics in Taihu basin by means of the optimized instrumental analysis method and sample pretreatment method.The results showed that higher detectable concentration of antibiotics were detected in the east and north of Taihu basin which was in contrast to the lowest concentration in the middle of lake.The results may have to do with effluent discharge and spatial location of aquaculture.Besides,there was obviously seasonal variation of the trace antibiotics concentration in Taihu basin:Higher concentration of antibiotics were detected in winter and spring because of the two seasons are periods of high incidence of diseases such as influenza.Summer and autumn(the sampling time of this experiment was July and October respectively)were the peak periods of aquaculture in Taihu lake,therefore,detectable concentration of antibiotics were increased along with increase of consumption of antibiotics,especially animal-derived antibiotics increased significantly in sites where aquaculture was concentrated.(3)The analysis methods for determing the trace antibiotic residues in the source of drinking water were applied to study on the distribution variation in water supply plant.With the exception of cefotaxime sodium,the other six antibiotics were all detected,of which sulfamethoxazole had the largest detection concentration.The total concentration of antibiotics in source water were 14.04~42.27ng/L,in finished water were 3.48~9.82ng/L,in water pipe network peripheral were 2.07~8.3ng/L.Different water treatment processes had different removal efficiency of target antibiotics.For example,the total absolute removal rate of ozonation pool was 59.3%,but activated carbon filter just only 11.8%.Sedimentation tanks and sand filters were little to reduce the concentration of antibiotics.The seasonal distribution pattern of antibiotic pollution was similar to that of Taihu basin:starting from April,with the increase of rainfall in the Taihu basin,the concentration of various antibiotics in the water was diluted and gradually decreased until the water level in the Taihu reached the highest in July and the concentration of antibiotics dropped to the minimum.Then in January which was the high incidence period of various influenza and other diseases.The residual concentration of antibiotics in water increased with demand increasing for various antibiotics.