| Environmental pollution and eco-toxicological effects of antibiotics has become one of the majorenvironmental problems in China and even in the whole world. With the rapid development and applicationof environmental detection and analysis measures, the residual, hazards and removal of micro pollutantssuch as antibiotics in the drainage systems has gradually caused wide concern among the public, especiallythe environmentalist.Recycling of urban sewage is one way of effective solutions to the current growing water scarcity. Theurban sewage treatment plant has become one of the main sources of antibiotic drugs into the environment.Because most of the existing traditional wastewater treatment process of removing antibiotics is not soeffective and the mechanism of removal is controversial, antibiotics discharged into the water have becomea great challenge to the municipal wastewater recycling. So it has become a serious problem to discuss andresearch a reliable, efficient and economically feasible treatment process aimed at removing the antibioticon the basis of higher efficiency of the existing sewage treatment plant to remove the common pollutants.In order to improve the removal of sulfonamides in the existing wastewater treatment system,thispaper,based on investigating the concentration distribution of sulfadiazine(SD) and sulfamethoxazole(SMX)in each section of two sewage treatment plants in Tai’an City, took traditional treatment process SBR andtwo types of typical advanced treatment process to optimize the SD and SMX in artificial wastewater,studied systematically the influencing factors of treatment process and optimum parameters, and finally putforward a process of improving the removal of antibiotics in the existing wastewater treatment plants. Themain contents are as follows:（1）Analyzed the pollution characteristics of SD and SMX in two sewage treatment plants of Tai’anCity by solid-phase extraction and high performance liquid chromatography (HPLC). The results showedthat influent concentration varies from different sources of sewage: The influent concentration of SD andSMX were165.8ng L-1and324.3ng L-1in Plant A for domestic sewage and the influent concentrationswere88.9and165.3ng L-1in Plant B for industrial wastewater; that removal rates varied from differentprocesses: the removal rates of SD and SMX in Plant A and B were48.3%、44.9%and39.1%、35.8%respectively; that the removal rates varied from different sections in Plant A, and the highest removalefficiency took place in aerobic cells, in which removal rates of SD and SMX were29.0%and20.6%%;that the removal mechanisms of SD and SMX were mainly adsorbed into particulate matter and theconcentrations of SD and SMX in concentrated sludge were135.4and285.3ng g-1.（2） Optimized the parameters of removing two sulfa antibiotics in the SBR wastewater process byextending the sludge reaction time (SRT) and hydraulic reaction time (HRT). Experimental results showedthat extending the total HRT, improving the proportion of aerobic period-anaerobic period and extending the SRT contributed to the removal rates of SD and SMX: when the total HRT was480min, the SRT was25d, and the aerobic to anaerobic ratio was0.83, the removal rates of SD and SMX maintained at48~56%,51~58%;(3) Strengthened the efficiency of the removal of two antibiotics in the sewage system by usingFenton reagent method, ferrate method and adsorption method. Experimental results showed that when thedischarge of sewage was0.4L and the concentration of SD and SMX was1.0mg·L-1, for the method offerrate, the optimum dosage was0.15mmoL L-1, pH was from6to7, the temperature was25℃, and thebest reaction time was10min, when the removal rates of SD and SMX reached88.6%and88.9%; for theFenton reagent method，the removal rate increased with the oxidant and catalyst dosage increased, theoptimum dosage was Fe2+=0.015mmoL L-1, H12O2=0.2mmoL L-, the initial reaction pH was4, thetemperature was25℃, the best reaction time was60min, the removal rates of SD and SMX reached92%and over99%; for the microporous resin adsorption method, the optimal dosage was1.6g, pH was from6to7, the equilibrium time was120min, absorption temperature was20℃, the removal rates of SD andSMX were80.8%and88.2%，and the removals of SD and SMX’s were in line with the first order kineticsmodel; when using activated carbon to remove SD and SMX, the optimum dosage was100mg, pH wasfrom6to7, the equilibrium time was180min., the removal rates of SD and SMX reached79.7%and91.5%and the removals of SD and SMX’s were in line with the first order kinetics model.Meanwhile，the experimental results showed that optimized SBR technology could maintain theoriginal removal efficiency for the conventional indicators such as COD; that the advanced treatment is notso effective for the conventional indicators, and the removal rate was only about10%~35%; in sewagesystems of conventional biological treatment，increasing the depth treatment could effectively removeconventional pollutants and trace contaminants in sewage. |
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