The Removal Efficiency And Impact Factors Of14Antibiotics In Constructed Wetlands

Antibiotics are mainly applied in the prevention and treatment of humans and animals’diseases, and are used as a promoter in animal feeds as well. The development and proliferationof antibiotic resistence in enviromental microorganisms is a major public health concern aroundthe world. For the sake of improve the drinking water quality and prove the health of people, weneed a economical and efficient biological treatment technology to solve the problem.Cconstructed wetland (CW) has unparalleled advantages relative to the traditional sewagetreatment process in pharmaceuticals and personal care products (PPCPs) removal andinvestment, operational management, but the research about that using CW for removal ofantibiotics in domestic sewage and sewage plant effluent and the impact factors which canimpact the antibiotic removal are rare. In addition, the removal mechanism of reference and thekey design parameters are rare, too.This paper has researched the benefit and discipline of antibiotics removal and impactfactors of CW in the pilot test and field test, domestic sewage and sewage plant effluent. We hasstudied the removal of14antibiotics (sulfonamides: sulfadizine, sulfapyridine, sulfacetamide,sulfamethazine, sulfamethoxazole, trimethoprim; quinolones: norfloxacin, ciprofloxacin,lomefloxacin, ofloxacin; tetracyclines: oxytetracycline, tetracycline; macrolides: roxithromycin,erythromycin) in domestic sewage by12kinds of configuration simulation constructed wetlands(SCWs, pilot test), and determined the main factors and their significant by the orthogonal testwhich concluded that four classes antibiotics removal effect; Meanwhile, we has studied theremoval and impact factors of14antibiotics in sewage plant effluent by the vertical-horizontalsubsurface-flow complex constructed wetland and natural biological aerated filter (field test),and compared the removal of the two processes.Analyses of the conclusions of the study are as follows:(1) The removal and impact factors of antibiotics in domestic sewage by pilot testWe has studied the removal and impact factors of antibiotics in domestic sewage by12kinds of configuration simulation constructed wetland which consist of four processes (verticalsubsurface-flow CW (VFCW), upward vertical subsurface-flow CW (UVFCW), surface flowCW (SFCW), horizontal subsurface-flow CW (HFCW)), three substrates (vesuvianite, gravel, zeolite), three plants (Thalia dealbata, Arundo donax var. versicolor, unplant), three hydraulicloading rate (HLR,0.125,0.25,0.5m/d), the results shows that:Although the concentration of some antibiotics are very high,12kinds of configurationSCWs have high removal efficiencies for sulfonamides, quinolones, tetracyclines and macrolides.The process, substrate and HLR have significant effect on the removal of sulfonamides in SCW,whose shuiping have no significant difference (P>0.05), and the process, substrate, plant andHLR have no significant effect on the removal of quinolones, tetracyclines, macrolides in SCW(P <0.05), which mean these antibiotics could be removed effectively by SCW.(2) The removal and impact factors of antibiotics in domestic sewage by field testFor the sake of enhance the removal load and save the floor space, we has studied theremoval and impact factors in the vertical-horizontal subsurface-flow complex constructedwetland (CCW) which consist of VFCW and HFCW in series, and the natural biological aeratedfilter (BAF) with Bio-ceramic, blast furnace slag and gravel, to remove the antibiotics. Theremoval efficiency was compared, and the results shows that:Quinolones, tetracyclines and macrolides could be eliminated effectively by CCW and BAF,and the removal of antibiotics by planted CCW system is more effective than the unplanted BAFsystem, which mean that CWs with limited area and high HLR could remove antibiotics insewage plant effluent. The treatment of antibiotics could be affected by the HLR, and the optimalHLR for the removal of antibiotics in the CCW and BAF were1.0~1.5m/d and4.8~6.4m/d,respectively.The results about pilot test and field test also shows that, adsorption and photodegradationappears to be the most important pathways for quinolones; Tetracyclines removed by means ofadsorption processes and hydrolysis; The elimination of sulfonamides and macrolides could bethe combined action of several pathways.The above results shows that: The CW can be used to deal with the sulfonamides,quinolones, tetracyclines and macrolides in domestic sewage, and the effluent of sulfonamidesand tetracyclines can reach the level of tertiary sewage treatment process. And the CW also canbe used to deal with the quinolones, tetracyclines and macrolides in sewage plant effluent. Theremoval efficiencies of antibiotics, the impact factors, the key design parameters of CW and thepossible elimination pathways all can be used in the CW system to deal with the antibiotics treatment in the future.