title: Removal of antibiotics and antibiotic resistance genes from domestic sewage by constructed wetlands: Optimization of wetland substrates and hydraulic loading.
abstract: This study aimed to assess removal potential of antibiotics and antibiotic resistance genes (ARGs) in raw domestic wastewater by various mesocosm-scale horizontal subsurface-flow constructed wetlands (CWs) planted Cyperus alternifolius L. with different design parameters. Twelve CWs with three hydraulic loading rates (HLR 10, 20 and 30cm/day) and four substrates (oyster shell, zeolite, medical stone and ceramic) were set up in order to select the best optimized wetland. The result showed that 7 target antibiotics compounds including erythromycin-H2O, lincomycin, monensin, ofloxacin, sulfamerazine, sulfamethazine and novobiocin were detected, and all selected 18 genes (three sulfonamide resistance genes (sul1, sul2 and sul3), four tetracycline resistance genes (tetG, tetM, tetO and tetX), two macrolide resistance genes (ermB and ermC), three quinolone resistance genes (qnrB, qnrD and qnrS) and four chloramphenicol resistance genes (cmlA, fexA, fexB and floR)) and two integrase genes (int1 and int2) were positively detected in the domestic wastewaters. The aqueous removal rates of the total antibiotics ranged from17.9 to 98.5%, while those for the total ARGs varied between 50.0 and 85.8% by the mesocosm-scale CWs. After considering their aqueous removal rates in combination with their mass removals, the CW with zeolite as the substrate and HLR of 20cm/day was selected as the best choice. Combined chemical and biological analyses indicate that both microbial degradation and physical sorption processes were responsible for the fate of antibiotics and ARGs in the wetlands. The findings from this study suggest constructed wetlands could be a promising technology for the removal of emerging contaminants such as antibiotics and ARGs in domestic wastewater.
authors.affiliation: State Key Laboratory of Organic Geochemistry, CAS Research Centre for Pearl River Delta Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Organic Geochemistry, CAS Research Centre for Pearl River Delta Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Organic Geochemistry, CAS Research Centre for Pearl River Delta Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: You-Sheng
authors.initials: YS
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Organic Geochemistry, CAS Research Centre for Pearl River Delta Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China. Electronic address: guangguo.ying@gmail.com.
authors.forename: Guang-Guo
authors.initials: GG
authors.lastname: Ying
authors.affiliation: State Key Laboratory of Organic Geochemistry, CAS Research Centre for Pearl River Delta Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Shuang-Shuang
authors.initials: SS
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Organic Geochemistry, CAS Research Centre for Pearl River Delta Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Liang-Ying
authors.initials: LY
authors.lastname: He
authors.affiliation: State Key Laboratory of Organic Geochemistry, CAS Research Centre for Pearl River Delta Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Hao-Chang
authors.initials: HC
authors.lastname: Su
authors.affiliation: State Key Laboratory of Organic Geochemistry, CAS Research Centre for Pearl River Delta Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Li-Xin
authors.initials: LX
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Organic Geochemistry, CAS Research Centre for Pearl River Delta Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Fan-Rong
authors.initials: FR
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Organic Geochemistry, CAS Research Centre for Pearl River Delta Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Yong-Qiang
authors.initials: YQ
authors.lastname: Yang
mesh_terms: D000900:Anti-Bacterial Agents / Q000302:isolation & purification*; D001673:Biodegradation, Environmental; D002681:China; D024881:Drug Resistance, Bacterial; D005798:Genes, Bacterial; D012722:Sewage / Q000382:microbiology*; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000032:analysis* / Q000382:microbiology*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D053833:Wetlands
chemical_list: D000900:Anti-Bacterial Agents; D012722:Sewage; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Antibiotic resistance genes; Antibiotics; Constructed wetland; Wastewater