title: Comparison of ozone and thermal hydrolysis combined with anaerobic digestion for municipal and pharmaceutical waste sludge with tetracycline resistance genes.
abstract: Biosolids from wastewater treatment plant (WWTP) are environmental reservoirs of antibiotic resistance genes, which attract great concerns on their efficient treatments. Anaerobic digestion (AD) is widely used for sewage sludge treatment but its effectiveness is limited due to the slow hydrolysis. Ozone and thermal hydrolysis pre-treatment were employed to improve AD efficiency and reduce antibiotic-resistant genes in municipal and pharmaceutical waste sludge (MWS and PWS, respectively) in this study. Sludge solubilization achieved 15.75-25.09% and 14.85-33.92% after ozone and thermal hydrolysis, respectively. Both pre-treatments improved cumulative methane production and the enhancements were greater on PWS than MWS. Five tetracycline-resistant genes (tet(A), tet(G), tet(Q), tet(W), tet(X)) and one mobile element (intI1) were qPCR to assess pre-treatments. AD of pre-treated sludge reduced more tet genes than raw sludge for both ozonation and thermal hydrolysis in PWS and MWS. Thermal hydrolysis pre-treatment was more efficient than ozone for reduction after AD. Results of this study help support management options for reducing the spread of antibiotic resistance from biosolids.
authors.affiliation: Department of Municipal and Environmental Engineering, Beijing Jiaotong University, Beijing 100044, People's Republic of China.
authors.forename: Jin
authors.initials: J
authors.lastname: Pei
authors.affiliation: Department of Municipal and Environmental Engineering, Beijing Jiaotong University, Beijing 100044, People's Republic of China. Electronic address: yaohongts@163.com.
authors.forename: Hong
authors.initials: H
authors.lastname: Yao
authors.affiliation: Department of Municipal and Environmental Engineering, Beijing Jiaotong University, Beijing 100044, People's Republic of China.
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Municipal and Environmental Engineering, Beijing Jiaotong University, Beijing 100044, People's Republic of China.
authors.forename: Jia
authors.initials: J
authors.lastname: Ren
authors.affiliation: Department of Municipal and Environmental Engineering, Beijing Jiaotong University, Beijing 100044, People's Republic of China.
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Yu
mesh_terms: D005798:Genes, Bacterial; D006868:Hydrolysis; D010126:Ozone; D012722:Sewage; D013753:Tetracycline Resistance / Q000235:genetics*; D014865:Waste Disposal, Fluid
chemical_list: D012722:Sewage; D010126:Ozone
keywords: Anaerobic digestion; Municipal sludge; Ozone; Pharmaceutical sludge; Tetracycline resistance genes; Thermal hydrolysis