混凝法去除城市生活污水中抗性基因

采用聚合氯化铝(PACl)和聚合硫酸铁(PFS)混凝处理城市生活污水(格栅出水和二级出水),考察混凝剂投加量、pH值对污水中抗生素抗性基因(ARGs)的去除率影响。结果表明,随着PACl和PFS投加量的增加,污水中目标基因的去除率先升高后降低;在pH 3~10的范围内,PACl对目标基因的去除效果随pH值的增加而降低,PFS对目标基因的去除随着pH值的增加先升高后降低。对于格栅出水,PACl和PFS的最佳投加量为400 mg/L,基因的去除率分别达到2.33~2.97 log和0.98~2.11 log,对于二级出水,PACl和PFS的最佳投加量分别为200 mg/L和150 mg/L,基因的去除率分别为1.85~2.64 log、1.81~2.46 log;混凝去除最优pH条件分别为pH=3(投加PACl)及pH=5~6(投加PFS)。PACl的处理效果优于PFS。

Removal of antibiotic resistant genes in municipal wastewater with coagulation method

Municipal wastewater (both screened water and secondary effluent) was treated with poly aluminum chloride (PACl) and ploy ferric sulfate (PFS) to remove antibiotic resistance genes (ARGs) respectively. The optimal dosages of coagulants and pH value were investigated. The results indicated that the removal of target genes first increased and then decreased with increasing coagulant dosage. When increasing pH value from 3 to 10, the removal of ARGs decreased for PACl coagulation, but first increased and then decreased for PFS coagulation. The maximum removal for ARGs for the screened water were achieved when adding 400 mg/L coagulants with the removal of 2.33~2.97 log and 0.98~2.11 log by PACl and PFS, respectively. For secondary effluent, the optimal dosages were 200 mg/L for PACl and 150 mg/L for PFS, with the removal of ARGs of 1.85~2.64 log and 1.81~2.46 log, respectively. The optimization pH for removing ARGs were 3 for PACl and 5~6 for PFS, respectively. PACl could achieve better removal of genes than PFS.