Zhou Haidong, Zhao Ziming, Xu Xinxuan, Ye Mixuan, Cao Zhengcao
School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, China.
School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, China.
Waste Manag. 2022 Aug 1;150:383-393. doi: 10.1016/j.wasman.2022.07.020.
Antibiotics and antibiotic resistance genes (ARGs) in sewage sludge can cause high ecotoxicological risks in the environment and public health concerns. The aims of this study were to establish enzymatic integrated in-situ advanced anaerobic digestion (AAD) by adding cellulase and papain as well as the two enzymes combined with zero valent iron (ZVI) directly into the anaerobic digesters to explore the removal of antibiotics and ARGs under the mesophilic condition (35 °C). The methane production potential during in-situ AAD was effectively improved. Papain and cellulase at 30 mg/gTSS were most effective in improving antibiotic removal. The removal of sulfamerazine (SMZ) and sulfadiazine (SMR) could reach 89.10 % and 71.75 %. Combined enzymes with ZVI also enhanced the removal of all target antibiotics, especially roxithromycin (ROX), SMZ and SMR most significantly. Except for sul1, tetA and tetB, the removal of ARGs by papain reached 6.33 %-82.15 %. The addition of cellulase effectively improved tetA removal. The combination of biological enzymes further enhanced the removal of qnrS and ermX. The tetG, tetB, sul3, ermX, ermT, qnrS, and aac(6')-IB-CR by combined enzymes with ZVI could even not be detected after digestion. Addition of papain, cellulase, and ZVI caused variations in the dominant bacteria. All target antibiotics presented significant positive correlations with the genera norank_f__Bacteroidetes_vadinHA17, norank_f__norank_o__SJA-15, norank_f__norank_o__Aminicenantales. Redundancy analysis showed archaea Methanosaeta and Candidatus_ Methanoacidiosum genera greatly contributed to antibiotics removal with the combination of enzymes and ZVI. Co-occurrence network analysis indicated the removal of ARGs was mainly based on the changes of existence of host bacteria.
污水污泥中的抗生素和抗生素抗性基因（ARGs）会在环境中造成高生态毒理学风险，并引发公众健康担忧。本研究的目的是通过添加纤维素酶和木瓜蛋白酶以及将这两种酶与零价铁（ZVI）直接添加到厌氧消化池中，建立酶促原位高级厌氧消化（AAD），以探索中温条件（35℃）下抗生素和ARGs的去除情况。原位AAD过程中的甲烷生产潜力得到了有效提高。30mg/gTSS的木瓜蛋白酶和纤维素酶在提高抗生素去除率方面最为有效。磺胺甲恶唑（SMZ）和磺胺嘧啶（SMR）的去除率分别可达89.10%和71.75%。酶与ZVI的组合也提高了所有目标抗生素的去除率，尤其是对罗红霉素（ROX）、SMZ和SMR的去除效果最为显著。除sul1、tetA和tetB外，木瓜蛋白酶对ARGs的去除率达到6.33%-82.15%。纤维素酶的添加有效提高了tetA的去除率。生物酶的组合进一步提高了qnrS和ermX的去除率。酶与ZVI组合消化后甚至检测不到tetG、tetB、sul3、ermX、ermT、qnrS和aac(6')-IB-CR。木瓜蛋白酶、纤维素酶和ZVI的添加导致了优势细菌的变化。所有目标抗生素与norank_f__Bacteroidetes_vadinHA17属、norank_f__norank_o__SJA-15属、norank_f__norank_o__Aminicenantales属呈显著正相关。冗余分析表明，甲烷八叠球菌属和候选甲烷酸菌属在酶与ZVI组合的情况下对抗生素去除有很大贡献。共现网络分析表明ARGs的去除主要基于宿主细菌存在情况的变化。
