污泥生物炭增强对环丙沙星的去除：腐殖酸的影响。
Enhanced ciprofloxacin removal by sludge-derived biochar: Effect of humic acid.
机构信息
Department of Biological and Environmental Engineering, Changsha University, Changsha, 410003, PR China.
College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China.
出版信息
Chemosphere. 2019 Sep;231:495-501. doi: 10.1016/j.chemosphere.2019.05.151. Epub 2019 May 23.
Humic acid (HA) is ubiquitous in the environment, and its effect on the adsorption of pollutants onto biochar (BC) has been widely investigated. However, the catalytic degradation of organic contaminants induced by persistent free radicals (PFRs) in BC is not negligible. In this study, two different source of external HA, dissolved HA and coated HA, was employed to assess the effect of HA on the degradation of organic contaminant ciprofloxacin (CIP) by PFRs in BC. Results showed that relatively low concentration of dissolved HA promoted the removal of CIP from 59.78% (control) to 66.70% (5 mg/L dissolved HA) by BC, but higher concentration of dissolved HA inhibited. By contrast, coated HA altered the characteristics of BC and had negative impact on organics removal. The removal of CIP by BC in the presence of HA did not have a great difference at pH 6-9, and increasing dissolved oxygen promoted CIP degradation. In addition, the contribution of CIP removal led by adsorption was 47.61%, 41.62% and 47.84% respectively for BC, BC + dissolved HA and 1% HA coated BC. Correspondingly, the contribution of CIP removal led by •OH induced from PFRs in BC was respectively 21.88%, 35.58% and 25.11%, and the contribution led by PFRs themselves oxidation was 30.51%, 22.80% and 27.05%, respectively. The calculated contributions of adsorption and degradation to CIP removal demonstrated that the contribution of degradation to CIP removal led by •OH increased, while the contribution led by PFRs themselves oxidation was inhibited in the presence of dissolved and coated HA.
腐殖酸（HA）在环境中无处不在，其对污染物在生物炭（BC）上吸附的影响已得到广泛研究。然而，BC 中持久性自由基（PFRs）诱导的有机污染物催化降解作用也不可忽视。在本研究中，采用了两种不同来源的外源性 HA（溶解态 HA 和包裹态 HA）来评估 HA 对 PFRs 在 BC 中降解有机污染物环丙沙星（CIP）的影响。结果表明，相对低浓度的溶解态 HA 可将 CIP 的去除率从 59.78%（对照）提高到 66.70%（5mg/L 溶解态 HA），但较高浓度的溶解态 HA 则会抑制其去除率。相比之下，包裹态 HA 改变了 BC 的特性，对有机物的去除产生了负面影响。在 pH 值为 6-9 时，HA 的存在对 BC 去除 CIP 的影响差异不大，而增加溶解氧则可促进 CIP 的降解。此外，在 BC、BC+溶解态 HA 和 1%HA 包裹的 BC 中，由吸附作用导致的 CIP 去除贡献分别为 47.61%、41.62%和 47.84%。相应地，由 PFRs 引发的 •OH 导致的 CIP 去除贡献分别为 21.88%、35.58%和 25.11%，而由 PFRs 自身氧化导致的 CIP 去除贡献分别为 30.51%、22.80%和 27.05%。由吸附和降解作用对 CIP 去除的贡献计算结果表明，在溶解态和包裹态 HA 存在的情况下，由 •OH 引起的降解作用对 CIP 去除的贡献增加，而由 PFRs 自身氧化引起的贡献则受到抑制。
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