Institute of Nuclear Agricultural Sciences, Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture and Zhejiang Province, Zhejiang University, Hangzhou, 310058, China.
Institute of Nuclear Agricultural Sciences, Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture and Zhejiang Province, Zhejiang University, Hangzhou, 310058, China.
Chemosphere. 2022 Nov;307(Pt 4):136125. doi: 10.1016/j.chemosphere.2022.136125. Epub 2022 Aug 19.
Reduced graphene oxide (RGO) is one of common carbon nanomaterials, which is widely used in various fields. Triclosan is an antimicrobial agent added in pharmaceuticals and personal care products. Extensive release of RGO and triclosan has posed potential risks to humans and the environment. The impact of RGO on the fate of triclosan in paddy soil is poorly known. C-Triclosan was employed in the present study to determine its distribution, degradation and mineralization in paddy soil mixed with RGO. Compared with the control, RGO (500 mg kg) significantly inhibited the mineralization of C-triclosan, and reduced its extractability by 6.5%. The bound residues of triclosan in RGO-contaminated soil (100 and 500 mg kg) were 2.9-13.3% greater than that of the control at 112 d. RGO also accelerated the dissipation of triclosan, and its degradation products in both treatments and controls were tentatively identified via C-labeling method and LC-Q-TOF-MS analysis. The concentrations of the major metabolites (methyl-triclosan and dechlorinated dimer) were inversely related with the concentrations of RGO. RGO at 50 mg kg or lower had a negligible effect on the degradation of triclosan in paddy soil. Triclosan was strongly adsorbed onto RGO-contaminated soil, which may play a vital role in the fate of triclosan in RGO-contaminated paddy soil. Interestingly, RGO had little effect on triclosan-degrading bacteria via soil microbial community analysis. This study helps understand the effects of RGO on the transformation of triclosan in paddy soil, which is of significance to evaluate the environmental risk of triclosan in RGO-contaminated soil.
还原氧化石墨烯（RGO）是一种常见的碳纳米材料，广泛应用于各个领域。三氯生是一种添加在药品和个人护理产品中的抗菌剂。RGO 和三氯生的大量释放对人类和环境构成了潜在风险。RGO 对稻田土壤中三氯生命运的影响知之甚少。本研究采用 C-三氯生来测定其在混合 RGO 的稻田土壤中的分布、降解和矿化。与对照相比，RGO（500mg/kg）显著抑制了 C-三氯生的矿化作用，使其提取率降低了 6.5%。RGO 污染土壤中三氯生的结合残留（100 和 500mg/kg）比对照在 112d 时分别增加了 2.9-13.3%。RGO 还加速了三氯生的消解，通过 C 标记法和 LC-Q-TOF-MS 分析，在两种处理和对照中都初步鉴定了其降解产物。主要代谢产物（甲基三氯生和脱氯二聚体）的浓度与 RGO 的浓度呈反比。RGO 浓度在 50mg/kg 或以下时，对稻田土壤中三氯生的降解影响可以忽略不计。三氯生强烈吸附在 RGO 污染的土壤上，这可能在 RGO 污染稻田土壤中三氯生的命运中起着重要作用。有趣的是，通过土壤微生物群落分析，RGO 对三氯生降解菌的影响很小。本研究有助于了解 RGO 对稻田土壤中三氯生转化的影响，这对于评估 RGO 污染土壤中三氯生的环境风险具有重要意义。
