College of Resources, Sichuan Agricultural University, Chengdu 611130, China; Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310029, China.
College of Resources, Sichuan Agricultural University, Chengdu 611130, China.
Sci Total Environ. 2019 Apr 1;659:1448-1456. doi: 10.1016/j.scitotenv.2018.12.361. Epub 2018 Dec 27.
In situ remediation and assessment of sediments contaminated with both antibiotics and heavy metals remains a technological challenge. In this study, MgCl-modified biochar (BCM) was obtained at 500 °C through slow pyrolysis of Thalia dealbata and used for remediation of sediments contaminated by sulfamethoxazole (SMX) and Cd. The BCM showed greater surface area (110.6 m g) than pristine biochar (BC, 7.1 m g). The SMX sorption data were well described by Freundlich model while Langmuir model was better for the Cd sorption data. The addition of 5.0% BCM significantly increased the sorption of SMX (by 50.8-58.6%) and Cd (by 24.2-25.6%) on sediments in both single and binary systems as compared with 5.0% BC. SMX sorption in sediments was significantly improved by addition of Cd, whereas SMX has no influence on Cd sorption on sediments. The addition of BCM distinctly decreased both SMX (by 51.4-87.2%) and Cd concentrations (by 56.2-91.3%) in overlying water, as well as in TCLP extracts (by 55.6-86.1% and 58.2-91.9% for SMX and Cd, respectively), as compared with sediments without biochar. Both germination rate and root length of pakchoi increased with increasing doses of BCM in contaminated sediments, 5.0% BCM showed greater promotion on pakchoi growth than 5.0% BC. Overall, BCM in the sediments does not only decrease the bioavailability of SMX and Cd, but it also diminishes the phytotoxicity, and thereby shows great application potential for in situ remediation of sediments polluted with antibiotics and heavy metals.
原位修复和评估同时受到抗生素和重金属污染的沉积物仍然是一项技术挑战。在这项研究中，通过缓慢热解 Thalia dealbata 获得了 500°C 的 MgCl 改性生物炭（BCM），并将其用于修复受磺胺甲恶唑（SMX）和 Cd 污染的沉积物。BCM 的比表面积（110.6 m²/g）大于原始生物炭（BC，7.1 m²/g）。SMX 的吸附数据通过 Freundlich 模型得到很好的描述，而 Langmuir 模型更适合 Cd 的吸附数据。与 5.0%BC 相比，在单一和二元体系中，添加 5.0%BCM 可显著增加沉积物对 SMX（增加 50.8-58.6%）和 Cd（增加 24.2-25.6%）的吸附。添加 Cd 可显著提高沉积物中 SMX 的吸附，而 SMX 对 Cd 在沉积物上的吸附没有影响。与不添加生物炭的沉积物相比，BCM 的添加明显降低了水体（SMX 和 Cd 的浓度分别降低了 51.4-87.2%和 56.2-91.3%）和 TCLP 提取物（SMX 和 Cd 的浓度分别降低了 55.6-86.1%和 58.2-91.9%）中的 SMX 和 Cd 浓度。与受污染的沉积物相比，添加生物炭后，白菜的发芽率和根长均增加，5.0%BCM 对白菜生长的促进作用大于 5.0%BC。总的来说，沉积物中的 BCM 不仅降低了 SMX 和 Cd 的生物可利用性，而且降低了它们的植物毒性，因此在原位修复抗生素和重金属污染的沉积物方面具有很大的应用潜力。
