Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
School of Public Health, Peking University, Beijing 100191, China.
J Hazard Mater. 2021 May 15;410:124533. doi: 10.1016/j.jhazmat.2020.124533. Epub 2020 Nov 11.
Soil washing process enhanced by surfactants is a promising technique in removing organic pollutants from soil. In this work, a simultaneous sorption and biodegradation technique was used to remove 16 PAHs from a soil washing solution (SWS) obtained by rinsing a heavily contaminated soil from a coking plant with Triton X-100 (TX-100). This was done by immobilizing a pyrene-degrading bacterial strain in polyvinyl alcohol-sodium alginate (PVA-SA) hydrogel beads. Removal performance of free bacteria, blank PVA-SA beads and beads with immobilized degrading bacteria at a low, medium and high initial concentration was evaluated. The recycling and removal performance of the used beads were also examined. Our findings showed that hydrogel beads with immobilized bacteria at a medium concentration can remove around 77% ∑16PAHs from SWS in 96 h. The beads can be recycled and reused to treat a new SWS; 32-55% ∑16PAHs was removed in 24 h. The bead provided protection for bacteria against the co-existing substances such as TX-100. The bacteria-immobilized beads are more efficient and sustainable than free bacteria and blank beads due to simultaneous sorption and biodegradation processes, thus providing a solid reference for possible industrial application of bacteria immobilization technique to deal with SWSs with complex composition.
表面活性剂强化的土壤洗脱工艺是去除土壤中有机污染物的一种很有前途的技术。在这项工作中，采用同时吸附和生物降解技术，从用 Triton X-100（TX-100）冲洗焦化厂重度污染土壤得到的土壤洗脱溶液（SWS）中去除 16 种多环芳烃。这是通过将芘降解细菌固定在聚乙烯醇-海藻酸钠（PVA-SA）水凝胶珠中来完成的。评估了游离细菌、空白 PVA-SA 珠和固定化降解细菌在低、中、高初始浓度下的去除性能。还检查了用过的珠子的回收和去除性能。我们的研究结果表明，在中等浓度下固定化细菌的水凝胶珠可以在 96 小时内从 SWS 中去除约 77%∑16PAHs。这些珠子可以回收并重复用于处理新的 SWS；在 24 小时内可去除 32-55%∑16PAHs。珠粒为细菌提供了对共存物质（如 TX-100）的保护。由于同时进行的吸附和生物降解过程，固定化细菌珠比游离细菌和空白珠粒更有效和可持续，为细菌固定化技术在处理具有复杂成分的 SWS 方面的可能工业应用提供了可靠的参考。
