塔宾曲霉协同磷酸盐钝化土壤有效态重金属

Passivation of Soil Available Heavy Metal by Phosphate and EPS Excreted from Aspergillus Tubingensis

钝化是土壤重金属修复策略之一,而磷酸盐是一种常用的钝化剂。通过液相沉淀实验发现塔宾曲霉F12胞外聚合物(EPS)具有协同磷酸盐钝化有效态重金属的作用,可以作为复合钝化剂使用。随后利用响应面法分析了在多金属土壤体系下复合钝化剂的钝化能力。结果表明,EPS的加入能明显提高KH_2PO_4的沉淀量。EPS协同KH2PO4钝化有效态镉、铜、镍、铅和锌的钝化率分别为65.7%,42.4%,49.9%,80.7%和39.0%。认为该方法具有实际应用前景。

Passivation is one of the remediation strategies for heavy metals in soil, and phosphate is a commonly used passivating agent. Through the liquid phase precipitation experiment, it was found that the extracellular polymer substance（EPS） of aspergillus tubingensis F12 could be used as a compound passivating agent with the synergism of phosphate passivation on the available heavy metals. Subsequently, the passivation ability of the compound passivating agent in the polymetallic soil system was analyzed by response surface methodology. The results show that the addition of EPS can significantly increase the precipitation of potassium dihydrogen phosphate. The passivation rates of available cadmium, copper, nickel, lead and zinc were 65.7%, 42.4%, 49.9%, 80.7% and 39%, respectively, with EPS synergistic with potassium dihydrogen phosphate passivation. It is considered that the method has a practical application prospect.