College of Resources, Environment and Materials, Guangxi University, Nanning, 530004, People's Republic of China.
Guangxi Bossco Environmental Protection Technology Co., Ltd, Nanning, 530007, People's Republic of China.
Environ Sci Pollut Res Int. 2023 Jul;30(34):82866-82877. doi: 10.1007/s11356-023-28201-9. Epub 2023 Jun 19.
High concentrations of arsenic and antimony contamination in soil are a potential risk to the ecological environment and human health. Soil washing can effectively and permanently reduce the soil contamination. This study used Aspergillus niger fermentation broth as a washing agent to remove As and Sb from contaminated soil. Characterization of organic acids in the fermentation broth by high-performance liquid chromatographic (HPLC) and chemically simulated leaching experiments revealed that oxalic acid played a significant role in removing As and Sb from the soil. The effect of washing conditions on the metal removal rate of Aspergillus niger fermentation broth was investigated by batch experiments, and the optimal conditions were determined: no dilution, pH 1, L/S ratio 15:1, and leaching at 25 °C for 3 h. The soils were washed three times under optimal conditions, with 73.78%, 80.84%, and 85.83% removal of arsenic and 65.11%, 76.39%, and 82.06% removal of antimony, respectively. The results of metal speciation distribution in the soil showed that the fermentation broth could effectively remove As and Sb on amorphous Fe/Al hydrous oxides in soil. The analysis of X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) of soils before and after washing showed that the washing of Aspergillus niger fermentation broth had a minor effect on the structural changes of soils. After washing, soil organic matter and soil enzyme activity were increased. Thus, Aspergillus niger fermentation broth shows excellent potential as a washing agent for removing As and Sb from soils.
土壤中高浓度的砷和锑污染对生态环境和人类健康构成潜在风险。土壤淋洗可以有效地永久性降低土壤污染。本研究使用黑曲霉发酵液作为洗涤剂，从污染土壤中去除 As 和 Sb。通过高效液相色谱 (HPLC) 和化学模拟浸出实验对发酵液中的有机酸进行了表征，结果表明草酸在去除土壤中的 As 和 Sb 方面发挥了重要作用。通过批实验研究了淋洗条件对黑曲霉发酵液去除金属的影响，确定了最佳条件：不稀释、pH 值为 1、固液比为 15:1、在 25°C 下浸出 3 h。在最佳条件下，土壤被洗涤了三次，砷的去除率分别为 73.78%、80.84%和 85.83%，锑的去除率分别为 65.11%、76.39%和 82.06%。土壤中金属形态分布的结果表明，发酵液可以有效地去除土壤中无定形 Fe/Al 水合氧化物上的 As 和 Sb。土壤淋洗前后的 X 射线衍射 (XRD) 和傅里叶变换红外光谱 (FTIR) 分析表明，黑曲霉发酵液的淋洗对土壤结构变化的影响较小。淋洗后，土壤有机质和土壤酶活性增加。因此，黑曲霉发酵液作为去除土壤中 As 和 Sb 的洗涤剂具有良好的应用潜力。
