College of Environment and Climate, Guangdong Provincial Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, 511443, People's Republic of China.
College of Environment and Climate, Guangdong Provincial Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, 511443, People's Republic of China.
Chemosphere. 2024 Sep;364:143165. doi: 10.1016/j.chemosphere.2024.143165. Epub 2024 Aug 23.
Antimony (Sb) pollution in surface water and soil has earned extensive attention. Our previous study synthesized a new class of alumina supported Fe-Mn binary oxide (Fe-Mn@AlO) and found that MnO in the composite oxidized Sb(III) to Sb(V) and FeOOH and AlO played an indispensable role in adsorption of Sb(III) and Sb(V). This study further explored the removal of Sb in surface water and in situ sequestration of Sb in Sb-contaminated field soil via Fe-Mn@AlO. Sb removal from water was pH independent and the removal efficiencies of Sb(III) and total Sb kept constant at 95.4% and 60.5%, respectively, over a pH range of 5.0-10.0. Increasing dissolved organic matter (DOM) from 0 to 22.8 mg/L had negligible effect on Sb(III) removal whereas inhibited the total Sb removal from 60.5% to 51.2%. Dissolved oxygen cannot oxidize aqueous Sb(III), yet, enhanced the Sb(III) removal whereas decreased the total Sb removal. The composite performed well in natural surface water with high DOM and inorganic ligands. In addition, the composite effectively immobilized Sb in field soil. 5% of the composite significantly inhibited the HSO and HNO leachable Sb by 93.6% after 30 d. The amendment transformed the Sb speciation from more easily available fractions (i.e., exchangeable, carbonate-bound, and Fe-Mn oxides-bound species) into more stable fractions (i.e., organic material bound and residual species), leading to declined Sb bioaccessibility and reduced environmental risk. The composite facilitated a long-term stability of Sb in soil. The study demonstrated an easy, fast, and effective strategy for efficient immobilization of Sb in water and soil.
水中和土壤中的锑污染受到了广泛关注。我们之前的研究合成了一种新型氧化铝负载的 Fe-Mn 二元氧化物（Fe-Mn@AlO），发现复合材料中的 MnO 将 Sb(III)氧化为 Sb(V)，FeOOH 和 AlO 在吸附 Sb(III)和 Sb(V)方面发挥了不可或缺的作用。本研究进一步通过 Fe-Mn@AlO 去除地表水中的 Sb 和原位固定 Sb 污染农田土壤中的 Sb。水中 Sb 的去除与 pH 无关，在 pH 为 5.0-10.0 范围内，Sb(III)和总 Sb 的去除效率分别保持在 95.4%和 60.5%不变。溶解有机物（DOM）从 0 增加到 22.8mg/L 对 Sb(III)的去除几乎没有影响，但将总 Sb 的去除率从 60.5%抑制到 51.2%。溶解氧不能氧化水中的 Sb(III)，但能增强 Sb(III)的去除，同时降低总 Sb 的去除。该复合材料在高 DOM 和无机配体的天然地表水中表现良好。此外，该复合材料有效地固定了农田土壤中的 Sb。在 30 天后，5%的复合材料可使 HSO 和 HNO 可浸出 Sb 的含量分别减少 93.6%。该改良剂将 Sb 的形态从更易利用的形态（如可交换态、碳酸盐结合态和 Fe-Mn 氧化物结合态）转化为更稳定的形态（如有机物质结合态和残余态），降低了 Sb 的生物可利用性，降低了环境风险。该复合材料提高了 Sb 在土壤中的长期稳定性。该研究为水中和土壤中 Sb 的有效固定提供了一种简便、快速和有效的策略。
