The ability of thiol-modified humic acids (HAs) to release arsenic in tailings soil after being modified with different sulfur-containing reagents were significantly improved. The structure and physicochemical properties of humic acid (HA) before and after thiol-modification were characterized. The 3-MPTS-HA treated with 3-mercaptopropyltrimethoxysilane (3-MPTS) effectively improved the mobility of arsenic, and its reducing ability was increased from 2 mmol g⁻¹ to 3.54 mmol g⁻¹. The S content of humic acids were also significantly increased after treatment with sulfur-containing reagents, in which the oxygen-containing functional group (e.g., C = O, C–O) on the surface of HA may be the active sites for binding with sulfur-containing reagents. It was found in the XPS spectrum that because the thiol group is easily oxidized, there are many S forms in thiol-modified HA. The –SH content in Na₂S·9H₂O-HA, l (+)-Cysteine-HA (Cys-HA), thioglycolic acid (TGA-HA) and 3-MPTS-HA was determined by fluorescence method to be 13.9, 78.45, 90.34, and 192.29 μmol g⁻¹, respectively. The study demonstrated that surface thiol modification can increase the abundance of thiol in HA and enhance reactivity, which will further promote the application of HA in the treatment of heavy metal contaminated tailing soil.

硫醇修饰的腐殖酸（HAs）在用不同的含硫试剂修饰后在尾矿土壤中释放砷的能力得到了显着提高。表征了硫醇修饰前后腐殖酸（HA）的结构和理化性质。3-巯基丙基三甲氧基硅烷（3-MPTS）处理的3-MPTS-HA有效提高了砷的迁移率，其还原能力从2 mmol g ^-1增加到3.54 mmol g ^-1。用含硫试剂处理后，腐殖酸的S含量也显着增加，其中HA表面上的含氧官能团（例如C = O，C–O）可能是与含硫试剂。在XPS光谱中发现，由于硫醇基很容易被氧化，因此在硫醇修饰的HA中存在许多S形式。通过荧光法测定Na ₂ S·9H ₂ O-HA，l（+）-半胱氨酸-HA（Cys-HA），巯基乙酸（TGA-HA）和3-MPTS-HA中的–SH含量为13.9 ，78.45、90.34和192.29μmolg ^-1， 分别。研究表明，表面硫醇修饰可以增加HA中硫醇的含量并增强反应性，这将进一步促进HA在重金属污染尾矿土壤处理中的应用。