Stabilization/Solidification (S/S) can be regarded as necessary for remediation of heavy metal contaminated soil. There is, however, solid agent is not very convenient to use. Water-soluble thiourea-formaldehyde (WTF) is a novel chelating agent, which has more practical applications. The process of WTF resin for S/S process of heavy metal contaminated soils was studied.

Laboratory-prepared slurries, made of field soils spiked with Cd²⁺ and Cr⁶⁺ were treated with WTF resin. The toxicity characteristic leaching procedure (TCLP) showed that with 2 wt% WTF, in the neutral condition of soil after treatment for 7 days, the leaching concentrations of Cd²⁺ and Cr⁶⁺ in contaminated soil were decreased by 80.3% and 92.6% respectively. Moreover, Tessier sequence extraction procedure showed WTF resin reduced the leaching concentration by transforming heavy metal from exchange form to organic form. The structure of WTF is obtained according to elemental analysis result and reaction mechanism. Through analysis of the infrared spectrogram of WTF and WTF heavy mental chelating precipitation, WTF can form stable chelate with heavy mental through coordination. The significant groups are hydroxyl, nitrogen and sulphur function groups in WTF mainly. Toxicology test revealed that the WTF resin is nontoxic to microorganism in the soils.

稳定/增固（S / S）被认为是修复重金属污染土壤的必要条件。但是，固体剂的使用不是很方便。水溶性硫脲甲醛（WTF）是一种新型的螯合剂，具有更实际的应用。研究了用于重金属污染土壤S / S工艺的WTF树脂工艺。

用WTF树脂处理由掺有Cd ²⁺和Cr ⁶⁺的田间土壤制成的实验室制浆。毒性特征浸出法（TCLP）表明，在WTF为2 wt％的条件下，土壤中性处理7天后，Cd ²⁺和Cr ⁶⁺的浸出浓度较高。污染土壤中的污染物分别减少了80.3％和92.6％。此外，Tessier序列提取方法表明WTF树脂通过将重金属从交换形式转化为有机形式而降低了浸出浓度。根据元素分析结果和反应机理，获得了WTF的结构。通过分析WTF和WTF重金属螯合沉淀的红外光谱图，WTF可以通过协调形成重金属螯合的稳定螯合物。在WTF中，主要的基团主要是羟基，氮和硫官能团。毒理学测试表明，WTF树脂对土壤中的微生物无毒。