Abstract:Cement-based solidification/stabilization (S/S) with DTCR (dithiocarbamate) as an additive was used to solidify and stabilize sediment containing heavy metals. The optimum ratios of cement and DTCR were determined by testing the compressive strength of the whole solidified body and leaching toxicity of granular solidified body (particle size£9.5mm). And the effect of S/S was assessed though the leaching toxicity test of granular solidified body and whole solidified body in the acidic environment (pH 3). The mechanism of S/S was analyzed by X-ray diffraction (XRD) and envrionmental scanning electron microscope (ESEM). The optimal proportion of cement and DTCR was 50% and 2% (w/w, dry basis), respectively. Under optimum conditions, the 7d compressive strength of the solidified body was up to 1.03 MPa and leaching concentrations of Cu, Zn, Pb and Cd in granular solidified body were 0.105, 4.65, 0.232, 0.123 mg/L, respectively, which could meet the requirements of the security landfill. The leaching effect in the acidic environment (pH 3) demonstrated that cement-based S/S added DTCR was better than cement-based S/S only. XRD and ESEM analysis revealed that Ca(OH)2, Hydrate Calcium Silicate (C-S-H) and Ettringite (AFt) as hydration products would be formed in hydration reaction which wrapped up heavy metals and form a solidified body with certain strength.
王川, 杨朝晖, 曾光明, 汪理科, 徐海音, 谢华明. DTCR协同水泥固化/稳定化重金属污染底泥的研究[J]. 中国环境科学, 2012, 32(11): 2060-2066.
WANG Chuan, YANG Chao-Hui, ZENG Guang-Ming, WANG Li-Ke, XU Hai-Yin, XIE Hua-Ming. Stabilization/solidification of heavy metals contaminated sediment using cement and DTCR as binder materials. CHINA ENVIRONMENTAL SCIENCECE, 2012, 32(11): 2060-2066.