溶解态硅酸盐对臭葱石稳定性影响  

Effect of dissolved silicate on the stability of scorodite

作　　者：马旭 王少锋[1] 郑阳 段伊行 王新[1] 贾永锋[1] 

机构地区：[1]中国科学院沈阳应用生态研究所污染生态与环境工程重点实验室,沈阳110016 [2]中国科学院大学,北京100049

出　　处：《生态学杂志》2018年第1期237-244,共8页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(41530643和41473111)资助

摘　　要：溶解态硅酸盐在矿物表面的吸附和聚合行为影响矿物在水环境中的稳定性。研究溶解态硅酸盐在矿物表面的聚合行为及其对矿物稳定性的影响具有重要的理论和实际意义。本文研究了溶解态硅酸盐在臭葱石上的吸附动力学,利用衰减全反射红外光谱(ATR-FTIR)表征其吸附行为,并对吸附硅的臭葱石进行了淋溶稳定性分析。结果表明:溶解态硅酸盐与臭葱石在弱酸性环境中同时受吸附机理与受置换反应的控制;在pH3和pH4时,臭葱石吸附硅量较高,红外光谱显示硅在臭葱石表面形成类似于硅酸(SiO_2·xH_2O)的高聚物;此外,含硅臭葱石与臭葱石相比,在pH 4、pH 6和pH 8的淋溶稳定性实验中砷浸出量分别降低了68.1%、52.5%和15.5%。本研究可为有色冶炼含砷废渣的储存及进一步稳定化降低其环境风险提供科学依据。The adsorption and polymerization of dissolved silicate on minerals affect its stability in the aquatic environment. The study of silicate chemistry on mineral surfaces is theoretically and practically important to understand the polymerization behavior and effect on its stability. In this work, the adsorption kinetics of dissolved silicates on scorodite was investigated, their polymerization behavior was characterized by attenuated total reflectance Fourier transform infrared spectroscopy （ATR-FTIR）, and the stability of the silicate adsorbed scorodite was analyzed. The results showed that the adsorption of silicates by scorodite could be attributed to chemical adsorption and replacement reaction. Higher amount of silicate absorbed by scorodite at pH 3 and 4 and the ATRFTIR results also indicated that the adsorbed polymeric silicates on scorodite surface showed a structure similar to silicic acid （SiO2·xH2O）. In addition, the leaching stability test showed that the amount of arsenic leached out from silicate absorbed scorodite was decreased by 68.1%, 52.5% and 15.5% at pH 4, 6 and 8 respectively, compared with that from scorodite. The findings in this work may have important implications for further stabilizing and reserving the arsenic containing residue from the metallurgical industry to reduce their environmental risk.

关 键 词：硅酸盐 臭葱石 聚合 稳定性 

分 类 号：X703[环境科学与工程—环境工程]