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以污泥为基料制备的生态混凝土为对象,研究了去离子水、硫酸-硝酸溶液和醋酸溶液三种浸取剂在浸取混凝土过程中重金属的浸出情况和液相p H值变化特性。结果表明,重金属铅(Pb)、铬(Cr)、镉(Cd)、铜(Cu)和锌(Zn)的浸出量随着混凝土粒径的减小而逐渐增加,砷(As)的浸出量随着混凝土粒径的减小略有减小;液相p H值随着时间的增加而增加,浸取剂为醋酸溶液时,平衡后液相p H值最小;浸取剂的种类对混凝土中重金属浸出结果影响很大,3种浸取剂条件下重金属的浸出率大小为:醋酸溶液>硫酸-硝酸溶液>去离子水,但重金属的浸出浓度都远低于GB 5085.3—2007《危险废物鉴别标准浸出毒性鉴别》规定的限值,重金属固化效果很好。
Taking the ecological concrete prepared from sludge as the base material, the leaching conditions of heavy metals and the change of p H value in the liquid phase of the three kinds of leaching agents of deionized water, sulfuric acid-nitric acid solution and acetic acid solution were studied. The results showed that the leaching amount of lead, chromium, cadmium, copper and zinc increased with the decreasing of the particle size of concrete. The leaching amount of arsenic (As) With the decrease of particle size, the p H value of liquid phase increased with the increase of time. When the leaching agent was acetic acid solution, The leaching rate of heavy metals is greatly affected. The leaching rates of heavy metals under the three leaching conditions are as follows: acetic acid solution> sulfuric acid-nitric acid solution> deionized water, but the leaching concentrations of heavy metals are much lower than those of GB 5085.3-2007 “hazardous waste Identification of standard leaching toxicity, ”the provisions of the limit, heavy metal curing effect is very good.