废物水泥窑共处置产品中重金属释放潜能表征研究

通过模拟煅烧试验制取水泥熟料,并采用国标GB/T17671-1999制取混凝土样品.选用酸解法,EA NEN7371和pH静态试验分别测定了混凝土中重金属的全量、有效量和在不同pH系列中的释放量,研究了废物水泥窑共处置产品环境安全性评价中重金属的释放潜能指标.结果表明,全量和有效量存在较大差异,但二者间的相关性因元素种类不同而有较大差别,Ni,Cd的全量和有效景间相关性较好,R2分别为0.989和0.994,而Cr,As和Pb基本不存在线性相关关系;pH静态试验中最大释放量与有效量较为接近,而与全量有较大差异;有效量是废物水泥窑共处置产品使用过程中表征其重金属释放潜能的较优指标.

Characterization of the Release Potential of Heavy Metals in Cement Products from Co-processing Waste in Cement Kilns

Clinker was prepared by simulating cement calcination, which was used to produce concrete samples according to national standard GB/T17671-1999. Theacid hydrolyzation method EA NEN7371 and a pH-dependence test were used to determine the total amount, availability amount and release amount of heavy metals atdifferent pH levels, respectively; the aim was to assess the indices of the maximum release amount of heavy metals in the safety assessment of the cement product from co-processing waste in cement kilns. The results showed that there was asignificant difference between the total amount and the availability amount of heavy metals released from cement product, and their correlation varied with heavy metal species. The relationships between the total amount and availability amount of Ni and Cd are good; the correlation coefficients of R² are 0.989 and 0.994, respectively. However, there were not linear relationships between the totalamount and availability amount of Cr, As and Pb. The maximum release amount in the pH-dependence test was similar to the availability amount, but differed significantly with the total amount of heavy metals. The availability amount was themost suitable index in assessing release potential of heavy metals from the product of cement kiln co-processing in application.