含砷废物资源化产品中砷的浸出特性与环境风险分析

Leaching Characteristic and Environmental Risk Analysis of Arsenic in Resource Recovery Products Using Arsenic-Containing Waste

分别以我国某地2种含砷废物(污泥和废渣)为研究对象,用EANEN7371实验方法分析其不同资源化产品(烧制砖、免烧砖和含砷水泥等)中As的有效量浸出特性,从环境风险的角度探讨了含砷废物资源化利用的可行性.结果显示:含砷污泥进行烧砖处置后,其产品中As的有效量浸出率从15%左右升至60%～70%;含砷废渣与水泥进行混合粉磨共处置后,含砷水泥产品中As的有效量浸出率从60%～70%降至4%以下;含砷废渣制成免烧砖后,As的有效量浸出率从60%～70%降至10%左右.表明含砷污泥不宜进行烧砖处置;而含砷废渣可根据含砷量,在控制掺加比例的条件下与水泥熟料共处置生产混合水泥或作为原材料生产免烧砖.

This experiment used two types of arsenic-containing waste（sludge and residue） as raw materials to make resource recovery products（bricks,baking-free bricks and mix-cement）,investigated the availability leaching of As using the EA NEN 7371 method, and discussed their reuse feasibility from an environmental risk perspective.The results show that the availability leaching rate of As in bricks made with a mixture of arsenic-containing sludge increased from about 15% to 60%-70% ,while the availability leaching rate of As in arsenic-containing cement made with the mixture of cement and arsenic-containing residue decreased from 60%-70% to below 4% after grinding disposal.The availability leaching rate of As in baking-free bricks made with the arsenic residue reduced from 60%-70% to about 10% .Therefore,arsenic-containing sludge should not be utilized to make bricks,and the arsenic-containing residue can be co-processed in cement grinding plants or baking-free bricks manufacture under strict control of the mixing ratios.