污泥制备水泥及其重金属释出的初步研究

城市污泥的最佳出路是无害化处理，资源化利用，产业化发展，将城市污泥作为生态水泥的生产配料是目前污泥资源化利用的新途径。该文将城市污泥作为配料分别按照6％和20％的比例与粘土混合制成水泥并养护7天后，测定水泥熟料的一些物理化学性质以及水泥固结体的重金属浸出含量。研究结果表明：与粘土相比，污泥有烧失量大、杂质含量高、A1203含量偏低的特点；以低比例污泥制备成的水泥熟料的化学成分、矿物组成和物理性能更接近于普通水泥熟料；水泥固结体中铅、镉、总铬、铜和锌可浸出含量未超出GB5085．3—1996浸出毒性标准，表明污泥中的重金属离子得到有效的束缚。

A Preliminary Study on Production of Eco - cement Using Sludge and Its Risk of Heavy Metals Release

The best disposal method of municipal sewage sludge was nonhazardous resource reuse and industrialization.Therefore,municipal sewage sludge was reused as burden of cement.In this paper,eco-cement was produced using sewage sludge at the ratios of 6% and 20%,mixed with clay and limestone.After 7-day maintenance of cement clinker,some properties of cement clinker and concentrations of heavy metals in the condensates leachate were determined.The result showed that chemical and mineral composition and physical property of eco-cement burdened with low content of sewage sludge were closer to that of common cement,compared with the eco-cement burdened with high content of sewage sludge.The result also showed that concentrations of heavy metals(including Pb,Cd,Cr,Cu,and Zn) in the condensates leachate were less than China national identification standards for hazardous wastes(GB5085.3-1996),indicating that heavy metals were stabilized and solidified in the eco-cement.