含重金属危险固体废物药剂稳定化处理及机理研究

【作者】 郑庆锋；

【导师】 韩怀芬；

【作者基本信息】 浙江工业大学 ， 环境工程， 2003， 硕士

【摘要】 药剂稳定化是近年来发展的一种新型的危险废物无害化处理技术，其主要作用是通过在废物中添加某些化学药剂，使之与废物中的有害成分发生化学反应，从而破坏危险废物中的有害成分，使之形成化学特性稳定的难溶化合物，达到防止有害物质浸出的目的。本文通过单因素实验、正交实验确定了高分子螯合剂合成的最佳工艺为：体系pH值9～10；HTA/[S]=1.2（摩尔比）；反应温度为50℃；反应时间为4h，得到取代度为0.568的含氮淀粉醚高分子螯合剂。 研究了pH值、药剂投加量、初始浓度、接触时间以及其它金属共存时等对重金属离子吸附的影响，并且考察了高分子螯合剂对水溶液里的重金属离子的吸附能力。结果表明，当pH=6、投加量为0.5g/L、接触时间t=30min时，对Cu²⁺和pb²⁺的去除率分别为99.46％和97.95％，但对Cr³⁺和Cd²⁺则较低，分别为89.62％和75.12％。结果还表明，取代度越高的螯合剂，对重金属去除率越高。 然后再用取代度为0.568的含氮淀粉醚高分子螯合剂应用于铬渣的固化实验，对固化体的浸出毒性、表面浸出率、抗压强度等指标进行了测试。结果表明，添加螯合剂后的固化体其浸出毒性比不加螯合剂的降低了66.4％之多，远远小于国家标准的1.5mg／L；28天后的表面浸出率可达10^-6数量级；抗压强度有所下降，但28天养护后的抗压强度都大于30MPa，满足填埋或建筑综合利用的强度要求。 最后对捕集重金属的多级吸附理论模型进行了探讨和验证，结果表明多级吸附过程比单级吸附过程对重金属的去除率明显提高，并运用红外光谱定性地对反应机理进行了探索。更多还原

【Abstract】 Medicament stability is a new technique developed in recent years which deals with hazardous waste. Its process is first to add chemical medicaments to waste, then hazardous waste components react with chemical medicaments, so some insoluble compounds are formed to prevent hazardous components leaching from waste. In this paper, the optimum synthesizing process of macromolecule chelate complex is decided (pH:9~10; HTA/[S] = 1.2 (molar ratio); reaction temperate: 50癈; reaction time: 4h),and the substitute degree of chelate complex is 0.568.The influences of pH, quantity of chelate, initial concentration, contacting time and other metal ions coexisting on chelate adsorbing heavy metal are studied. The results indicate that the removal ratios of Cu2+ and Pb2+ are 99.46%, 97.95% respectively, but those of Cr3+and Cd2+ are lower, 89.62% and 75.12% respectively.The properties of waste forms containing chelate are tested. The results show, compared with sample without chelate, toxicity of leachate of waste forms reduces by 66.4%, and far lower than 1.5mg/L. After 28 days, the scalar of surface leaching rate reach 10"6. The compressive strength of waste forms decreases with chelate added, but is still more than SOMPa after 28 days, meeting all the conditions in general construction or landfill.The kinetic of absorbing heavy metals is also discussed. The results indicate that removal ratio of heavy metals in multi-stage adsorption process is more than that in single-stage adsorption process. At the same time IR is applied to study reaction mechanism qualitatively.更多还原