盐酸和硝酸对垃圾焚烧飞灰的浸出特性研究

Study on the Leaching Characteristics of Heavy Metals from Municipal Solid Waste Incineration Fly Ash by Hydrochloric and Nitric Acids

以垃圾焚烧飞灰作为研究对象,采用硝酸和盐酸两种浸取剂处理垃圾焚烧飞灰,为获取更佳的浸出效果,考察了两种酸在不同初始pH和液固比下飞灰的浸出特性。结果表明:飞灰中重金属在强酸条件下更易浸出,初始pH值对硝酸的影响更显著,盐酸在较宽初始pH值下,可获得较高的浸出率;除Pb、Cd和Zn外,浸取剂的液固比的增加有利于飞灰中重金属浸出率的提升;盐酸浸取剂可提升飞灰中Pb的浸出率,最高浸出率达到40.40%。

The leaching characteristics of municipal solid waste incineration fly ash under the conditions of different initial pH values and liquid/solid ratios using nitric acid and hydrochloric acid as assisting agents were studied.The results show that the leaching rates of heavy metals in flying ash were strongly affected by initial pH values.The higher leaching rates of heavy metals in flying ash were obtained by lower initial pH value from nitric acid and by wider initial pH value from hydrochloric acid.The increase of the liquid-solid ratio of the leaching agent is beneficial to the improvement of the heavy metal(not including Pb,Cd and Zn)leaching rate in flying ash.The leaching Pb rate in flying ash can be increased by hydrochloric acid extract,with the highest leaching rate being 40.40%.