三峡库区垃圾焚烧飞灰中汞的污染特性

Pollution characteristics of mercury in incineration fly ash of municipal solid waste in Three Gorges region

研究了三峡库区垃圾焚烧飞灰中汞在不同粒径下的分布特征、不同浸出时间、液固比和不同酸度下的浸出规律、浸出毒性及飞灰中汞的不同存在形态的含量。结果表明三峡库区垃圾焚烧飞灰中汞平均含量为8.52mg/kg,粒径在<100μm范围内的飞灰中汞含量较高,且汞的含量随着飞灰颗粒尺寸的减小,呈增加趋势。汞的浸出与环境条件密切相关:汞的浸出量随pH值及液固比(L/S)的增加而增大,随时间的延长而减少。形态分析表明飞灰中汞的可氧化态及残渣态含量都较高,而弱酸提取态和可还原态含量则相对较低。

This study investigates the mercury distribution characteristics at different particle sizes, leaching characteristics with different impact factor such as the different time, the different ratio of liquid to solid and the different acidity, leaching toxicity and speciation of mercury in Municipal Solid Waste Incineration （MWSI） fly ash in Three Gorges area. The results show that the average content of mercury in the fly ash is 8.52 mg ·kg^-1. The content of mercury in the fly ash is higher at the particle size of 100μm, and which increases with the decreas of the ash particle size. Mercury leaching content closely relates to environmental conditions. The leaching content of mercury increases with the increase of pH and L/S, while it decreases with the leaching time. The content of mercury at oxidable form and the residue form are high, and whith at exchangeable form and reducible form is relatively low.