类柱试验中焚烧飞灰浸出特性研究

Characteristics of MSWI fly ash leachate of the column-like leaching test

通过类柱试验研究焚烧飞灰的浸出规律。结果表明,随着流入系统中酸溶液体积的增加,系统pH先升高而后下降;在整个系统中,Ca的浸出质量浓度很高;Cr的浸出质量浓度要高于Cd、Cu、Zn、Pb和Ni,随着反应时间的推进,它们的浸出质量浓度都随着流入系统中酸溶液体积的增加而逐渐降低;在同一时间浸出质量浓度曲线上,从系统的上游到下游,浸出质量浓度呈增加趋势,如Cu的浸出质量浓度在系统上游(单元1)为60.2μg/L,而在系统下游(单元10)为158.0μg/L。

The column-like leaching test runs were conducted to simulate leaching of a Shanghai municipal solid waste incineration （MSWI） fly ash. The test employed 100 mL of acidic water （pH ： 2） to perform serial leaching in 10 plastic bottles which were each filled with 100 g of the fly ash sample. After mixing the water and the fly ash in the first bottle for 48 h, the leachate was transferred to the second bottle to leach its fly ash; 100 mL of fresh acidic water was added to the first bottle to continue the serial leaching test. The leaching results showed that the leachate pH increased initially then declined. The leachate had a very high Ca concentration and that it had more Cr than Cd,Cu, Zn, Pb and Ni. After an extended period of leaching, all metal concentrations of the leachate declined. Concentrations of all soluble species increased with more leaching in the serial bottles; for example, the 2-day leaching Cu concentration increased from 60. 2 μg/L in the first bottle to 158.0 μg/L in the last bottle.