城市生活垃圾焚烧处理过程中重金属迁移规律研究

通过采集厦门2个垃圾焚烧发电厂进厂垃圾、渗滤液、飞灰、炉渣和烟气样品，分析垃圾组成成分及各组分的重金属含量，结果表明，垃圾中以厨余、橡塑类和纸类为主，共占到垃圾干基的78．08％，重金属含量大小次序为Zn〉Cu〉Pb〉Cr〉Ni〉Cd〉Hg；垃圾渗滤液中除Zn外，其他金属的含量都较低，一厂渗滤液中重金属Ni、Zn迁移量较大，分别达到24．46％和8．52％。二厂渗滤液中重金属的迁移有相同的趋势，但含量相对较高。垃圾焚烧后其重金属主要分布在飞灰和废渣中，烟气中的含量非常少，不同金属的含量均有差别，这与金属的性质有很大关系；通过浸出毒性分析，飞灰中重金属酸溶态含量多，容易浸出，属于危险废物。同时，不同烟气处理工艺产生的飞灰的重金属浸出量有很大差别。

Study on the migration rule of heavy metal in waste incineration

Garbage, leachate, fly ash, slag, and gas from two garbage incinerators in Xiamen were collect- ed and analyzed. The results showed that kitchen wastes, rubber and plastic, and paper are the significant com- ponents of garbage which account for 78.08%. In term of the heavy metal contents in the samples, the order is Zn 〉 Cu 〉 Pb 〉 Cr 〉 Ni 〉 Cd 〉 Hg. More specifically, all the contents of heavy metal in the leachate are all quite low except Zn. Higher proportion of migration of Ni and Zn are found in the first plant then in the second plant which are 24.46% and 8.52% , respectively. The heavy metals have the same trend of migration in the second plant but are with higher contents. Fly ash and slag are found with more heavy metals than the gas. The contents of different heavy metals are quite different due to the different properties of them. Ash is classified as hazardous waste because it is with high concentrations of heavy metals which are easily extracted. Furthermore, the extraction concentrations of heavy metals significantly depend on the gas processing techniques.