市政污泥热解过程颗粒物中重金属分布

以深圳市某污水处理厂的污泥为原料，研究了污泥热解过程产生的颗粒物及其中8种重金属的分布规律.结果表明，颗粒物的生成速率分别在400~600℃和1000℃保温30min的两个区间内达到峰值.8种重金属的热挥发性由大到小依次为Cd > Zn > As > Pb > Mn > Ni > Cu > Cr，而其在颗粒物中富集能力大小顺序为Pb > As > Mn > Zn > Cd > Ni > Cr > Cu.颗粒物重金属在热解气中的体积浓度随热解过程呈上升趋势，Zn和Cd则在升温阶段（1000℃以前）达到峰值后开始降低.研究表明，污泥热解颗粒物富集的重金属超标，因而污泥热解尾气颗粒物的去除装置十分必要.

Study on heavy metals in particulate matter of municipal sewage sludge pyrolysis

In this study, sewage sludge from a waste water treatment plant in Shenzhen was used for pyrolysis to investigate the characteristics of generated particulate matter (PM) and the change of 8heavy metals. The results showed that the PM production rate peaked twice at 400~600℃ and at the first 30minutes holding at 1000℃, respectively. The thermal volatility of the 8heavy metals was as follows:Cd > Zn > As > Pb > Mn > Ni > Cu > Cr. And the enrichment capacities of the 8heavy metals in the PM followed the order:Pb > As > Mn > Zn > Cd > Ni > Cr > Cu. The volumetric heavy metals concentration generally showed an increase trend with the pyrolysis process. However, Zn and Cd decreased after peaking at the stage of temperature rising (before 1000℃). The research suggests that the heavy metals enriched during sludge pyrolysis and the generated PM exceeds the standard value. Therefore, the exhaust PM removal device is necessary.