Abstract:

The amount of urban and industrial sewage generated in China has reached 7.34×10¹⁰ t/a, and the number of sludge produced by its treatment has reached 7.29×10⁷ t/a. The main utilization methods of sludge are land application, incineration for power generation and for building materials. Heavy metals, especially Cr, Cu, Zn, Ni etc., have a great impact on these reuse processes. The sludge treatment mainly adopts pyrolysis technology. Heavy metals are concentrated in the pyrolysis residue during the pyrolysis process. Explaining the speciation distribution of heavy metals in the pyrolysis residue is of great significance to the reuse process. Based on the modified European Community Bureu of Reference (BCR) sequential extraction method, the speciation distribution of heavy metals in the sludge pyrolysis residue is summarized, the effect of pyrolysis conditions (pyrolysis temperature, residence time and catalyst), co-pyrolysis and pretreatment on the speciation distribution of heavy metals in the pyrolysis residue is described, and the future research trends of heavy metals in sludge pyrolysis residues are discussed.

Key words: pyrolysis, heavy metals, catalyst, additive, stability, speciation distribution

摘要：

目前，我国城市及工业污水产生量已达7.34×10¹⁰ t/a，对其处理产生的污泥量达7.29×10⁷ t/a。污泥的主要去向为土地利用、焚烧发电和建材利用等。在这些再利用过程中，重金属特别是Cr、Cu、Zn、Ni等对其再利用影响较大。污泥处理多采用热解处理，重金属在处理过程中会富集在热解残渣中。阐释重金属在热解残渣中的形态分布，对于其再利用过程意义重大。本文以改进的欧共体物质标准局(BCR)连续提取法为基础，总结了污泥热解残渣中重金属的形态分布，阐述了热解工况(热解温度、停留时间、催化剂)、共热解及预处理对热解残渣中重金属形态分布的影响，探讨了污泥热解残渣中重金属未来的研究趋势。

关键词: 热解, 重金属, 催化剂, 添加剂, 稳定性, 形态分布