污泥热解与燃烧促进重金属固定化  

Sludge pyrolysis and combustion promote the immobilization of heavy metals

作　　者：张慷 邓浩旺 田科 ZHANG Kang;DENG Haowang;TIAN Ke(College of Environment and Resources,Xiangtan University,Xiangtan 411105,China)

机构地区：[1]湘潭大学环境与资源学院,湖南湘潭411105

出　　处：《湘潭大学学报（自然科学版）》2022年第5期102-110,共9页Journal of Xiangtan University(Natural Science Edition)

基　　金：国家自然科学基金项目(21806137)。

摘　　要：该文以温度和升温速率为主要变量,以制革污泥为材料,通过热解和燃烧实验制备生物炭,并从中选取危害性较大的Cu、Pb、Ni和Cr作为主要评价指标,研究反应过程中Cu、Pb、Ni和Cr的迁移和形态分布特性.利用四步提取法(BCR)提取各重金属形态,得到其形态分布变化规律,同时采用消解法对比分析污泥和衍生炭中重金属总量,运用生物炭中重金属的残留率研究其挥发程度.结果表明,Ni在燃烧过程中的残留率随着温度的升高而增加,而生物炭中Pb、Cr和Cu残留率随着温度的升高而逐渐降低.研究重金属形态分布特性发现,四种重金属形态分布情况各不相同,但转化路径相似.在400~600℃间由不稳定态向稳定形态转化,但当温度升高至800℃时,F3和F4形态逐步分解破碎,出现了不同程度的F1和F2形态.在热解和燃烧过程中当温度为600℃时,重金属中易迁移的F1和F2形态比例均为最低值.通过对比不同气氛下Pb的形态变化,发现氧气的存在有利于Pb的稳定.该文为制革污泥处理资源化提供参考.In this study,temperature and heating rate were used as the main variables,and tannery sludge was used as the material to prepare biochar through pyrolysis and combustion experiments,and the more harmful Cu,Pb,Ni and Cr were selected as the main evaluation indicators.The migration and shape distribution characteristics of Cu,Pb,Ni and Cr during the reaction.The four-step extraction method(BCR)was used to extract the forms of heavy metals,and the law of their morphological distribution changes was obtained.At the same time,the digestion method was used to compare and analyze the total amount of heavy metals in sludge and derived char,and the residual rate of heavy metals in biochar was used to study the degree of volatilization.The results show that the residual rate of Ni in the combustion process increases with the increase of temperature,while the residual rate of Pb,Cr and Cu in biochar gradually decreases with the increase of temperature.Studying the distribution characteristics of heavy metals found that the distribution of the four types of heavy metals is different,but the conversion path is similar.Between 400℃and 600℃,it changed from an unstable state to a stable state,but when the temperature increased to 800℃,the F3 and F4 forms gradually decomposed and broke,and different degrees of F1 and F2 forms appeared.In the pyrolysis and combustion process,when the temperature is 600℃,the proportions of F1 and F2 forms in heavy metals that are easy to migrate are the lowest value.By comparing the morphological changes of Pb in different atmospheres,it is found that the presence of oxygen is beneficial to the stability of Pb.This research provides a reference for resource utilization of tannery sludge treatment.

关 键 词：制革污泥 热分解 重金属 迁移 形态分布 

分 类 号：X131[环境科学与工程—环境科学]