温度对污泥焚烧残渣中重金属形态分布及残渣综合毒性的影响  

Effect of temperature on the heavy metal fraction distribution and comprehensive toxicity on incineration residue of sewage sludge

作　　者：刘淑静[1] 李爱民[1] 袁维波[1] 

机构地区：[1]大连理工大学环境与生命学院工业生态与环境工程教育部重点实验室,辽宁大连116024

出　　处：《安全与环境学报》2008年第1期43-47,共5页Journal of Safety and Environment

基　　金："985工程"二期项目(1000-872A01)

摘　　要：通过实验考察了干污泥在固定床焚烧炉中停留20min,温度分别为500℃、700℃和900℃的焚烧残渣中重金属(Cr、Cu、Ni、Zn、Pb、Cd)的残留特性及形态分布规律。在实验温度范围内,重金属的残留率因元素和焚烧温度而异,Cu的残留率最高在80%以上,Cd的最低,900℃时仅为3.4%;焚烧残渣中各重金属在稳定态的分布比例均较干污泥中有显著提高。提出了用于重金属毒性定量分析的指标——重金属综合毒性指数,并采用该指数对污泥和残渣中重金属的综合毒性进行了评价。结果显示,单位质量污泥焚烧后的各残渣中重金属综合毒性均较干污泥小且随焚烧温度升高而降低,焚烧能够实现一定程度的无害化;并且,单位质量残渣中重金属的综合毒性也随焚烧温度的升高而降低。This paper is to present a laboratory examination results over the influence of incineration of sludge residue at different temperatures on the behaviour of heavy metal fractions （including heavy metal fraction distribution and remaining features） at Dalian Development Zone Wastewater Treatment Plant. For this purpose, we have done a series of experiments in an incinerator in the following three temperatures, that is, at 500 ℃, 700℃ and 900℃ respectively. As a means for analysis, we have adopted the Perkin Elmer Analyst 700 Atomic Absorption Spectrometer for measuring the concentration of heavy metals fractions in dry sludge and its incineration residue. The results of our analysis suggest that the sewage sludge was found containing significant amounts of heavy metal, such as Cr, Cu, Ni, Zn, Pb and Cd, with various remaining percentages, though. For example, in a kind of our sampling sludge, its remaining content was 80% of Cu but only 3.4% of Cd when incinerated at the temperature of 900℃. It was also found that the portion of remaining metals in the dry sludge would reveal a remarkable steady-increase tendency after incineration. Another point of our research results is that we have pmpnsed the problem of the heavy metal comprehensive toxicity index, which can be adopted for quantitative analysis. It is in this index that all the likely factors that may influence the bioavailability of various heavy metal fractions are included, such as the heavy metal toxicity differences, the heavy metal concentrations in the various forms and the fractions differences on the heavy metal comprehensive toxicity. Besides, it is also this index that exhibits abroad applicability, which can be used to assess the heavy metal comprehensive toxicity in all kinds of environmental media. Thus, in this paper, we have applied this index for evaluating the toxicity of heavy metals in the sludge and its residue after incineration. As a result of our analysis, we have found that the comprehensive toxicity in sludge residue prov

关 键 词：环境工程 污泥焚烧 Tessier五态分析法 重金属形态 重金属综合毒性指数 

分 类 号：X703.1[环境科学与工程—环境工程]