学术
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。[著者文摘]
关 键 词:
文章出处:
《安全与环境学报》-2008年8卷1期 -43-47页
栏目信息:
分 类 号:
文献标识码:
A
文章编号:
1009-6094（2008）01-0043-05
Effect of temperature on the heavy metal fraction distribution and comprehensive toxicity on incineration residue of sewage sludge
LIU Shu-jing, LI Ai-min, YUAN Wei-bo （ School of Environmental ＆ Biological Science ＆ Technology, Dalian University of Technology, Industrial Ecology and Environmental Engineering Key Laboratory of Ministry of Education, Dalian 116024, Liaoning, China）
Abstract:
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 proves lower than it in dry sludge. This tendency of toxicity decrease would continue with the increase of incineration temperature. Therefore, it can be concluded that high temperature treatment of the sludge is favourable for reducing the environmental pollution to a certain extent. Moreover, the toxicity in the unit mass of sludge residue also tends to decrease with the temperature rising.[著者文摘]
Key words:
environmental engineering; incineration of sewagesludge; five-step method of Tessier; heavy metal fraction; heavy metal comprehensive toxicity index
基金资助:
“985工程”二期项目（1000-872A01）
更多>>免费文章
cqvip.com