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讨论了以河道底泥和生活污泥为原料烧制陶粒比表面的测定原理、方法和结果,并对生活污泥添加量、粘结刑添加量和烧结温度对陶粒比表面的影响作了进一步分析。 相似文献
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Fate of ah receptor agonists during biological treatment of an industrial sludge containing explosives and pharmaceutical residues 总被引:1,自引:0,他引:1
Gustavsson LK Klee N Olsman H Hollert H Engwall M 《Environmental science and pollution research international》2004,11(6):379-387
GOAL, SCOPE AND BACKGROUND: Sweden is meeting prohibition for deposition of organic waste from 2005. Since 1 million tons of sludge is produced every year in Sweden and the capacity for incineration does not fill the demands, other methods of sludge management have to be introduced to a higher degree. Two biological treatment alternatives are anaerobic digestion and composting. Different oxygen concentrations result in different microbial degradation pathways and, consequently, in a different quality of the digestion or composting residue, It is therefore necessary to study sludge treatment during different oxygen regimes in order to follow both degradation of compounds and change in toxicity. In this study, an industrial sludge containing explosives and pharmaceutical residues was treated with anaerobic digestion or composting, and the change in toxicity was studied. Nitroaromatic compounds, which are the main ingredients of both pharmaceutical and explosives, are well known to cause cytotoxicity and genotoxicity. However, little data are available concerning sludge with nitroaromatics and any associated dioxin-like activity. Therefore, we studied the sludge before and after the treatments in order to detect any changes in levels of Ah receptor (AhR) agonists using two bioassays for dioxin-like compounds. METHODS: An industrial sludge was treated with anaerobic digestion or composting in small reactors in a semi-continuous manner. The same volume as the feeding volume was taken out daily and stored at -20 degrees C. Sample preparation for the bioassays was done by extraction using organic solvents, followed by clean up with silica gel or sulphuric acid, yielding two fractions. The fractions were dissolved in DMSO and tested in the bioassays. The dioxin-like activity was measured using the DR-CALUX assay with transfected H4IIE rat hepatoma pGudluc cells and an EROD induction assay with RTL-W1 rainbow trout liver cells. RESULTS AND DISCUSSION: The bioassays showed that the sludge contained AhR agonists at levels of TCDD equivalents (TEQs) higher than other sludge types in Sweden. In addition, the TEQ values for the acid resistant fractions increased considerably after anaerobic digestion, resulting in an apparent formation of acid resistant TEQs in the anaerobic reactors. Similar results have been reported from studies of fermented household waste. There was a large difference in effects between the two bioassays, with higher TEQ levels in the RTL-W1 EROD assay than in the DR-CALUX assay. This is possibly due to a more rapid metabolism in rat hepatocytes than in trout hepatocytes or to differences in sensitivities for the AhR agonists in the sludge. It was also demonstrated by GC/FID analysis that the sludge contained high concentrations of nitroaromatics. It is suggested that nitroaromatic metabolites, such as aromatic amines and nitroanilines, are possible candidates for the observed bioassay effects. It was also found that the AhR agonists in the sludge samples were volatile. CONCLUSIONS: The sludge contained fairly high concentrations of volatile AhR agonists. The increase of acid resistant AhR agonist after anaerobic digestion warrants further investigations of the chemical and toxic properties of these compounds and of the mechanisms behind this observation. RECOMMENDATION AND OUTLOOK: This study has pointed out the benefits of using different types of mechanism-specific bioassays when evaluating the change in toxicity by sludge treatment, in which measurement of dioxin-like activity can be a valuable tool. In order to study the recalcitrant properties of the compounds in the sludge using the DR-CALUX assay, the exposure time can be varied between 6 and 24 hours. The properties of the acid-resistant AhR agonists formed in the anaerobic treatment have to be investigated in order to choose the most appropriate method for sludge management. 相似文献
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介绍了石材废水集约化处理的一个成功实例,分析、总结了混凝沉淀法处理石材废水的可行性及注意事项,并通过比较得出石材废水集约化处理较分散治理具备明显优势的结论. 相似文献
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含重金属水处理污泥的固化和浸出毒性研究 总被引:2,自引:0,他引:2
工业危险固体废物在进行安全填埋前需要进行固化稳定处理。针对电镀厂和皮革厂含重金属的水处理污泥 ,用不同比例的水泥、粉煤灰进行固化稳定处理。考虑酸雨环境 ,浸出实验采用TCLP标准。电镀厂污泥单独固化时 ,其浸出液中铜离子浓度由 78 0mg/L下降到 1 5mg/L ;镍离子浓度由 2 2 4 5mg/L下降到 2 2 2mg/L ,高于危险废物允许进入填埋区 15mg/L的控制限值。电镀厂污泥与皮革厂污泥混合后固化 ,浸出液毒性明显降低。铜离子的浸出浓度降低到1 98mg/L ,镍离子降低到 4 10mg/L ,总铬降低到 0 4 0mg/L ,各项指标均低于国家危险废物允许进入填埋区的控制限值 ,可安全填埋。 相似文献
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