Fate of Harmful Chemical Substances in Landfill and Establishment of Safety Evaluation Method for leachate

自从发现地下水受到对人体有害的化学物质的污染后，环境标准中增加了农药、有机溶剂等化学物质作为控制对象。垃圾填埋场及周边地区的地下水中也检测出塑料中的增塑剂和阻燃剂，渗滤液的安全性成为公众关注的问题。因此，我们选择了诱变剂试验作为有害化学物质特别是致癌物质的检测方法，并对渗滤液的诱变性进行了研究。结果表明，诱变剂试验是一种有效的渗滤液安全指标，但诱变剂试验中存在的一些问题，如诱变剂的提取和抑制剂的去除等，尚需进一步研究。此外，诱变剂可通过废物的生物分解产生和降解。因此，我们试图解决这些问题，并清除诱变剂在垃圾填埋场的命运。结果表明：1）调节pH值至2时，大部分致突变物被浓缩，2)蓝色粘胶纤维吸附不能将所有渗滤液中的致突变物富集，3)溶剂萃取法和CSP树脂吸附法对渗滤液中致突变剂的回收率差异不大，4)内标法作为诱变剂试验的校正方法可能无效，5)诱变剂试验中的抑制剂可用10%2PrOH/己烷去除。6)垃圾填埋层中诱变剂的产生和降解是通过垃圾在好氧条件下的生物降解，特别是硝化过程发生的。7)诱变剂不仅由硝化作用产生，而且由反硝化作用产生。8)结果表明，含垃圾填埋层中可能产生硝基芳烃作为诱变剂。

Since the pollution of underground water by the chemcial substances, which are harmful to man, was found, some chemical substances such as pesticides and organic solvents have been added as the control subjects of environmental standard. The plasticizers and fire retardants of plastics also were detected in the undergraoud water in the landfill site and the surrounding areas and the safety of leachate become the public concern. So, we selected a mutagen test as the detection method of harmful chemical substances, especially the carcinogen, and surveyed the mutagenicity of leachate. From the results, it was cleared that the mutagen test was useful method as the safety indicator for leachate, and that some problems opf mutgen test, such as the extraction of mutagen adn teh removal of inhibitermmust be solved. Moreover, the mutagen may be produced and degraded by the biological decomposition of wastes. So, we tried to solve these problems and to clear the fate of mutagen in the landfill site. The results of this study are as follows ;1) Most of mutagens were concetrated by the adjustment of pH to 2.,2) Blue rayon adsorption could not concentrated the mutagens from all of leachate.,3) On the recovery percentages of mutagen from leachate, there were not great difference between the solvent extraction and CSP resin adsorption.,4) The internal standard method may be unuseful as a correction method against the inhibitation for the mutagen test.,5) The inhibiters of mutagen test can be removed by 10%2PrOH/Hexane.,6) The production and degradation of mutagens in the landfill layr occur by the biodegradation of wastes in an aerobic condition, especially the nitrification process.,7) The mutagens were not only produced by the nitrification, but also the denitrification.,8) It is suggested that Nitroarene may by produced as the mutagen in the landfill layr contained incineration residues.