摘要
采用现场采样及室内试验方法,研究了生活垃圾渗滤液对垃圾堆填区周边土壤铵态氮吸附能力的影响。结果表明,垃圾渗滤液进入土壤后,大量共存离子的竞争吸附减弱了土壤胶体对铵态氮的吸附能力,而且高浓度铵态氮的存在抑制了土壤的硝化作用,从而使大量的铵态氮未能被土壤胶体吸附转化就随渗滤液继续迁移地下水中,最终导致地下水严重的铵态氮污染。
We studied the current state of nitrogen contamination in groundwater in a landfill site lied in western suburb of Beijing. The results showed that, there has been a large amount of ammonia- nitrogen in landfill leachate and the contamination of ammonia- nitrogen was the main form of pollution in groundwater of landfill. To further indicate the results, a set of experiments was conducted to study the effects of waste leachate on the ammonia- nitrogen adsorption ability in the soil nearby municipal waste landfill. The experiments involved in adsorption of ammonia- nitrogen of coexistent ions in leachate and different organic matter contents and different ammonia- nitrogen contents of soil. The results showed that when some metal ions and ammonia- nitrogen in the leachate moved into the soil along with leachate, soil colloids prone to adsorb coexistent ions such as Fe2+ , Mn2+ , Ca2+ , Cd2+ rather than . After adsorbing these ions, the ammonia- nitrogen adsorption ability of soil reduced. Moreover, the organic matter content in the soil around a landfill site was higher than unpolluted soil by leachate. A complex function of organic matter and soil minerals reduced the exchange sites for ammonia- nitrogen. Therefore when large amounts of organic matter and metal ions coexisted with ammonia- nitrogen in the soil, it could decrease the adsorption ability of soil to ammonia- nitrogen. In addition, the high concentration of ammonia- nitrogen in the landfill the soil could inhibit the nitrifying microorganisms in the soil and decreased the transformation speed from ammonia- nitrogen to nitrate, resulting in that the nitration of soil has been restrained.Accordingly, a great deal of ammonia- nitrogen moved along with waste leachate into the groundwater before they had been adsorbed or conversed, which resulted in the serious ammonia- nitrogen pollution in landfill groundwater.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2004年第3期503-507,共5页
Journal of Agro-Environment Science
基金
"十五"国家科技攻关计划重大课题(2002BA516A03)
关键词
垃圾渗滤液
铵态氮
吸附能力
土壤
地下水
leachate
ammonia- nitrogen
landfill soil
landfill
groundwater
