施用城市污泥对土壤生态系统影响的研究进展

城市污泥的合理处置已成为目前环境科学研究领域中的重要课题。因污泥富含有机质和有效营养成分，对土壤改良有积极的促进作用，所以污泥的土地利用普遍被认为是一种积极、有效的处置方式。鉴于此，本文就国内外施用城市污泥对土壤生态系统的．影响及相关的过程和机理进行了综述。结果显示，施用污泥可改善土壤理化性质，提高土壤有机质和氮、磷等养分元素的含量，其改良作用因污泥类型而异。污泥对土壤重金属的积累有所影响，特别是在酸雨频发地区或者长期施用污泥，可能会带来重金属Gu污染的环境风险。污泥普遍有利于提高土壤酶活性，譬如土壤淀粉酶、脲酶和蔗糖酶活性，但污泥施用过量或时间延长，则会抑制多酚氧化酶和磷酸酶的活性，而污泥对过氧化氢酶的影响则不大。污泥对土壤微生物特性短期内有积极的影响，但长期则有负面作用。施用污泥可导致土壤动物活性的增加，但也会对一些土壤动物产生毒性，譬如异壳介虫属和弹尾目昆虫，而且污泥毒性不仅取决于污泥用量，土壤类型也起着重要作用。基于上述分析和评述，提出了未来研究展望如下：（1）针对污泥施用后土壤生态系统生物、物理和化学过程和机理进行系统、综合的基础研究；（2）对污泥土地利用进行长期的系统定位试验和环境监测，并对之进行环境风险评价；（3）对污泥稳定化处理技术的创新及其应用研究。

Review on the effects of municipal sewage sludge application on soil ecosystem properties

Concerning about the appropriate disposal of municipal sewage sludge has recently become a critical issue in environmental science research. The application of municipal sewage sludge in field has generally been recognized a positive and effective practice for disposal of sewage sludge, which could provide an additional organic amendment in improving soil properties due to the sludge containing useful components including abundant organic matter and other available nutrient. Recent research advance concerning the effects of municipal sewage sludge application on soil ecosystem, related processes, and its mechanisms is reviewed in this paper. Municipal sewage sludge application improves the soil physicochemical properties with increased the soil organic matter content and nutrition elements, particularly nitrogen and phosphorus, that the soil amendment extent depending on the types of sludge. The heavy metals accumulation can be affected by sewage sludge, especially, in acid rain-stricken area or through long-term sludge application, an environmental risk of metal Cu pollution likely could be magnified. Generally, sludge amendment can stimulate soil enzyme activity, such as amylase, urease and sucrase, but inhibit the activities of polyphenol oxidase and phosphatase in the case of excessive or long-term application, with slightly affecting on catalase activity. Short-term sludge application has a positive effect on soil microbial characteristics, but long-term sludge use may cause a negative effect. Adding sewage sludge increases soil faunal activity, meanwhile results in the toxicity of some soil animals, such as heterocypris incongruens and collembolans, the toxicity magnitude depending on sludge dose and soil types. Based on the above analysis, the further research might be expected as follows： （1） The integrated biological, chemical, physical processes and the mechanisms of sludge amended soil ecosystem should be researched; （2） Long-term ecosystem location testing and environmental monitoring should be conducted to evaluate environmental risk of municipal sewage sludge application; and （3） Innovating study on sludge stabilization technology and its application also should be strengthened.