Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi, UP 221005, India.
Rev Environ Contam Toxicol. 2011;214:41-61. doi: 10.1007/978-1-4614-0668-6_3.
In the present review, we address the effects of sewage sludge amendment on soil physicochemical properties and on soil microbial biomass. Sewage sludge is a by-product of sewage treatment processes and is increasingly applied to agricultural lands as a source of fertilizer, and as an alternative to conventional means of disposal. The particular characteristics of sewage sludge depend upon the quality of sewage from which it is made, and the type of treatment processes through which it passes. Sewage sludge may substitute for inorganic fertilizers because it is rich in organic and inorganic plant nutrients. However, the presence of potentially toxic metals and pathogens in sewage sludge often restricts its uses. Ground water and food chain contamination resulting from sewage sludge amendment is one major concern worldwide. The health of soils is represented by a composite of their physical, chemical and biological properties. Amending soil with sewage sludge modifies the physicochemical and biological properties of soils. Perhaps the central constituent of soil that is important in the context of sewage sludge amendment is microbial biomass. Soil microbial biomass, the key living part of the soil, is very closely associated with the content of organic matter that exists in arable agricultural soils. When sewage sludge is land-applied, soil enzyme activities may be directly or indirectly affected by the presence of heavy metals. In several studies, results have shown that sewage sludge amendment increased soil microbial and soil enzyme activities; however, reduction in soil enzyme activity has also been reported. When incubation periods of sewage sludge were longer, heavy metal bioavailability increased. Soil pathogenic activity has also been reported to increase as a result of land application of sewage sludges. The level of pathogens in treated sewage sludge (biosolids) depends on the processes used to treat wastewater and sewage sludge. Agricultural application of sewage sludge may result in the transport of pathogens through aerosols downwind of sludge storage or dispersal sites, may contaminate ground water, stock ponds, or may produce food chain contamination from eating food grown in sludge-treated land.
在本综述中，我们探讨了污水污泥改良对土壤理化性质和土壤微生物生物量的影响。污水污泥是污水处理过程的副产品，越来越多地应用于农业土地作为肥料来源，并作为传统处理方法的替代方法。污水污泥的特殊特性取决于其来源的污水质量以及经过的处理过程类型。污水污泥因其富含有机和无机植物养分，可替代无机肥料。然而，污水污泥中存在潜在毒性金属和病原体通常限制了其用途。污水污泥改良导致地下水和食物链污染是全世界关注的主要问题之一。土壤健康由其物理、化学和生物特性的综合表现来代表。用污水污泥改良土壤会改变土壤的理化和生物特性。也许在污水污泥改良的背景下，土壤中最重要的中心成分是微生物生物量。土壤微生物生物量是土壤的关键活部分，与可耕地土壤中存在的有机物含量密切相关。当污水污泥施用于土地时，土壤酶活性可能会直接或间接地受到重金属的存在的影响。在几项研究中，结果表明，污水污泥改良增加了土壤微生物和土壤酶活性；然而，也有报道称土壤酶活性降低。当污水污泥的培养期更长时，重金属的生物利用度增加。由于施用污水污泥，土壤的致病性活动也有所增加。经处理的污水污泥（生物固体）中的病原体水平取决于用于处理废水和污水污泥的过程。农业应用污水污泥可能导致病原体通过气溶胶在污泥储存或分散地点下风处传播，可能污染地下水、储水池，或可能导致食用在污泥处理土地上种植的食物的食物链污染。
