Pepper Ian L, Zerzghi Huruy, Brooks John P, Gerba Charles P
The Univ. of Arizona, Environmental Research Laboratory, 2601 E. Airport Drive, Tucson, AZ 85706, USA.
J Environ Qual. 2008 Sep-Oct;37(5 Suppl):S58-67. doi: 10.2134/jeq2007.0321.
Land application of Class B biosolids is routinely undertaken in the United States. However, due to public concern over potential hazards, the long-term sustainability of land application has been questioned. Thus, the objective of this review article was to evaluate the sustainability of land application of Class B biosolids. To do this we evaluated (i) the fate and transport of potential biological and chemical hazards within biosolids, and (ii) the influence of long-term land application on the microbial and chemical properties of the soil. Direct risks to human health posed by pathogens in biosolids have been shown to be low. Risks from indirect exposure such as aerosolized pathogens or microbially contaminated ground water are also low. A long-term land application study showed enhanced microbial activity and no adverse toxicity effects on the soil microbial community. Long-term land application also increased soil macronutrients including C, N, and, in particular, P. In fact, care should be taken to avoid contamination of surface waters with high phosphate soils. Available soil metal concentrations remained low over the 20-yr land application period due to the low metal content of the biosolids and a high soil pH. Soil salinity increases were not detected due to the low salt content of biosolids and irrigation rates in excess of consumptive use rates for cotton. Our conclusion, based on these studies, is that long-term land application of Class B biosolids is sustainable.
在美国，B类生物固体的土地施用是常规操作。然而，由于公众对潜在危害的担忧，土地施用的长期可持续性受到了质疑。因此，这篇综述文章的目的是评估B类生物固体土地施用的可持续性。为此，我们评估了：（i）生物固体中潜在生物和化学危害的归宿与迁移；（ii）长期土地施用对土壤微生物和化学性质的影响。已证明生物固体中病原体对人类健康造成的直接风险较低。气溶胶化病原体或微生物污染的地下水等间接暴露风险也较低。一项长期土地施用研究表明，微生物活性增强，且对土壤微生物群落没有不良毒性影响。长期土地施用还增加了土壤中的大量养分，包括碳、氮，尤其是磷。事实上，应注意避免高磷土壤污染地表水。由于生物固体中的金属含量低且土壤pH值高，在20年的土地施用期内，土壤中有效金属浓度一直较低。由于生物固体的盐分含量低且棉花灌溉率超过耗水率，未检测到土壤盐分增加。基于这些研究，我们的结论是，长期施用B类生物固体是可持续的。
