Environmental Effects of Land Application of Digested Municipal Sewage Sludge.

摘要

Land application of municipal sewage sludge was studied as an alternative to other disposal methods and as a method to reuse beneficial constituents. A subsurface injector for sludge previously developed and tested,was used to apply the sludge from a 4.3million gallon per day rated wastewater treatment plant in Boulder,Colorado,to a 4.4hectare site. Potential environmental hazards involved with land application of sludge were evaluated. It was decided that the primary dangers were to the soil and groundwater in the form of pathogen,heavy metal,nutrient,and salt contaminants. The application site was equipped with groundwater monitoring wells and leachate vacuum extractors. Corn was grown on one sludge treated plot. Analyses of leachate,groundwater,soil,and corn tissue were made,and the data collected are presented. An attempt was made to make a mass balance of the potential contaminants through the soil environment.