Effects on Soils and Vegetation of Plant Nutrients and Heavy Metals from Wastewater-Treatment-Plant Sludges Disposed on Land

摘要

Sludges and effluents from wastewater-treatment-plants in West Virginia cities were analyzed chemically for fourteen elements. By greenhouse and field applications to corn and soybean crops, sludges were evaluated for effectiveness in providing plant nutrients and in introducing heavy metals into the food chain. Plant nutrients, especially nitrogen and phosphorus, occurred in amounts beneficial to plant growth. Toxic manganese levels in soils were reduced by sludge application. Use of lime and phosphorus fertilizer retarded heavy-metal absorption by the crop plants. Nutrients and heavy metals were restricted to upper soil horizons. Cadmium is the only one of these elements that could cause alarm by accumulating to toxic levels in plants grown on sludge-amended soils.