Evaluation of the municipal solid wastes ash as a source of plant nutrients and pollutants

The ash of municipal solid waste (MSW) as a plant nutrient and environmental pollutant was evaluated. Some of solid wastes, fermented partially, were collected from Hail region, Kingdom of Saudi Arabia. Ash samples were collected from Al-Gassim region too. The fermented MSW, Hail region, was incinerated then the resulted ash was mixed with a sandy soil at rates of 0.0, 0.1, 0.2 and 0.3 %. Similar study was achieved in the presence of 1% of the MSW. One kilogram of the soil mixture was packed per plastic container then incubated for 39 d at a range of -20 to -10 KPa water potential measured with a tensiometer. The concentrations of plant nutrients (P, K, Fe, Cu, and Zn) and the polluting elements (Pb, and Cd) increased as the ash percentage increased. The presence of the municipal solid wastes raised the level of the studied nutrients and elements in the soil. The nutrients concentrations under 0.0 and 0.3 % ash levels differed significantly. Fortunately, the pollutants concentrations in the extracts of the treated soil usually were well below concentration standards set by USEPA for biosolids. The ash of the MSW Hail is recommended as a source of plant nutrients for the sandy soils used. 0.1 % of ash is recommended for enriching the sandy soil with copper and zinc nutrients