Using ash from incineration of municipal sewage sludge to fertilize Virginia Fanpetals

: The purpose of this paper was to determine the effect of ash from a sewage sludge incinerating facility on yields and mineral composition of Virginia fanpetals, and on the content of heavy metals in soil. The study was based on a pot experiment in which ash obtained from sewage sludge incineration at the Lyna Wastewater Treatment Plant was used as a substitute of mineral fertilizers. The dominant fertilizing ingredients found in the analyzed ash were phosphorus and calcium. The content of cadmium and lead was lower than the allowable concentrations of these metals in mineral fertilizers. Ash from incinerated sewage sludge did not have any substantial effect on the soil content of the mobile forms of cadmium, copper, lead and chromium. With respect to three metals, namely nickel, zinc and manganese, the medium and high doses of ash raised significantly their concentrations in soil. The rate of ash had no influence on the content of sodium and magnesium in the plants but when the highest dose of ash had been applied, the concentration of calcium in plants rose significantly. Ash modified the content of heavy metals in the plant material only very slightly.