Możliwości nieprzemysłowego wykorzystania odpadów z uwzględnieniem zasad obowiązujących w ochronie środowiska

The aim of this work was to estimate mobility of pollutants contained in ashsludge granulates, expressed by their possibilities of elution by water and by estimating their potential danger to the environment. Materials used in experimental research (one stage leaching tests) was ash-sludge granulates made of two different kinds of waste: fly ashes from brown coal (30%) from 'Bełchatów' Powerplant and communal sewage sludge (70%) from municipal sewage treatment plant in Zabrze (southern Poland). However sewage sludge are an alternative to organic fertilizers (e.g. manure) and nitrogen and phosphorus content is relatively high but potassium concentrations are much less. Tested sewage sludge were modified by various potassium salts, which would improve their fertilizing abilities because potassium is easy-leaching element during sewage treatment. In first part of sewages KCl and in second K2SO4 were used both in load 344 g/kg d.m. Blank tests were carried on unmodified material. One stage leaching test were carried and equilibrium was reached after 24 hours. Water extracts (eluates) were analyzed for presence of nitrogen group compounds, phosphorus, chlorides, sulphates, magnesium, calcium and heavy metals. Also loads of particular compounds were calculated. On the basis of research (leaching test) there has been calculated a load of the pollution that were being washed out in mg/kg dry mass of used granulates. Eluates obtained in one-stage leaching tests had alkaline pH and high EC value which rise with potassium concentrations. In eluates from tested materials some parameters (e.g. ammonium, nitrites, COD, sulphates and potassium) exceed polish limits for sewages discharged to waters and grounds. Especially high were chlorides concentrations (10 times to high) due to KCl content. The highest heavy metals concentrations were observed in eluates from granulates modified by K2SO4 due to lower pH value in comparison to unmodified material. In next step in this researches will be to find optimal balance between fly ash and sewage sludge and use compounds for pH corrections.