The proper management of communal sewage sludge is a priority aim in today’s environmental protection. Among the possible technologies one environmentally sustainable sludge treatment technology can be the vermicomposting of communal sewage sludge. Before the successful operational level vermicomposting is absolutely necessary to investigate
...the process of vermicomposting in laboratory controlled conditions. In our studies vermicomposting of communal sewage sludge was carried out by comparing two earthworm populations in laboratory. During 6-week experimental period the temperature (with soil thermometer) and the redox potential (with ORP portable device) were measured every other day. The weekly, measured, basis parameters were the compost visual appearance, color and smell, pH (H2O), dry matter content, organic matter content, EC (conductivity), from which the total salt content can be calculated, total nitrogen content, phosphorus content (P2O5), potassium content (K2O), calcium and magnesium content, humus content (H%), determining the humus quality according to Hargitai’s method and dehydrogenase enzyme activity. It can be concluded from the results that the vermicomposting of studied communal sewage sludge has started and keeps going. The basic physical and chemical parameters (e.g. temperature, humus quality and quantity) support the changes. The results of humus quality and quantity which are priority variables of agriculture use show average increasing despite the initial recession. The changes of the important chemical parameters (nitrogen, phosphorus, potassium) in nutrient management were developed favorably. In our presentation the previous laboratory results are described.