Evaluation of the quality of sewage sludge when subjected to drying / cleaning cultivated in greenhouse

Abstract

The intent of this investigation was to evaluate the performance of a greenhouse in drying and higienization of the sludge produced in the Wastewater Treatment Plants by activated‐sludge processes and aerobicly digested. The intention was to obtain material with characteristics that makes its utilization in the agriculture in agreement to the standard established by Resolution 375/2006 of the Conama. Therefore, different methodological conditions were studied such as the form of disposing the sludge inside the greenhouse, the revolving period of the sludge and the condition of adding or not alkaline material in the sludge. The monitored parameters were TS, VS, pH, moisture, thermo tolerant coliform, salmonella sp., viable helminth ova and heavy metal. Based on the results obtained it was possible to confirm that the utilization of the greenhouse was satisfactory for the appraised conditions, producing a Class A material, in conformity to the standard used.