Soil microbial activity under wastewater treatment plant sludge doses from an industrial landfill

The final disposal of industrial solid waste is a major environmental problem. Disposal of organic wastes in soils can be recommended as corrective and fertilizer. The objective of this study was to evaluate the effect of different doses of wastewater treatment plant sludge (WWTP) from an industrial landfill on soils based in microbial activity measured by carbon mineralization. The experiment was developed in respirometric flasks, analyzing carbon mineralization in three soils with five doses of sludge during 91 days of incubation. Application of sewage sludge with 2 Mg ha(-1) caused minor impacts on soil microorganisms, without statistical differences to the control treatment. Amounts of mineralized carbon increased with the time course due to the addition of sludge, proportional to the doses of sludge. Microbial activity increased with the application of WWTP sludge doses of industrial landfill, with mineralization proportional to the increase in carbon added doses.