Composting of sugarcane trash used as filtering material for swine wastewater

摘要

The modern swine production under confined conditions due to accumulation of dejects in small areas, generates large volumes of wastewater of high potential pollutant for the soil, the air and the water, since it is rich effluent in solids in suspension and dissolved organic nutritients (nitrogen and phosphorus, among others), pathogenic agents, heavy metals and several salts. In the present work the composting of organic residue (sugarcane trash) used as filtering material for swine wastewater was evaluated immediately after the material lost its filtering capacity and was discarded from the column. The results led to the conclusion that the sugarcane trash corresponds to fertilizer obtained by biochemical, natural and controlled processes from mixture of residues of vegetable or animal origin, having one or more plant nutrients.The evaluation of chemical composition of the matured compost showed that the sugarcane trash plus swine residue presented total concentration of heavy metals that can be considered safe from the crop fertilization point of view, provided that the criterion of maximum rate of accumulative application is observed.