Management of agricultural use of sewage sludge: case study of Parana state, Brazil

The agricultural use is an environmentally sustainable destination for sewage sludge because it promotes the recycling of nutrients and is beneficial to the cultivation of plants and physicochemical and biological soil characteristics. It is a worldwide consolidated alternative, which in Brazil is limited to a few states. Parana is one of the states where the sewage sludge has agriculture as a priority disposal. This study aimed to evaluate the management of the agricultural use of sewage sludge process in the state of Parana, Brazil, in the 2011-2013 period. There were analyzed 49 traceability reports, 337 agronomic projects and laboratory reports of 129 batches of sewage sludge. It was found that 107,416 t of sewage sludge hygienised by prolonged alkaline stabilization were applied on 5,529 ha of agricultural land in Parana, with the Curitiba Metropolitan Region (CMR) responsible for 54% of the destination. Although the state has a greater potential of agricultural areas for the application of sewage sludge, compared to CMR, the expansion of activity in the interior of Parana is still modest, with only 22% of the total of 81 management units licensed in the state destining the sludge for agricultural use in 2013.