Uso de estufa agrícola para secagem e higienização de lodo de esgoto. / Use of greenhouse to dry and hygienization of the sewage sludge.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2010

RESUMO

This research aimed at assessing the dry and hygienization in a greenhouse excess of the activated sludge generated in Wastewater Treatment Plants that treats domestic sewage, located in the Metropolitan Region of the Great Vitória, Espírito Santo, and from the results, estimate the area and the cost of investment required for installation from the greenhouse. The intention was to meet the standards defined for sludge Class A (375/2006 Resolution of Conama) which enable the use of the material in the agriculture. The greenhouse had coverage and coating side canvas translucent plastic to prevent the ingress of water and allow the penetration of solar radiation. The study was divided into two stages, i.e. first, there was an assessment of the aerobically digested sludge behavior and, with and without lime, and second, the sludge which was not sent to the digester, with and without lime. Each part was composed by three cycles (repetitions) with differentiated methodological procedures and time of duration approximately of 70 days in order to evaluate the best configuration for the optimization of the studied technique. The concentrations of inorganic substances in the utilized sludge in the research were already presented with much lower values in relation to the standards of Conama. The parameters of monitored agricultural interest show interesting values under an agricultural aspect. In relation to virus, the presented results were inconclusive. Therefore, they were not used in the final considerations in relation to the utilized process. In face of the obtained results, it is reasonable to state that among the tested methodological conditions, the best configuration for the use of agricultural greenhouse in the dry and hygienization of the sludge, meeting the standards for the sludge Class A (except virus) was: the time of dry approximately 36 days; form of sludge disposition with 10 cm height; revolving period of 3 times a week; sludge without the addition of lime. With this configuration, it is possible to obtain a biosolid with moisture of approximately 25% resulting in a very expressive decreasing of volume, around 76%. Estimates of the size and cost were also performed.

ASSUNTO(S)

secagem dry higienização lodo classe a greenhouse custo cost hygienization lodo de esgoto sewage sludge sludge class a estufa agrícola

Documentos Relacionados