The Problem

This sewer if duly treated would produce 25,000 the 35,000 m3 of primary silt (with 3 7% of solids) and of 150.000 the 200,000 m3 of secondary silt (with 0,5 20% of solids) per day. This problem still more will be aggravated with the perspective of inclusion of more 70 million urban inhabitants in the nets of collection in next the fifteen years (ANDREOLI et al., 1998). Exactly the systems of implanted treatment of sewer already are many operated times improperly, what it diminishes its efficiency, characterizing themselves as the great wastefulness of public resources that had been invested with the sacrifice of the population and they do not bring the waited benefits. In such a way existence of the problem of the sewer silt is an advance, therefore it means that the first step in direction the solution of the problem of the pollution already was given (ANDREOLI et al., 1998). The correct treatment and disposal of the sewer silt must be part of all the urban and industrial effluent program of treatment of, so that the objectives of the sanitation effectively are reached.

The costs of these operations can reach 60% of the operational costs of these stations and, therefore & cannot be neglected (WEBER; SHAMES, 1984). During years, however, the projects of the treatment stations practically ignored the destination of the biosslidos ones. (ANDREOLI et al., 1998). The problem of the management of these residues, great complexity technique and with significant costs in the operational procedures passed to be managed in situation of crisis for the operational areas, that initially store this material in contiguous areas the ETEs and when the amount goes if augmenting, launches hand of all the half ones stops if to exempt emergencialmente of the generated residues. In such a way it is not uncommon to find silt stored in precarious conditions, the simple distribution for agriculturists without security criteria, arriving until the o nonsense technician of its simple launching in courses d? water.