Sistema de confinamento de resíduos empregando geotêxteis comparados a leito de drenagem para desaguamento de lodo de estação de tratamento de água

Abstract

In the anthropocen era, a growing concern about environmental issues emerges; one of these is impacts associated with the final disposal of waste generated in Water Treatment Plants (WTP). The article evaluates the effectiveness of geotextile closed systems, also referred to as waste containment systems (WCS) in relation to drainage beds, both considered systems usually used in the disposal of wastes generated in WTP. In the tests carried out, both the SCR prototype and the drainage bed were used as waste only chemically conditioned WTP sludge. The choice of five different polymeric conditioning agents, four cationic and one anionic, was performed by means of a cone test, in which the concentration and preliminary determination of the dosage to be used were evaluated. The prototypes and their replicates received four refills of 10 L of sludge every thirty minutes and were then exposed to the weathering for 420 hours. During the experiment, the same boundary conditions were maintained, with the fixation of controllable variables and weighting of the variables responses of the experimental campaigns: percolated volume and turbidity, as well as time efficiency of sludge dewatering/desiccation process. The results were promising. At the begin, both systems presented similar values of turbidity and volume of percolated;however, when exposed in the field, due to weathering, mainly precipitation, at the end of 420 hours the solids content was initially of 7.4% to 66.4% in the WSC and 32.4% in the drainage bed.