Análise da utilização de policloreto de alumínio (PAC) e sulfato de alumínio na eliminação de turbidez de água de abastecimento

Abstract

This research aims to evaluate the turbidity removal of the coagulants Aluminum Sulfate and PAC, in a conventional drinking-water treatment plant. For this proposal, were evaluated the data of raw and treated water, which was collected in the supply company’s laboratory, plus a monitoring, in a period of 2 months, of the water’s remaining turbidity. The results showed that both coagulants are effective, when used correctly, achieving a turbidity removal of 96% and 99% for the aluminum sulfate and PAC, respectively. However, analyzing the residual turbidity, for a longer period, it was observed that the treated water’s quality ranged considerably and, occasionally, overstepped the legal limit (≤ 1,00NT). It’s believed that this os due by some drinking-water treatment operational problems, specially in the hidraulic mixing, coagulantion, floculation and filters, raw water’s variation of quality and input flow, which requires a new coagulante dose, besides de presence o fair in the systems in a few moments.It’s concluded that the coagulante Works correctly when administered correctly. However, some operational issues may compromisse the treated water’s quality.