Uso de coagulantes naturais na clarificação da água como alternativa ao sulfato de alumínio

Abstract

The water is essential for life on the planet, so that safe human consumption is possible, it must undergo a treatment process. In conventional water treatment plants, the water clarification process is carried out using chemical coagulants such as aluminum sulfate. There are some studies that associate the use of this coagulant with the onset of neurological diseases such as Alzheimer's due to the residual aluminum present after treatment. Therefore, there are studies on alternative coagulants to aluminum sulfate. The objective of this work is to present an evaluation of the clarification process between natural coagulants based on moringa oleifera and tannin-based coagulant, Tanfloc SL, with aluminum sulfate used in conventional water treatment in the municipality of Caçapava do Sul. For this, the color and turbidity removal efficiencies of the coagulants were verified considering the same process used for the treatment with aluminum sulfate and the characteristics of the municipal water. A bench test (jar test) was used to determine the optimal dosages for each coagulant. By the statistical analysis of the data, there were similarities in the performance of the coagulants aluminum sulfate and Tanfloc SL and a difference in the performance of the coagulant based on moringa oleifera. However, the efficiency of the coagulants for removing the color and turbidity parameters, according to the optimal dosages found, was above 80%. Therefore, the study showed positive results in the use of natural coagulants, but the cost-benefit ratio makes the application of these treatments impracticable when compared to the application of aluminum sulfate coagulant in the municipality's ETA.