Coagulante Tanfloc SG como alternativa ao uso de coagulantes químicos no tratamento de água na ETA Cafezal

Abstract

The purpose of this study was to use the natural coagulant Tanfloc SG as an alternative to eliminate particles in the raw water of ETA Cafezal , located in the municipality of Londrina and partially responsible for this water supply by coagulation / flocculation / sedimentation compared to two chemical coagulants, aluminum sulfate and ferric chloride. This being the currently used on its ETA . Was simulated with the jar -test the same conditions of rapid mixing and flocculation used in ETA . The values of gradient in a mixture consisting of rapid mixing time 450 s-1 , and decays four 90 s -1 52 s -1 40 s -1 and ending with 30 s- 1. After the test was carried out as a comparative study to remove turbidity , color, and apparent pH change after 0, 10, 20 and 30 minutes of settling . A comparative analysis of total and suspended between the natural and ferric chloride coagulant solids was also performed . The waters in the study were collected days prior to testing and showed two distinct characteristics : one with low turbidity and apparent color , and other values with relatively high values for the two physical parameters of the water . In tests conducted with water in rainy conditions , only the concentration of 25mg / L of chemical coagulants were effective , whereas for the natural coagulant, besides the dosage of 25mg / L to 45 mg / L also showed good performance. For water with normal characteristics , with low values of color and turbidity , only the concentration of 10mg / L of ferric chloride showed good yield . For Tanfloc SG , beyond this dosage to 8mg / L also had a good performance . Certain characteristics were observed, as it was found that a reduction of suspended solids in the water under study does not necessarily indicate a reduction in total solids present in it. It was found that the natural coagulant showed a negligible change in pH parameter, a good situation because if you can avoid using chemical products for pH correction . It was observed that even larger flocs formed and are sedimented faster compared to those formed by two metal coagulants. The results of percentage removal and statistical analysis indicated a significant potential for Tanfloc SG when compared to the two chemicals because the same have also obtained values of the parameters analyzed within the maximum permitted by the Ordinance of the Ministry of Health Potability coagulants and therefore You can replace the ferric chloride in the respective ETA .