Study on coagulation and flocculation for treating effluents of textile industry - doi: 10.4025/actascitechnol.v35i1.11685

Resumo

This study investigated the optimization of time of coagulation, flocculation, and sedimentation of the chemical coagulant, aluminum sulfate and natural coagulant, Tannin. It was performed an economic analysis of the process, checked the removal efficiency of color, turbidity, COD, and treatment characterization using metals, BOD₅, and total solids. The tests were conducted in Jar Test, using different mixing and sedimentation times. The time required to provide the rapid and slow mixing were 2 and 20 minutes, respectively, for the investigated coagulants, with optimum concentration of
400 mg L^-1 for Tannin and 600 mg L^-1 for Aluminum Sulfate. For the analyzed parameters, the percentage of removal, according to the best optimization test were 93.12, 99.06 and 99.29% for COD, color, and turbidity, respectively, using the coagulant aluminum sulfate, and 94.81, 99.17 and 99.65% for COD, color and turbidity, respectively, using the coagulant Tannin.