Tratamento de efluente de frigorífico de suínos por coagulação/floculação

Abstract

The objective of this study was to evaluate the aplicability and efficiency of use of vegetable tannin based coagulante in the clarification of effluents after conventional treatment. The effluents for the coagulation / flocculation tests were collected at the exit of the facultative pond in a pigs' refrigerator, and the tests were performed in jar test. The working conditions were a stage of rapid mixing, with speed of 120 rpm and time of 2,5 min, a slow mixing step, with speed of 20 rpm and time of 20 min, and settling time of 20 min. The experiment was carried out in two stages. In the first step the dosage of 50 mg.L-1 And pH value 5 as optimum due to the turbidity removal. Dosages of coagulant ranging from 10-60 mg.L-1 of TANFLOC SGC, and six pH values ranging from 3-8. In the second stage, turbidity (TB) removals were evaluated 96,5%, UV254nm 80%, total coliforms (TC) 36,1% and thermotolerant (Term) 48,5%, total solids (TS) 1,7% and electrical conductivity (EC) which continued the same, in the optimal condition obtained in the first step. The effluent reached characteristics that allow to be released in water resources class II, To be used for flushing to toilets after chlorine treatment for the reduction of thermotolerant coliforms or to be used for irrigation. However, due to the significant value of the TC concentration, Term and EC, the potential of soil contamination should be evaluated.