COMPARAÇÃO ENTRE O COAGULANTE NATURAL TANINO E OS COAGULANTES INORGÂNICOS PAC E CLORETO FÉRRICO PARA O TRATAMENTO DE ÁGUAS RESIDUAIS DA INDÚSTRIA DE RECICLAGEM DE PLÁSTICOS

Abstract

The present research sought to carry out the treatment of an effluent from the plastic washing processes, present in a recycling industry. For this purpose, the performance of the natural tannin coagulant in relation to the inorganic coagulants of polyaluminium chloride (PAC) and ferric chloride was analyzed. The parameters studied were related to the removal of apparent color, turbidity and COD. The bench scale treatment consisted of the physical-chemical processes of coagulation, flocculation and sedimentation, and the determination of the amount of tests required and the processing of the results obtained were carried out using the Statistica software. The test variables were the coagulant dosages and the coagulation pH, and after the discovery of the ideal treatment, the performance of the tannin coagulant in relation to the removal of phosphorus, nitrogen, suspended solids and total solids, as well as changes in conductivity and alkalinity were also verified. All coagulants reached results of removing turbidity, apparent color and COD above 97%, with emphasis on tannin, which in addition to exceeding 99%, facilitates the disposal of sludge, as it is a biodegradable coagulant.