PHYSICOCHEMICAL TREATMENT OF THE EFFLUENTS OF THE WOOL WASHING PROCESS IN A TEXTILE INDUSTRY OR AREQUIPA

Abstract

The objective of this study was to evaluate the physicochemical treatment of wool washing effluents from a textile industry in the city of Arequipa in order to comply with the Maximum Admissible Values (VMA), using 40% ferric trichloride as coagulant and 0,1% MT-FLOC 4299 polymer flocculant. The effluent was physically and chemically characterized at the beginning and at the end of the treatment, measuring pH, temperature, Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), total suspended solids (TSS), oils and fats, sulfates, ilosulphides, ammoniacal nitrogen, total cyanide, hexavalent chromium and turbidity. To determine the optimal doses of coagulant and flocculent, three treatments were done using a jug set at 50, 200 and 40 rpm. The sedimentation time of the floc was 10 minutes. The initial turbidity ranges oscillated between 200 and 800 NTU, obtaining a removal of 89 % in relation to the average turbidity of 526.96 NTU. The best dose applied to the effluent was 200 mg/L of ferric trichloride and 0,8 mg/L of the cationic polymer flocculent MTFLOC 4299. The contaminant removal parameters were: 84,97 % oils and fats; 82,55 % Biochemical Oxygen Demand; 79,36 % Chemical Oxygen Demand; 99,60 % suspended total solids; 96,67 % settleable solids and 75,65% total cyanide, thus complying with the Peruvian Regulations, so it is feasible to apply the treatment on a larger scale.