Integral treatment of wool scouring effluents - 1. Anaerobic digestion - 2. Posttreatment separation by coagulation flocculation

The anaerobic digestion of woolscouring wastewater (First Part) and a postr eatment separation by coagulation-flocculation (Second Part) are presented. First Part: A laboratory anaerobic baffled reactor (ABR) was operated with woolscouring effluent. The processed organic load was 5.1 Kg COD/m(3) d, CO D and grease removal were 53% and 66% respectively A 300 m(3) ABR was built and operated during two years based on the previous laboratory results. CO D removal was between 45% to 18% with organic load of 3 to 20 Kg COD/m(3)d. The detergent is partially degraded loosing its emulsifying properties. Second Part: The dosage of coagulants and flocculants was optimized irt a c ontinuous coagulation-flocculation device with high turbulent regime and hy draulic residence time lower than 120 seconds. Efficiencies of suspended so lids removal of 95% were obtained. The final effluent COD was lower than 15 00 mg/L. The global COD efficiency of the wastewater treatment is higher th an 98 %.