Post-treatment of effluents from anaerobic reactor treating domestic sewage by dissolved-air flotation

摘要

This paper presents the results of a study performed with a lab-scale dissolved-air flotation (LSDAF) unit fed with previously coagulated effluent from a pilot scale up-flow anaerobic sludge blanket (UASB) reactor treating domestic sewage. Physical operational conditions for coagulation (rapid mix) and flocculation/flotation were maintained constant. Chemical (FeCl_3) dosages ranged from 30 to 110 mg.1~(-1). The effect of pH was also verified in the range of 5.1 to 7.6 for each dosage. Best results were achieved for 65 mg.1~(-1) of FeCl_3 and ph values between 5.3 and 6.1. For these conditions, the removal efficiencies obtained in the LSDAF unit were: between 87