HALOPHILIC BIOLOGICAL TREATMENT OF TANNERY SOAK LIQUOR IN A SEQUENCING BATCH REACTOR

Feasibility of biological treatment of hypersaline tannery wastewater rich in organic matter and total dissolved solids. The soak liquor was treated during 300 days in an aerobic SBR seeded with halophilic bacteria and the performance was evaluated under various operating conditions with changes in hydraulic retention time (HRT), organic loading rate and salt concentration. Proper removal of organic matter once the acclimatation of the microorganisms was achieved. Low biodegradability of the liquor containing high nitrogen content but fairly low phosphorous content. Optimal removal efficiencies on COD and suspended solids could be reached with 5 days HRT.