Batch treatment of saline wastewater by Halanaerobium lacusrosei in an anaerobic packed bed reactor

BACKGROUND: This study considers batch treatment of saline wastewater in an upflow anaerobic packed bed reactor by salt tolerant anaerobic organisms Halanaerobium lacusrosei . RESULTS: The effects of initial chemical oxygen demand (COD) concentration (COD 0 = 1880–9570 mg L −1 ), salt concentration ([NaCl] = 30–100 g L −1 ) and liquid upflow velocity ( V up = 1.0–8.5 m h −1 ) on COD removal from salt (NaCl)‐containing synthetic wastewater were investigated. The results indicated that initial COD concentration significantly affects the effluent COD concentration and removal efficiency. COD removal was around 87% at about COD 0 = 1880 mg L −1 , and efficiency decreased to 43% on increasing COD 0 to 9570 mg L −1 at 20 g L −1 salt concentration. COD removal was in the range 50–60% for [NaCl] = 30–60 g L −1 at COD 0 = 5200 ± .100 mg L −1 . However, removal efficiency dropped to 10% when salt concentration was increased to 100 g L −1 . Increasing liquid upflow velocity from V up = 1.0 m h −1 to 8.5 m h −1 provided a substantial improvement in COD removal. COD concentration decreased from 4343 mg L −1 to 321 mg L −1 at V up = 8.5 m h −1 , resulting in over 92% COD removal at 30 g L −1 salt‐containing synthetic wastewater. CONCLUSION: The experimental results showed that anaerobic treatment of saline wastewater is possible and could result in efficient COD removal by the utilization of halophilic anaerobic bacteria. Copyright © 2008 Society of Chemical Industry