Abstract:
Presence of salinity 8 to 20 g/L of chlorides can cause osmotic stress or inhibit the reaction pathways in the organic degradation process. It results in a significant decrease in biological treatment efficiency or biodegradation kinetics. Research is carried out using glucose-glutamic acid and domestic wastewater to evaluate the amendment of chlorides on biodegradation of sewage at 20°C. The findings confirm the hypothesis of biological oxidation rate "k" has higher value under presence of up to 6 g/L of chloride concentrations, compared to that of fresh water medium, being almost 25% higher at certain salt concentrations. It was also noticed that improvement of K value was more pronounced during the first 3 days even when the 5-day BOD showed an inhibition, a fact that needs further analysis. These values are of significance for co-treatment of sewage and industrial wastewater containing high salt concentrations. A morphological classification of the bacterial colonies showed that the number of colonies per mL of the sewage sample increased significantly on increasing the salt concentration from zero to 6 mg/L for E. coli, Enterobacter, Klebseilla, Serratia, Citrobacter, Salmonella, Shigella,