Saline Wastewater Treatment By Halophile-Supplemented Activated Sludge Culture in an Aerated Rotating Biodisc Contactor

Abstract

Synthetic wastewater containing 0–10% salt (NaCl) was treated in a rotating biodisc unit operating in continuous mode. Salt tolerant, Halobacter halobium-supplemented activated sludge culture was used in order to alleviate salt inactivation effects. Effects of important process variables such as inclusion of Halobacter, A/Q ratio, COD loading rate, and salt concentration on the COD removal rate and efficiency were investigated. The system performance improved with increasing A/Q ratio; however, it decreased with increasing COD loading rate and salt content. The liquid phase was aerated in order to keep suspended cells active at feed COD concentrations of 5,000 mg l −1. A mathematical model was developed to describe the system behavior. Model parameters were determined by using the experimental data. Salt inhibition was found to be significant for salt contents larger then 3% NaCl.