Treatment of high saline textile wastewater by activated sludge microorganisms

Textile wastewater is a combination of various chemicals and different types of dyes and has a salty nature. In this study, an SBR (sequencing batch reactor) was used to treat synthetic and real textile wastewaters in a 24 h cycle time. Remazol Brilliant Blue R, a reactive dye, was used as the model dye. Dye concentrations ranged from 125 mg/L to 500 mg/L, and TDS (total dissolved solids) concentrations ranged from 1000 mg/L to 10,000 mg/L in synthetic wastewaters. For the highest dye concentration (500 mg/L) with low TDS, an 80.71% COD removal efficiency was obtained; at a TDS concentration of 5000 mg/L, a 59.44% COD removal efficiency was obtained. When the TDS concentration of wastewater was raised to 10,000 mg/L, COD removal decreased to 14.92% and reductions in MLSS (mixed liquor suspended solids) and MLVSS (mixed liquor volatile suspended solids) concentrations were observed. According to the results, increasing the TDS concentration of wastewater up to 5000 mg/L did not affect COD removal efficiency of the activated sludge microorganisms in the treatment system.