In this study, acute toxicities of raw, physico-chemically pre-treated, ozonated and to Fenton's oxidation applied samples of textile effluents, including towel dyeing, printing and finishing and Organized Industrial Region (OIR) wastewater on activated sludge microorganisms using respiration inhibition test (ISO 8192), are presented. Chemical pre-treatment positively affected the biodegradability, and inhibition on activated sludge was considerably removed (>48% color and >75% COD). Ozonation and Fenton processes showed high color (>90%) and COD (>70%) removal performance on evaluated effluents. No inhibitory effect of ozonated and to Fenton's reagent applied samples on activated sludge mixture was found. In addition to toxicity, color and COD removal efficiencies of the applied processes, their associated operating costs were also determined in this paper.