The inhibition effect of ozonation in textile wastewater

Abstract

The textile industry effluent includes toxic, mutagenic, carcinogenic compounds. Color containing substances are one of the most important effluents among these compounds. These substances should be treated and for the treatment of these substances, biological wastewater treatment processes are frequently preferred. However, biological wastewater treatment processes might not be adequate, therefore, advanced treatment processes could be applied for textile effluent to meet the discharge limits. One of the often-used advanced treatment processes is ozonation. Ozone is a disinfectant and a powerful oxidant The aim of this study is to show the effects, which include decolorization and inhibition effects, of ozonation on real textile wastewater after anaerobic treatment. For evaluating of ozonation efficiency DOC, alkalinity, pH, ORP and color were measured. The change of color was measured at 436 nm, 525 nm and 620 nm wavelengths. In conclusion, with 10 minutes of ozone contact time, color and DOC are removed by 80% and 65%, respectively. The inhibition tests indicate that the effluents should be considered slightly toxic with 10 min ozonation time. Keywords: ozonation, textile wastewater, decolorization, inhibition effect.