Adsorption of Reactive Red 198 Dye on TiO2 Nano-particle from Synthetic Wastewater

Dyes are one of the most important existing pollutants in textile industrial wastewater. They are often toxic, carcinogenic, teratogenic, and non-biodegredable. Reactive red 198 dye is one of the azo dyes that is currently used in the textile industry. This study was conducted with the aim of investigating on reactive red 198 dye absorption process titanium dioxide nanoparticles from synthetic textile wastewater. This applicable research was performed in a batch reactor on synthetic wastewater with dye concentrations of 100, 150 and 200 mg/L and the effects of parameters such as concentrations of initial dye and TiO2 nanoparticles, time, and pHs on dye absorption efficiency were investigated. The dye concentrations were measured via spectrophotometer (518 nm wavelength). The RR 198 absorption capacity rates were 92.5, 70, and 37.5 mg/g respectively at pH of 4, 7 and 10 for the initial dye concentration of 100 mg/L and 0.4 g/L absorbent mass at 180 minute. Also dye absorption rates were 51.8, 56.1, and 61.4 mg/g on absorbent respectively for 100, 150, and 200 mg/l dye concentration, at pH of 4, 1 g/L absorbent mass, and 180 minutes time and the studied dye absorption isotherm was fitted Langmuir model (R2=0.98) which was 38.46mg/g for maximum adsorption. The results of absorption studies showed that reactive red 198 absorption/removal rates would increase with increasing the primary dye concentration, reaction time, absorbent mass, and decreasing pH. On the basis of the results, titanium dioxide nanoparticles can absorb reactive red 198 dye appropriately and efficiency of the process is higher in acidic pH. Regarding to TiO2 application as a photocatalyst in environmental pollutant removal, more pollutant absorption on nanoparticles in acidic condition increases photocatalyst process efficiency