Evaluation of Efficiency of Russian Knapweed Flower Powder in Removal of Reactive Blue 19 from Synthetic Textile Wastewater

Colors are complex structural materials، which enter into the environment due to finishing processes of textiles such as dyeing and printing. Reactive Blue 19 dye is used widely in the textile industry within the country. Therefore، we investigated the efficiency of the Russian knapweed flower powder as natural adsorbent in the removal of Reactive Blue 19 dye from synthetic textile wastewater. This experimental study was performed in laboratory scale. In this study، the effect of adsorbent dose، contact time، pH and different dye concentrations on efficiency of adsorption process has been studied and finally، correspondence rate of data to Langmuir and Freundlich isotherms and pseudo-first-order and pseudo-second-order adsorption kinetics were determined. For analysis of the data liner regression and R2 parameter and design of curves were used. According to the obtained results، increasing of adsorbent dose from 0. 2 to 0. 6 gr/100ml in concentrations of 10 and 25 mg/l RB19 led to an increase in the of removal efficiency from 77% to 88% and from 72% to 82%. Adsorption capacity by increasing of initial pH from 4 to 10 for concentrations of 10 and 25 mg/l has increased from 0. 28 to 1. 64 mg/g and from 2. 3 to 3. 945 mg/g، respectively. Obtained results showed that with the increase of contact time، removal efficiency increased and with increasing of initial dye concentration، removal efficiency decreased. According the to obtained results، Langmuir isotherm was in good concordance with the 1`data. The model of pseudo-second-order kinetic has shown better agreement with the experimental data. The results indicated the suitability of Russian knapweed flower powder as natural adsorbent for color removal.