TREATMENT OF 4-CARBOXYBENZALDEHYDE BEARING WASTEWATER

Abstract

4-carboxybenzaldehyde is a toxic chemical comes into existence during the manufacturing of Terephthalic acid (TA) as a byproduct in major amount. In the present study, RHA as an adsorbent was used for the removal of 4-carboxybenzaldehyde from aqueous solution, surface methodology was employed for this purpose. Experiments were carried out according to Box-Behnken surface statistical design with four input parameters namely adsorbent dose (w: 5-20 g/l), contact time (t: 2-6 h), temperature (T: 15-45 °C) and pH (pH: 2-8). Initial 4- carboxybenzaldehyde concentration (Co=100 mg/1) was taken as a fixed input parameter. Regression analysis showed good fit of the experimental data to the second-order polynomial model with coefficient of determination (R2) value of 0.9766 and Fisher F-value of 41.78. Optimization of w (5 g/l), t (4 h), T (15 °C) and pH (2.5) gave a maximum of 89% 4- carboxybenzaldehyde removal by RHA. Langmuir isotherm was suitable for RHA-p-CBA system. The pseudo-second-order kinetics represents the equilibrium data well