Removal of phenol from wastewater using tea waste and optimization of conditions using response surface methodology

In the current work the capability of adsorbent prepared from tea waste to remove phenol from the wastewater was investigated. The adsorbent was prepared by treating with sulphuric acid to enhance the properties. The characterization of the adsorbent was done by measuring the surface area, pore volume and particle size. The influence of three operating parameters like pH, concentration and dosage on the percent removal was investigated using response surface methodology (RSM). From the central composite design, a quadratic model was developed with a correlation coefficient of 0.9509. The model was helpful in correlating the three experimental variables to the percent removal as the response. Equilibrium isotherms for phenol adsorption were investigated using Freundlich, Langmuir and Temkin isotherm models. The kinetic studies were carried out at the optimum conditions and it was observed that the data were fitting pseudo-second order model. The equilibrium data obeyed Langmuir model showing the monolayer adsorption capacity of 5.80 mg/g in the concentration range of 40-180 mg/L.