Statistical analysis of congo red dye removal using sawdust activated carbon

In the present study, an adsorbent was prepared from Ben Teak sawdust by chemically treating and carbonizing with phosphoric acid. Using Design Experts software, 2 level factorial studies and Response surface methodology studies using Box-Benkhen design model were carried out and a relationship between Qe and pH, temperature, concentration of dye, amount of adsorbent, agitation speed were derived for Congo red- Saw Dust Carbon(SDC). Maximum Congo-red removal of 96.764 % and adsorption capacity of 149.507 mg/g was found at pH 2, 30 °C, 125 rpm, 150 mg/L and 1gram/L of reaction mixture for an optimum contact time of 2.5 hours. Adsorption isotherm obtained fitted well into both Freundlich and Langmuir equation but Freundlich isotherm fits better with 1/n ranging from 0.4944 to 0.5894 and R² ranging from 0.92333 to 0.952. The q_max from Langmuir isotherm was established to be 209.7 mg/g.