Treatment of a Pharmaceutical Industrial Effluent by a Hybrid Process of Advanced Oxidation and Adsorption

[Image: see text] In the present study, a combined approach of ozone-based advanced oxidation and adsorption by activated char was employed for the treatment of a pharmaceutical industrial effluent. Ozone is a selective oxidant, but the addition of H(2)O(2) generated in situ hydroxyl radicals, which is a non-selective stronger oxidant than ozone. The effluent obtained from the pharmaceutical industry mainly contained anti-cancer drugs, anti-psychotic drugs, and some pain killers. The peroxone process had 75–88.5% chemical oxygen demand (COD) reduction efficiency at pH 5–11 in 3 h. Adsorption by activated char further reduced the COD to 85.4–92.7% for pH 5–11 in 2.5 h. All other water quality parameters were significantly decreased (>73% removal) during ozonation. The primary operational parameters (system pH and H(2)O(2) concentration) were also varied, and their effects were analyzed. The pseudo-first-order rate constants for ozonation were calculated, and they were found to be in the range of 1.42 × 10(–4) to 3.35 × 10(–4) s(–1) for pH 5–11. The kinetic parameters for adsorption were calculated for the pseudo-first-order, pseudo-second-order, and Elovich models. The fit of the pseudo-first-order kinetic model to the experimental data was the best.