Application of advanced oxidation processes for removal of polluting parameters from paracetamol-containing wastewater

Depending on the rapid increase in the world's population, medicinal drug consumption for the purpose of treatment and protection has also been increasing. Pharmaceuticals can not be completely eliminated in the body after being used and can not be treated by classical biological treatment methods. The fate of pharmaceuticals is not exactly known in the long term after reaching the aquatic environment. They must be removed before reaching the aquatic environment in order to avoid the potantial risks. In this study, Fenton and foto-Fenton oxidations have been applied to the real wastewater which is formed during the synthesis of paracetamol (an analgesic and antipyretic drug). Due to the difference between polluting parameters of the samples taken at different times, chemical quantities were calculated according to COD/H2O2 and Fe2+/H2O2 ratios and polluting parameter removal efficiencies were compared by the way of finding optimum chemical ratios in both oxidations. Optimum chemical ratios of Fenton oxidation was determined as ?1/1-1/70? (COD/H2O2-Fe2+/H2O2) and for this ratios, COD, BOD5, TOC, paracetamol, para-aminophenol and aniline removal efficiencies were found as 92.7%±0.628, 95.5%±0.123, 92.7%±0,107, 99.1%, 99.9% and 99.4%, respectively. As a result of the removal efficiency improving studies for the optimum chemical ratios, the best settling method and pH were found as centrifuge and 6, respectively. Change of polluting parameters during the reaction and their concentrations at different phases were also investigated. Optimum chemical ratios of photo-Fenton oxidation was determined as ?1/1.5-1/70? (COD/H2O2-Fe2+/H2O2) and for this ratios, COD, BOD5, TOC, paracetamol, para-aminophenol and aniline removal efficiencies were found as 91.2%, 89.4%, 90.6%, 97.3%, 95.4% and 99.8%, respectively. By the way of comparing chemical quantities and removal efficiencies, it has been seen that Fenton oxidation is better than photo-Fenton oxidation. Key words: paracetamol, Fenton oxidation, photo-Fenton oxidation, electrocoagulation, COD, TOC