Degradation of polychlorinated biphenyls using UV/H2O2: Effects of initial oxidant and PCB concentrations

• Main Authors: Centeno, Carmela R., Estrellan, Carl Renan E., Abella, Leonila C., Maridable, Julius B., Gallardo, Susan M.
• Format: text
• Published: Animo Repository 2004
• Subjects: Polychlorinated biphenyls—Oxidation; Oxidation; Chemical Engineering
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/9176
• Institution: De La Salle University

In this study, the degradation of polychlorinated biphenyls (PCBs) using UV/H2O2 system was investigated. The effects of initial H2O and PCB concentrations were studied using batch tubular reactor equipped with a 254 nm low-pressure Hg lamp. Samples were withdrawn from the reactor at desired time intervals. The temperature and pH of the solution were continuously monitored. Initial H2O concentrations of 8.8mM, 17.64mM, 22.05mM, 24.71mM, 26.47mM abd 35.29mM were used to determine the optimum oxidant concentration while initial PCB concentrations of 40ppm, 20ppm, 10ppm, 5ppm and 1 ppm were employed to study the effect of this parameter on PCB degradation.Results show that there is an optimum H2O2 concentration that maybe used beyond which no significant increase in the degree of degradation was achieved. The highest PCB degradation efficiencies of85.69% after 60 minutes and 94% after 300minutes were obtained at a peroxide concentration of 22.05mM and PCB concentration of about 40 ppm. The initial concentration of PCBs at the given optimum peroxide concentration obtained also proved to have a significant effect on the degradation of the compound. Results indicate that, wth the initial PCB concentrations employed, PCB photodegadation increases as the initial concentration increases.The use of UV/H2O2 for PCB degradation seems very promising in the treatment of wastewater containing PCBs. The results of this study are highly significant in performing a kinetic analysis on PCB degradation.