Details

Autor(en) / Beteiligte

• Khan, Wasi Z.
• Najeeb, Imad
• Tuiyebayeva, Madina
• Makhtayeva, Zhibeek

Titel

Refinery wastewater degradation with titanium dioxide, zinc oxide, and hydrogen peroxide in a photocatalytic reactor

Ist Teil von

• Process safety and environmental protection, 2015-03, Vol.94, p.479-486

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2015

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• •Titanium dioxide, zinc oxide, and TiO2/H2O2 are effective catalysts.•The maximum degradation achieved was 40.68% by using TiO2 at 35°C within 120min.•The lower pH helps the photcatalytic reactivity of the catalyst.•When TiO2 was combined with H2O2 the maximum degradation was about 25.35% at pH 4.2.•The results indicate that TiO2 is comparatively more effective than ZnO and H2O2. This paper presents the photo-catalytic degradation of real refinery wastewater from National Refinery Limited (NRL) in Karachi, Pakistan, using TiO2, ZnO, and H2O2. The pretreatment of the refinery effluent was carried out on site and pretreated samples were tested at 32–37°C in a stirrer bath reactor by using ultra-violet photo oxidation process. The degradation of wastewater was measured as a change in initial chemical oxygen demand (COD) and with time. Optimal conditions were obtained for catalyst type, and pH. The titanium dioxide proved to be very effective catalysts in photo-catalytic degradation of real refinery wastewater. The maximum degradation achieved was 40.68% by using TiO2 at 37°C and pH of 4, within 120min of irradiations. When TiO2 was combined with H2O2 the degradation decreased to 25.35%. A higher reaction rate was found for titanium dioxide. The results indicate that for real refinery wastewater, TiO2 is comparatively more effective than ZnO and H2O2. The experiments indicated that first-order kinetics can successfully describe the photo-catalytic reaction. The ANOVA results for the model showed satisfactory and reasonable adjustment of the second-order regression model with the experimental data. The ANOVA results also showed that pH is significant than reaction time and catalyst dosage of TiO2; and in case of ZnO, reaction time is significant than pH and catalyst dosage. This study proves that real refinery wastewater reacts differently than synthetic refinery wastewater, oil field produced water or oil water industrial effluent.