scholarly journals Removal of COD and SO42− from Oil Refinery Wastewater Using a Photo-Catalytic System—Comparing TiO2 and Zeolite Efficiencies

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 214 ◽  
Author(s):  
Emmanuel K. Tetteh ◽  
Elorm Obotey Ezugbe ◽  
Sudesh Rathilal ◽  
Dennis Asante-Sackey

Advanced oxidation processes (AOPs) have many prospects in water and wastewater treatment. In recent years, AOPs are gaining attention as having potentials for the removal of different ranges of contaminants from industrial wastewater towards water reclamation. In this study, the treatability efficiencies of two photo-catalysts (TiO2 and zeolite) were compared on the basis of the removal of chemical oxygen demand (COD) and SO42− from oil refinery wastewater (ORW) using photo-catalytic system. The effects of three operating parameters: catalyst dosage (0.5–1.5 g/L), reaction time (15–45 min), mixing rate (30–90 rpm) and their interactive effects on the removal of the aforementioned contaminants were studied using the Box–Behnken design (BBD) of response surface methodology (RSM). Statistical models were developed and used to optimize the operating conditions. An 18 W UV light was incident on the system to excite the catalysts to trigger a reaction that led to the degradation and subsequent removal of contaminants. The results obtained showed that for almost the same desirability (92% for zeolite and 91% for TiO2), TiO2 exhibited more efficiency in terms of mixing rate and reaction time requirements. At the 95% confidence level, the model’s predicted results were in good agreement with experimental data obtained.

Author(s):  
Muzher Al doury ◽  
Hadeel Al samerrai

The use of conventional flocculants such as Aluminum sulphate (Alum) alone to treat the wastewater may be insufficient to get the required turbidity, suspended solids removal as well as it requires relatively a long residence time. Magnetic flocculation is one of the used techniques for increase the efficiency of the turbidity removal. In the present study, three sets of experiments are carried out in order to investigate the possibility of increasing the suspended solid removal efficiency from Al Doura oil refinery wastewater using iron oxide (Fe3O4), Nickel (Ni), and Cobalt (Co) ferromagnetic powders with alum. The following operating conditions namely, pH, alum dose, ferromagnetic powder dose, and initial turbidity are studied. The results revealed that an improvement in turbidity removal efficiency is satisfied, as well as, a reasonable reduction in the sedimentation period is achieved. The highest turbidity removal is 99.88% that obtained for 122NTU sample for alum dose 120 mg/L+ Nickel dose of 80mg/L and pH of 6.5.


2018 ◽  
Vol 8 (3) ◽  
pp. 438 ◽  
Author(s):  
Hasna Addi ◽  
Francisco Mateo-Ramírez ◽  
Víctor Ortiz-Martínez ◽  
María Salar-García ◽  
Francisco Hernández-Fernández ◽  
...  

1986 ◽  
Vol 18 (9) ◽  
pp. 105-114 ◽  
Author(s):  
D. Misković ◽  
B. Dalmacija ◽  
Ž Živanov ◽  
E. Karlović ◽  
Z. Hain ◽  
...  

The objective of the present investigation was a high level of purification of the wastewater from an oil refinery achieved by using some improved methods yielding an effluent suitable for recycling into the process. All the investigations were carried out on a continuous laboratory pilot system consisting of the following units: dissolved air flotation (DAF), sedimentation, double-stage microbiological reactor, and adsorption columns filled with granular biologically activated carbon (GBAC). A high degree of COD reduction close to 100% (precisely, 99.95 %), as well as removal of nitrogen compounds of 72% was achieved during a relatively short retention time within the range of 15-16.5 hrs. The DAF technique combined with gravitational separation was used to achieve the recovery of free oil matter up to 98%, without any preliminary conditioning. After the sedimentation of coagulated and flocculated dispersed oils, the microbiological oxidation of dissolved matter was accomplished by using two kinds of activated sludge for easy and hard degradable organics. Using the continuously bioregenerating GBAC, an effluent having a lowered COD value to about 9 was obtained. At the same time, the denitrification process took place. According to the obtained results the treated oil refinery wastewater can be recycled into the process, or discharged into a water recipient of a low self-purifying capacity.


2018 ◽  
Vol 78 (5) ◽  
pp. 1159-1167 ◽  
Author(s):  
Behnam Heidari ◽  
Mohsen Soleimani ◽  
Nourollah Mirghaffari

Abstract The Fenton process is a useful and inexpensive type of advanced oxidation process for industrial wastewater treatment. This study was performed with the aim of using the steel slag as a catalyst in the heterogeneous Fenton process in order to reduce the chemical oxygen demand (COD) of oil refinery wastewater. The effects of various parameters including the reaction time (0.5, 1.0, 2.0, 3.0 and 4.0 h), pH (2.0, 3.0, 4.0, 5.0, 6.0 and 7.0), the concentration of steel slag (12.5, 25.0 and 37.5 g/L), and H2O2 concentration (100, 250, 400 and 500 mg/L) on the Fenton process were investigated. Furthermore, the effect of microwave irradiation on the process efficiency was studied by considering the optimum conditions of the mentioned parameters. The results showed that using 25.0 g/L of steel slag and 250 mg/L H2O2, at pH = 3.0, could reduce COD by up to 64% after 2.0 h. Also, microwave irradiation decreased the time of the process from 120 min to 25 min in the optimum conditions, but it consumed a high amount of energy. It could be concluded that steel slags had a high potential in the treatment of oil refinery wastewater through the Fenton process.


2019 ◽  
Vol 28 ◽  
pp. 115-122 ◽  
Author(s):  
Mojtaba Ahmadi ◽  
Khaled Zoroufchi Benis ◽  
Mehrdad Faraji ◽  
Mohammad Shakerkhatibi ◽  
Atefeh Aliashrafi

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