Performance Analysis of Various Advanced Oxidation Processes on COD Removal from Raw Petroleum Refinery Effluent

Objectives : This comparative study investigated various methods of advanced oxidation processes (AOPs) that were separately conducted for treating raw petroleum refinery effluent regarding chemical oxygen demand (COD) removal.Methods : Fenton, photo-Fenton, TiO2, ZnO, TiO2/Ultra violet (UV), and ZnO/UV were performed individually for measuring the effect of light irradiation, treatment time, pH, catalysts dosage, and light source on the profile of COD values.Results and Discussion : The experimental data of this work showed that the dependency on the light exposure in heterogeneous photo-catalytic reaction using TiO2 and ZnO is higher than that of homogeneous photo-Fenton technique. The optimum operating conditions in heterogeneous system occurred at 100 min of oxidation time, pH 5, and catalyst dosage 1 g/L that resulted in 21.8, 20.68, 60.9, and 55.17% of COD removal for TiO2, ZnO, TiO2/UV, and ZnO/UV, respectively. In contrast, both Fenton and photo-Fenton experienced their highest performance at pH 4 by obtaining 44.2 and 59.77% of COD removal, respectively. Eventually, kinetic study indicated that COD degradation can be well expressed by second-order pattern that reached higher correlation coefficient values by 0.999 and 0.998 for TiO2/UV and TiO2, respectively.Conclusions : Overall, it could be assumed that AOPs are reliable techniques to purify raw and complex raw industrial effluents.

Bioremediation of Total Petroleum Hydrocarbons (TPH) by Bioaugmentation and Biostimulation in Water with Floating Oil Spill Containment Booms as Bioreactor Basin

A crude oil spill is a common issue during offshore oil drilling, transport and transfer to onshore. Second, the production of petroleum refinery effluent is known to cause pollution due to its toxic effluent discharge. Sea habitats and onshore soil biota are affected by total petroleum hydrocarbons (TPH) as a pollutant in their natural environment. Crude oil pollution in seawater, estuaries and beaches requires an efficient process of cleaning. To remove crude oil pollutants from seawater, various physicochemical and biological treatment methods have been applied worldwide. A biological treatment method using bacteria, fungi and algae has recently gained a lot of attention due to its efficiency and lower cost. This review introduces various studies related to the bioremediation of crude oil, TPH and related petroleum products by bioaugmentation and biostimulation or both together. Bioremediation studies mentioned in this paper can be used for treatment such as emulsified residual spilled oil in seawater with floating oil spill containment booms as an enclosed basin such as a bioreactor, for petroleum hydrocarbons as a pollutant that will help environmental researchers solve these problems and completely clean-up oil spills in seawater.

Treatment of petroleum refinery wastewater by electrochemical oxidation using graphite anodes

An electrochemical oxidation method was performed in a batch electrochemical reactor using graphite anodes for treating an effluent obtained from Al-Diwaniyah petroleum refinery plant. The effective f process parameters like current density (4-20m Acm-2), pH (3-9), and NaCl concentration (0-3 g/l) on the COD and phenol removal efficiency have been investigated. The results reveal that the best conditions were current density 12 mA cm-2, pH 7, NaCl concentration 2 gl-1 at a treatment time of 60 minutes. Under best conditions of COD removal efficiency 100% and phenol removal efficiency 99.12% were obtained at current efficiency 33.5% and power consumption 59.9 kWh/kg COD. The anodic oxidation was proven to be efficient for treatment Al-Diwaniyah petroleum refinery effluent to get effluent with features in agreement with the standard limits for discharge to the environment at a lower cost.

Treatment of petroleum refinery effluent using ultrasonic irradiation

Ultrasonic irradiation is one of the advanced oxidation methods used in wastewater treatment. In this study, ultrasonic treatment of petroleum refinery effluent was examined. An ultrasonic homogenizator with a 20 kHz frequency and an ultrasonic bath with a 42 kHz frequency were used as a source for ultrasound. The effects of parameters such as ZnO amount, ozone saturation time, and type of ultrasound source on the degradation of petroleum refinery effluent were investigated. The degradation of petroleum refinery effluent was measured as a change in initial chemical oxygen demand (COD) and with time. According to the results, degradation increased with the addition of ZnO in an ultrasonic probe. There was also a positive effect of ozone saturation before sonication then applying ultrasound on the degradation for an ultrasonic probe. It was observed that there was no positive effect of ZnO addition and ozone saturation on degradation for an ultrasonic bath.