Treatment of petroleum refinery wastewater by electrochemical oxidation using graphite anodes

Abstract

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.

Anodic oxidation of synthetic refinery effluent on lead anode: mass transport and charge rate balance

“…Species concentration is another factor that is found to affect this balance. Trends where degradation efficiency is higher at early stages were reported (Ibrahim 2013;Jawad & Abbar 2019).…”

Application of Response Surface Methodology for Optimization of Phenol Removal from Simulated Wastewater using Rotating Tubular Packed bed Electrochemical Reactor

“…The stainless steel woven screens used in the present work have mesh no. 30 wire /inch with porosity of 0.7146 and a specific surface area of 38.06 cm -1 [24]. The cathode current feeder was attached to the shaft of a variable speed motor via a stainless steel rod (7 mm diameter and 100 mm length) fixed on the cathode feeder.…”

“…The schematic diagram of the electrochemical system: 1) cathode, 2) outside anode, 3) inside anode, 4) cell body, 5) jacket, 6) electrical motor, 7) power supply), 8) Ammeter, 9) voltmeter,10) water bath circulator Sodium sulfate (Na2SO4) was used as a supporting electrolyte and phenol as organic pollutant system. NaCl was used at concentration 1g/L [24]. All chemicals were of reagent grade.…”

“…The reason for such behaviour may be increasing of current density would be led to increasing the rate of reaction the chlorine with water whatever the value of pH, however, at low current density, the reaction rate may govern by type of oxidant at that pH. Hence disinfection is increased at acidic condition because hypochlorous acid is a strong oxidizing agent and would be governed on the reaction [24].The corresponding contour plot (3-b) confirms that a maximum value of the removal efficiency of COD lies in a small area in which the current density ranged between 7.5-15 mA/cm 2 and pH 3-7.0. (6).…”

“…In view of all aspects abovementioned, this research concerns with the using of indirect oxidation process via generating electrochemically an active chlorine to oxidize phenol using graphite anode. The choice of graphite as anode material is based on its low cost and availability as well as the good results obtained in our previous work on the treatment of petroleum refinery wastewater via indirect oxidation process with a graphite anode where a total removal of chemical oxygen demand (COD) has been achieved at lower energy consumption [24].…”