title: Treatment of oily wastewater of a gas refinery by electrocoagulation using aluminum electrodes.
abstract: Oily wastewaters are the most important discharges of gas refineries from an environmental point-of-view. In the present study, treatment of gas refinery oily wastewater by electrocoagulation using aluminum electrodes was investigated. The effects of electrode distance, initial pH, sodium sulfate (Na2SO4) as a supporting electrolyte, polyaluminum chloride dosage as a coagulant aid, and current density on the efficiency of chemical oxygen demand (COD) removal were examined. The results revealed that the COD removal rate increases by applying more current density and polyaluminum chloride and, to a lesser extent, Na2SO4 dosage. The results also showed that 97% COD can be removed at optimum operational conditions. Specific electrical energy consumption could be reduced from 19.48 kWh (kg COD removal)(-1) to 11.057 kWh (kg COD removal)(-1) using Na2SO4 as a supporting electrolyte. Gas chromatographic analysis of raw and treated wastewater also revealed that most normal hydrocarbons (nearly 99%) were removed during the electrocoagulation process.
authors.affiliation: Environmental Research Laboratory, School of Civil Engineering, Iran University of Science & Technology, Tehran, Iran. msaeedi@iust.ac.ir
authors.forename: Mohesn
authors.initials: M
authors.lastname: Saeedi
authors.forename: Amin
authors.initials: A
authors.lastname: Khalvati-Fahlyani
mesh_terms: D000535:Aluminum; D000536:Aluminum Hydroxide / Q000737:chemistry; D057919:Biological Oxygen Demand Analysis; D003029:Coagulants / Q000737:chemistry; D004564:Electrocoagulation / Q000379:methods; D004566:Electrodes; D004573:Electrolytes / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007492:Iran; D010578:Petroleum; D013431:Sulfates / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods*; D014876:Water Pollution / Q000517:prevention & control*
chemical_list: D003029:Coagulants; D004573:Electrolytes; D010578:Petroleum; D013431:Sulfates; C012036:sodium sulfate; C016213:aluminum oxychloride; D000536:Aluminum Hydroxide; D000535:Aluminum