A Comparative Review and Multi-criteria Analysis of Petroleum Refinery Wastewater Treatment Technologies

Abstract

The global economy’s continued dependence on fossil fuels is associated with a multitude of environmental concerns, including the production of hazardous wastes in petroleum refineries. Large quantities of petroleum refinery wastewater (PRWW) are produced daily, requiring the development of appropriate treatment methods. Activated sludge biological treatment is commonly used to treat PRWW, however this treatment method has a high sludge production, high operational time and may not be optimally suited for the variable loading conditions of refineries. Multi-criteria analysis is a tool capable of evaluating different wastewater treatment technologies through the weighted consideration of multiple environmental and economic factors. The following methods of treating PRWW were reviewed and evaluated using a multi-criteria analysis (MCA): biodegradation, advanced oxidation processes, electrocoagulation and microbial fuel cell technology. The MCA considered the removal efficiencies, sludge production, cost-benefit, process complexity and operational time of each method and was conducted under six different weighting scenarios. Advanced oxidation processes were preferred by this analysis under all six scenarios, with overall index scores (OIS) ranging from 7.84 to 8.51 out of a possible 10 points. Biodegradation of PRWW obtained was found to have the greatest overall removal efficiencies, however the high operational time and sludge production of this method resulted in a maximum OIS of 7.59. Electrical methods, such as electrocoagulation and microbial fuel cell technology required further improvements in removal efficiencies to be considered as a standalone treatment method. Further research into all methods, particularly microbial fuel cell technology is recommended.

DOI: http://dx.doi.org/10.5755/j01.erem.74.4.21428