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 (MCA) 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: biodegradation, advanced oxidation processes, electrocoagulation and microbial fuel cell technology. The MCA considered 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.

Refinery effluent water treatment: An integrated approach

“…Based on the nature of the activities, these effluents contain extremely high level of dissolved salts, oil grade and other microbial pollutants. Though tremendous efforts have been made to curtail such pollutants, the refinery effluent water remains a major concern [3]. The projected rise of demand for petroleum products in the forthcoming years especially for the light olefins has been put at 44% and this could further exacerbate the growing concern on the pollution impact that these heightened activities could cause.…”

A Review of the Processes Associated with the Removal of Oil in Water Pollution

“…Wastewater-containing petroleum pollutants are a significant challenge for conventional treatment plants, which often do not adequately remove these pollutants. To limit petroleum product pollution and improve discharge water quality, more efficient wastewater treatment technologies are continually being researched, developed, and implemented [10,11]. Governments, companies, and research groups around the world devote considerable efforts and resources to process and remove oil pollutants from water [1,[12][13][14].…”