Scale-up economic assessment and experimental analysis of MF–RO integrated membrane systems in oily wastewater treatment plants for reuse application

• High quality water was produced by MF–RO pilot trial for reuse applications.
• Economic assessment of IMS-based oily wastewater treatment plants was carried out.
• Cost exponential factors were derived for a wide range of plant sizes.
• Behavior of different cost components with respect to plant scale was analyzed.
• Benefits of large scale plants were depicted through economy of scale.

Cost analysis of integrated membrane system (IMS)-based industrial wastewater treatment plants (WWTPs) was carried out in this study. Five plants with different capacities were designed based on MF–RO technology following a three-stage pretreatment to produce reusable water from industrial oily wastewater. A cost model was developed to analyze economic impacts of scale-up on different plant sizes and effect of economy on scale. The cost model provided a useful preview for scale-up purposes by explicating economic behavior of different cost components with respect to plant size, and presenting the benefits of large scale plants over small ones. An experimental MF–RO pilot was used to evaluate the applicability of designed IMS-based WWTPs for treatment of a typical gas refinery wastewater. The proposed process showed significant ability in the removal of oil and total dissolved solids, in which the high quality of the treated water met international regulations for a variety of reuse applications.