ABSTRACT

206Discharge of oily wastewater complying with both resource reuse suggestions and environmental regulations is a major challenge nowadays. The objective of this chapter is to elucidate the current status and prospect of development in oily wastewater treatment. The origin, characteristics and environmental impacts of the oil are herein outlined. The techniques for oil treatment including membrane separation, vacuum evaporation, chemical treatment, floatation, filtration, coalescence, deep bed filtration, electrical methods, adsorption, microwave and ultrasound technologies are elaborated. Among the various methods available, adsorption is the most promising choice of treatment owing to its robustness, efficacy and feasibility with the usage of an appropriate adsorbent. Hence, novel approaches to oil adsorption through surfactant modification, alkali treatment, microwave treatment, ultrasound application and/or combination of these approaches are proposed to maximize the oil removal efficiency and to minimize the adverse impacts of the disposal of oil into the environment. In addition, ecofriendly biosorbents such as, corn husk in terms of their adsorption capacities, process factors and pretreatment methods have been highlighted as an attractive alternative for the treatment of oil in wastewater.