Treatment of phenolic-wastewater by hybrid technologies: A review

Wastewater containing phenol and its derivatives causes global concerns on Health, Safety and Environment (HSE). A number of technologies (e.g. physical, chemical, electrochemical, biological) have been proposed for the treatment of such wastewater, all having their own pros and cons. Recently, hybrid/coupled technologies have emerged quickly to overcome the barriers of each technology, with good flexibility and high efficiency. Such hybrid/coupled technologies mainly encompass four categories: 1) physical-physical; 2) physical-biological; 3) physical-chemical; and 4) chemical-biological technology couplings. Recent progress in these technologies is reviewed in this article, with an emphasis on the fundamental mechanisms, performance, limitations and prospects. It is demonstrated that such coupled technologies (particularly, the advanced oxidation process or AOP-based and bio-based processes) offer a number of advantages over an individual technology alone, presenting increased technological efficiency for the treatment of Phenol-containing WasteWater (PWW).