Wastewater treatment and resource recovery technologies in the brewery industry: Current trends and emerging practices

Abstract

Brewery is a water intensive industry where the waste stream consists mostly of wastewater originating from the processing and cleaning of equipment. A large amount of this wastewater is directly discharged into water bodies causing surface water contamination, which in turn is disastrous for human health and environment. This review intended to recommend waste effluent treatment and residual management for a brewery industry through a systematic literature review regarding the different industrial unit operations and processes, and waste streams, by focusing mainly on the current trends and emerging practices. In the malting process, it was proposed to treat the steeping water and condensate from the kilning stages with an anaerobic digestion reactor to remove organics while producing methane, then reusing the treated water to lower the amount of fresh steeping water required. In the brewing process, it was proposed to treat the wastewater with an upflow anaerobic sludge blanket (UASB) system to produce biogas, followed by an aerobic membrane bioreactor (MBR) to polish the effluent and possibly remove nutrients such as nitrogen and phosphorus. The effluent from MBR can then be passed through a reverse osmosis (RO) system to reuse the water. During the sludge handling process, it was proposed to collect the water from the thickening, dewatering and drying stages, and precipitate out struvite as a product and reduce the nutrient load going back to the wastewater treatment system. Alternatively, after struvite precipitation, the water can be passed through a RO system to reclaim some water for reuse. Future studies should be focused on emerging resource recovery technologies applied at a semi industrial level with detailed technological and economical assessments. In addition, sustainable actions should be promoted at various levels of the industry in order to suggest policies and technologies that will prevent further deterioration of the environment.