The Wealth in Brewery Effluent – Water and Nutrient Recovery Using Alternative Technologies

High rate algal ponding (HRAP) and constructed wetland (CW) technology was used to remove nutrients from brewery effluent, thus recovering water and producing algal biomass. The HRAP/CW system was effective in reducing chemical oxygen demand (COD) from ca. 150 mg/L to below 75 mg/L, and ammonia from 30 mg/L to below 1 mg/L. The HRAP was initially inconsistent in phosphate removal, but phosphate levels within discharge standards were achieved in the combined HRAP/CW system. The HRAP/CW system was ineffective at removing chloride from the effluent, which persisted at levels of 200-500 mg/L. Hydraulic retention time in the HRAP was reduced from 13 to 3.8 days by optimising flow rate for maximal ammonia removal. The HRAP/CW was highly resilient to variations in effluent quality. The recovered water was successfully used to produce hydroponic lettuce and fish, and harvested algae were made available for potential use as a fish feed ingredient.