Evaluation of various methods for nutrient recovery from blood stickwater in the meat industry

A critical issue for the meat industry is the loss of valuable nutrients in the stickwater arising from blood processing, and the consequent environmental burden. This work evaluates the effectiveness of various treatment methods including heating, pH adjustment and lowpressure membrane filtration for nutrient recovery from stickwater. Despite the blood having been processed through a decanter, over half of the residual proteins could be recovered by a simple settling step. After further removal of particulates in the stickwater by laboratory centrifugation, ultrafiltration removed 40% of the chemical oxygen demand (COD), while reducing the pH removed 24% of the COD. None of the methods tested could effectively reduce phosphates, the maximum removal being 7% by ultrafiltration.