Management of effluents from field pea wet milling process using ultrafiltration technology

Abstract

A wet milling process is being used by a process facility in Portage la Prairie, Manitoba, to produce field pea fractions of protein, starch and fiber. The wet milling process requires approximately 700,000 L of fresh water on a daily basis, discharging similar quantities of high strength effluent for municipal treatment. Effluent surcharges based on strength and capacity requirement for municipal treatment are substantial to the plant. Current wet milling process technology results in an estimated loss of protein at the desludger operation of 1434 kg/day due to incomplete precipitation or process inefficiency; a double cost to the company in terms of product revenue loss and effluent surcharge. The use of an ultrafiltration membrane system was investigated to treat the protein desludger effluent generated in wet milling with the goal of protein recovery. Pretreatment of the desludger effluent by a carbohydrase enzyme Termamyl and use of celite for rapid floc settling was adopted prior to membrane treatment. (Abstract shortened by UMI.)