SOURCES OF NUTRIENTS IN WASTE-WATER FROM INTEGRATED CATTLE SLAUGHTERHOUSES

The generation of the nutrients, nitrogen and phosphorus, by various p rocess areas of two large, integrated cattle slaughterhouses was studi ed to assist the better management of wastewater production and treatm ent. The Dinmore slaughterhouse, located near Ipswich, processes predo minantly grass-fed cattle, while the Beef City slaughterhouse west of Toowoomba processes grain-fed cattle. Nitrogen in the wastewater strea ms largely originated from the rendering plant (50% of the total daily generation at Dinmore and 62% at Beef City), the decreased cattle bon e process at Dinmore (22%) and the cattle holding yards at Beef City ( 32%). Phosphorus was generated primarily in the offal, paunch and trip e processing area at Dinmore (49%) and the holding yards at Beef City (57%). Nitrogen was present mostly as organic or ammonium nitrogen, wh ereas ortho-phosphate was the main form of phosphorus present in waste water streams. Significant differences were found in nutrient generati on between the two slaughterhouses, with the Dinmore plant releasing a lmost twice the quantity of nitrogen, and four times more phosphorus, per animal processed compared to the Beef City plant These results wil l assist management in allocating resources aimed at cleaner productio n by minimising and removing nutrients in the wastewater. Copyright (C ) 1996 IAWQ. Published by Elsevier Science Ltd.