Waste from Dairy Processing Industries and its Sustainable Utilization

Mostly, the waste materials from dairy processing industries are the waste water and generally considered to be the largest source of food processing wastewater in many countries. Dairy industries throughout the world varies in their sizes and the types of manufactured products due to which, it is hard to give any general characteristics. The dairy industry can be divided into several production divisions. Each division produces wastewater of a characteristic composition, depending on the kind of product that is produced (liquid milk product, cheese, butter, ice cream, powdered dairy product, concentrated milk like condensed milk, evaporated milk, etc.). Waste water in the dairy processing mainly arise from heating and cooling processes, the cleaning of equipment, spillage of milk and milk products, whey, pressing and brining, Clean-In-Place (CIP), and resulting from equipment malfunctions and even operational errors. Waste waters from dairy plants generally have a high organic load due to the presence of diluted milk and milk products; significant quantities of cleaning compounds and sanitizers and are high in sodium content (use of caustic soda for cleaning). The pH of the waste water varies widely due to the use of acidic and caustic cleaning agents. There are also large variations in the characteristics, volume, flow rate, and composition of the effluent generated on an hourly, daily, and seasonal basis. Like any other industries, the effluent from the dairy industry poses environmental problems like water and soil pollution due to the high amounts of nutrients and organic matter. Currently, sustainable innovational technologies have been targeted towards utilization of the waste for generation of compounds which have application in food, chemical, plastic, fuel, pharmaceutical, and other industries simultaneously solving pollution problem.