A Review on Different Treatment Possibilities of Dairy Wastewater

Dairy industry is one of the leading consumer of water and producer of wastewater. Increased demand of dairy products results in rapid growth of dairy industry and hence wastewater production increases. Dairy effluent contains high concentrations of organic and inorganic substances that cause eutrophication in water bodies. This review study emphasizes on various treatment methods of DWW for period 2002 to 2022. Dairy wastewater imposes serious environmental concern because of the presence of wide range of fatty acids, proteins, nutrients, and other organics. These contaminants are difficult to treat in single step conventional treatment technique. In recent years much attention has been given for integrated system of dairy wastewater (DWW) treatment. The present review has deep insight for ongoing development in various treatment techniques of dairy wastewater. Moreover, this article intricate issue related with treatment followed by a brief discussion on the biological technique and special emphasis has been on the bio-filtration process. Extensive review study found that bio filtration method is environmentally sustainable and economically affordable technology as it requires minimal maintenance and low operating cost; filter media can be coarse gravel, stone, bio-carrier. Treatment process provides a separate area for the growth of necessary bacteria to complete their nitrogen cycle. Literature survey found that the bio-filtration process has the efficiency of removing BOD, COD, TP, TN (91.7-97.5, 74.1-99%, 98.3%, 88-91.5%). Fresh water crisis demands the reuse of DWW for non-potable purposes. Pre-treatment, anaerobic and aerobic biological processes are the most widely used DWW treatment techniques. Reuse of DWW in food, plastic, fuel, health and pharmaceutical industries helps to convert its zero value to a potential resource.