Liquid effluent treatment in the dairy industry: a review

Abstract

The food industry, particularly the dairy industry, raises a great deal of concern regarding the intense consumption of natural resources and the generation of waste. The liquid effluents generated in dairy production processes have high levels of organic matter, fats, suspended solids, and nutrients and are considered the main source of pollution in these industries. In most products of milk origin, the serum is discarded along with the other effluents, becoming an aggravating factor for nature since the serum is approximately one hundred times more pollutant than domestic sewage. The treatment of generated wastewater is essential to maintain the good ecological and environmental state of the receiving means. The reduction of these can be obtained by means of recycling and reusing the components of these waters with the application of treatment of effluents such as physical, chemical, a combination of physicochemical processes and biological being aerobic or anaerobic. In this sense, the various existing treatments for dairy effluents were investigated, and it was possible to compare them through recent works by other authors to verify the efficiency of the applications of each one.