Sustainable Technological Advancements for Dairy Waste Water Treatment-A Review

The dairy industry has global importance due to its essential contribution towards human nutrition as well as high economic opportunities. There is a consistent and steep growth in India's dairy sector in the last few decades and now India is one of the major milk-producing countries in the world. Highstrength dairy wastewaters, if discharged without proper treatment, severely pollute the receiving water bodies. In this scenario 'Waste as a resource' concept has been gaining the interest of researchers. The present review delineates different technological advancements for treating dairy wastewater and compares which is the better option in terms of sustainability. In the aerobic process, advanced bioaugmented systems which use bacterial and fungal consortia were found to be effective and sustainable with biological oxygen demand removal of 78.7% and 74.7%. Physio-chemical methods using natural coagulants like Moringa oleifera (MO) and pomegranate peel powder were also found to be effective with 81.8 % nitrogen removal from dairy wastewater treatment. Phytoremediation using water fern (Azolla pinnata R. Br.) was found to be efficient with dissolved solids reduction efficiency of 71.56 %. The fluidized bed anaerobic reactor unit was found to generate a biohydrogen content of 35.72±9.43% when the OLR was 53.25± 7.81 kg. COD m– 3 d–1. Microbial fuel cells treatment of real dairy wastewater (RDW) using Shewanella algae (MTCC-10608) has generated maximum current density and power density of 141 mA/m2 and 50 mW/m2 respectively. These two technologies are better sustainable options for dairy wastewater treatment since waste to energy aspect is satisfied.