Water footprint and wastewater quality assessment of yeast single cell oil production: Gate to gate approach for industrial water sustainability

Effective water resource utilization and sustainability for industrial operations is a growing concern. With increased industrial water demand, abstraction and water quality changes are rising. In India, distilleries generate more than 40.4 billion litres of effluent daily within the fermentation industry. Water, a public good with market and opportunity costs, needs effective mapping and management. Emerging distillery processes such as yeast lipid fermentation, if developed along with water sustainability, could aid in advancing water resource management. In the scope of this idea, the present study focuses on assessing the water footprint and water quality mapping for Rhodotorula mucilaginosa IIPL32 lipid production using crude glycerol, a by-product of the biodiesel industry. The assessment was based on primary data generated during the 500 L plant scale operation. The process's blue water footprint was assessed by applying a chain-summation approach, and the grey water requirement was determined by measuring water quality parameters for the effluent streams. The process's net blue and grey water footprint were estimated to be 3.87 and 23.66 m3 water/kg of lipid, respectively. Water quality index ratings were identified for all the respective water streams within the processing system, and human risk factors were estimated. The results suggested proper treatment of the spent broth, whereas the secondary effluent stream from cleaning operations could be reutilized within the system. Quality mapping also suggested that the effluent's high organic and mineral load can be processed for water and material recovery, which may significantly reduce the process's grey water and pollution load.

Automated summary

Effective utilization of water resources and sustainability in industrial operations is a growing concern, especially with increased water demand and changes in water quality. The generation of effluent by distilleries in India is a significant issue, highlighting the need for effective water mapping and management. This study focuses on assessing the water footprint and quality mapping for lipid production using crude glycerol, aiming to promote water resource management and reduce pollution load.