Date of this Version
The Food Energy and Water Nexus (FEW Nexus) is the inseparable connection linking these resources. The concept of the FEW Nexus within the food industry addresses the connection of water and energy as key members of food production. The steady increase in population and the increase in food demand are directly related, therefore, the need for water and energy. Immediately taking on this critical challenge will lead to tangible impacts on the water and energy crisis facing the food system. To reduce the distance between process productivity and resource efficiency it must first be determined, within food processing, where water and energy are being consumed. Therefore, this research focused on determining opportunities for water-energy optimization and wastewater reduction in a medium sized dairy. The partnering plant processed pasteurized fluid milk.
To reach the overarching objective, the first task was to develop a baseline of the current consumption of water/energy and wastewater generation. Results from the partnering plant indicate that the production of one gallon of pasteurized fluid milk demands 0.13 kWh and 0.01 Therms of electricity and natural gas, respectively. In addition, every gallon of pasteurized milk produced demands 0.87 gallons of freshwater. On average, 53.08% of the water used to produce milk is consumed during the cleaning stages. This consumption of resources places a large financial strain on producers. Annually, the medium sized fluid milk processing plant spent more than $47,000 on energy and water utilities. The second part of this research explored the efficacy of water reuse during cleaning operations. The increase in reuse cycles is directly related in increases in COD, Turbidity, TSS, TP, and TN. The reduction in surface tension with reuse solution is thought to advance the cleaning ability as hydrolysis of milk components have surfactant properties. Before caustic cleaning solution can be reused, the efficacy must be evaluated. To uphold the integrity of plant safety, a 3-log reduction in attached bacteria should be achieved. CIP operations, including a sanitizer rinse, as noticed in treatment 3 and 5 with solutions 0-50N experimental reuse solutions, showed a 3-log reduction in bacterial density of P.aeruginosa. Therefore, experimental caustic solutions showed the potential for reuse.
Advisors: Curtis Weller and Yulie Meneses