Converting Industrial Food Process Water into High Quality Drinking Water for Direct Reuse

摘要

Global water shortage problems and environmental sustainability targets are becomingrnincreasingly attractive, not just at the international level, but also within the UnitedrnStates. Today, groundwater is being pumped faster than it is being replenished.rnUnderground aquifers, the source of 60 percent of U.S.’s fresh water, are being depleted,rnand surface water in lakes and rivers is endangered by our population demands. Morernthan 85 percent of the world’s fresh water is consumed in the agricultural and industrialrnsector. Manufacturing operations across the globe need to identify solutions to reducerntheir water footprint and begin working toward more sustainable water scenarios. One ofrnthe most promising sustainable solutions to the growing global water shortage is waterrnrecovery and reuse. The objective of this project was to identify the most viablerntechnology to convert food process water into high quality drinking water for direct reusernat food manufacturing plants. Major treatment processes of this advanced water recoveryrnand recycling system include screening, equalization, pH adjustment, primary clarifier,rnMembrane Bioreactor (MBR), Activated Carbon (AC), Ultraviolet (UV) disinfection,rnLow Pressure Reverses Osmosis (LPRO), water stabilization, and chlorination. Frito-LayrnInc. (A Division of PepsiCo), as part of its robust and thoughtful approach tornsustainability and reducing its environmental footprint, has selected its manufacturingrnplant in Casa Grande, Arizona to be the first full-scale “Water recovery and reusernfacility” in U.S. Several design, construction and operational lessons were learned duringrnand after the start-up of this project. LPRO membrane fouling was the most challengingrnissue which required much time and investigation to resolve and develop a feasiblernsolution. Currently the combined MBR-Activated Carbon-LPRO membrane system isrnrunning at 69% water recovery and producing high quality permeate which meets USrnEPA Primary and Secondary drinking water standards. Annually, this plant will savernmore than 100,000,000 gallons of fresh water in State of Arizona.