The Exhaustive Reuse of Water in Food Processing
Authors: Gallop R A , Hydamaka A W , Clark B J , Carvalho L B 
Published: May 2018

The Food Industries are major users of potable water, and their survival in prosperity largely depends, almost everywhere, upon removing most of the constraints which must arise from Energy, Water and Wastewater problems that come from conventional designs, equipment and practices.

Feeding current and future populations will require major expansion of these Industries, preferentially in the Developing countries, many of which are arid. These lands must adopt approaches to water usage in each sector of their societies, which are usually the opposite of those which have been mostly used to date, if they are to be able to possibly cope with their needs. The responsible, efficient “Point-Source-Control” approach, must replace the irresponsible, disastrous “End-of-Pipe” outlook, if the worldwide, growing problems which afflict the Natural Water Cycle, due to Man's interactions with it, are to be controlled, and possibly reversed soon.

The major roles of Water in Food Processes are for Heat-Transfer and Mass-Transfer, mostly during in-Plant operations which can be mostly made highly cyclic, to great advantage. Except for constituent functions (as in Beer-making), about 90% of the water currently used, is unnecessary and harmful to water supplies, product yields, quality, process control, and waste management. In most processes, mains water is the worst kind to use, since it is the best solvent for the most precious nutrients and other quality factors in foods. Instead, purified solutions of each food, developed by Closed-Loops at each process stage, should be used, except for a small percent of potable water for “fill-up” and “make-up” per unit of production. The scientific cascading of such waters, as “bleed-offs” from higher functions, into distinctive process pools, from the last to the first stage of each Processing Line, can permit minimal water needs with maximal benefits of every kind. Yields and quality of foods much better than formerly possible in commerce, can be achieved, at attractive economics. And virtual independence of water supply, and waste discharge constraints, including Geographical/Climatic ones, can become readily possible.

The symbiotic use of solid wastes from food plants, as filter-aids, as fuels, and as substrates for the on-site production of very good Activated Carbons, is the best way to solve many problems, by converting them into the best, most rapid de-pollutant known, of many uses on-site and elsewhere. Its skilful use, can permit food processing waters, especially the edible ones normally rejected as “wastes”, to be used as “Processing Aids”, to greatly improve the productivity of such lines; while permitting the same volume of original water to be used to “practical exhaustion”, with safety, over many weeks or longer, if desirable or necessary anywhere. The recovery of water from process “plumes” by condensation for Heat Recovery, or from process streams (e.g. whey), can soon give Plants more than 100% of daily on-site water needs, for make-up to the virtually Closed-Loop Total Process Systems now required.

The Poster showed the essential principles and practices recommended by the authors, which permit the Food Industry to become largely independent of the major water-related constraints of History, as the basis of its design for the 21st Century. They are of wide applicability, in every sector of water usage.