Water Reuse

Historically, water reuse was given little consideration. Water is relatively abundant in nature and reuse was considered hazardous due to bacterial contamination. Contamination potential (Figure 8.2.1) shows that, in washing fruit, unless 40% of the water is exchanged each hour, the growth rate of bacteriological organisms becomes extremely high. To overcome this, other means of control such as chlorination must be used. The importance of chlorination in maintaining satisfactory sanitary conditions is graphically shown in Figure 8.2.2. When chlori-nation was discontinued, the bacterial count more than doubled. As soon as chlorination resumed, bacterial counts were again brought under control.

Water conservation can be achieved through counter-flow reuse systems. Figure 8.2.3 outlines a counterflow system for reuse of water in a pea cannery. At the upper right, fresh water is used for the final product wash before the peas are canned. From this point, the water is reused and carried back in successive stages for each preceding washing and fluming (the transport of the fruits by flowing water in an open channel) operation. As the water flows coun-

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