Membrane and Desalination Technologies - TCE Moodle Website

Treatment of Food Industry Foods and Wastes by Membrane Filtration 257
Fig. 6.16. Recovery of protein from potato starch effluent by RO.
marketed as protomylase, which is another saleable product with high potato fiber content
that may be used as a cattle feed.
As a result, the Avebe Foxhol plant effluent treatment problem was solved and waste
disposal costs were avoided. Water consumption has been reduced from 7 m 3 /tonne of
potatoes to 0.6 m 3 /tonne of potatoes by water recycle, with further cost savings. The two
by-products (protomyl PF protein concentration and Protomylase concentration) generated
extra revenues. The economic benefits depend upon the market value for the recovered byproducts
as well as water and wastewater charges.
In summation, the advantages of the continuous RO cleaner production system are (37):
1. Major reduction in the volume of process water consumed through the recycling of RO permeate
2. Total elimination of effluent discharge into the receiving water
3. The reduction in the quantity of water to be handled enabled the steam heat coagulation and
evaporation facilities to be reduced to half the size, resulting in capital and energy savings
4. Production of two saleable products from the effluent
5.5. Production of Yeast by Aerobic Fermentation, MF and NF
In a conventional process system for the production of yeast for the bakery industry,
aerobic fermentation is used for processing sugar, such as molasses. The yeast produced by
fermentation is then harvested by centrifugation or filtration, washed with water, and later
dried for sale. The conventional yeast production process generates an industrial effluent
which contains high BOD, COD, sugar, dark brown pigments, etc., and must be treated by the
evaporation and anaerobic digestion before its discharge into the POTW system. The cost and