Uses of Waste Starch - The Economic Utilisation of Food Co-Products - page 71

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Figure 5.4 Representation of use of a switching waste starch-based adhesive to
facilitate facile separation, allowing full recyclability of components within
a closed-loop system.

backing layer could be either chopped and melted or melted and sieved to
recover the glass scrim. This could then be used without any composting steps
as the correct amount of filler, etc., would already be contained in the material.
The fabric layer, after separation, could be shredded and sold to needle-felt
manufacturers or further processed. This would entail the nylon being
separated from the spun-bonded polyester primary fabric and reprocessed to
form yarn for the carpet-tile fabric layer. This would see the complete recycling
of the carpet tile without the need to downgrade any of the components, as
shown in Figure 5.4. Besides, in an increasingly environmentally conscious
society, a reusable system offers many advantages for end-users to recycle. 48

3 .

5.3.3 Waste Starch-Rich Water from Potato Processing
During potato processing, which involves different activities, such as cleaning,
peeling and cutting, water is continuously required. As a result, a large amount
of wastewater is generated from this process. According to Russ and Meyer-
Pittroff, the potato processing industry has a specific waste index (the mass of
accumulated waste divided by the mass of the saleable product) of 0.3-0.5,
which is relatively high and comparable to that of the meat and sugar
industries. This waste contains a high amount of protein and starch. 49 Starch in
this wastewater exists in the form of free suspended solids, which can be
separated using a variety of methods. Common water-starch separation tech-
niques include the use of hydrocyclones and centrifuges. 50 Moreover,
membrane technologies, such as membrane bioreactors and microfiltration, has
increased their popularity in wastewater treatment. 51 The use of membranes
has also exhibited promising results in recovering starch from wastewater
treatment in starch processing. 52 The membrane module configuration can