Use of high-pressure pumps that are used for cleaning floors,
machines, and extractor’s filter cloth.
Regular check and reparation of piping leakages.
Take up all product spills from the floor before cleanup once
a day in the morning. This helps to reduce the amount of
wastes flushed down the drains.
Collecting leftover starch from machines after shutting down.
The dried starch can be sold as the second grade starch.
4.1.2. Reuse/recycling of water in the production processes
Since a great amount of water is required in tapioca starch
processing, most of the studied plants have water reuse and recycling
at some point. However, their measures are demonstrated
ineffective. The following practices are proposed.
Reuse of wastewater from a maturation pond for plant cleaning.
Most tapioca starch plants employ conventional biological
treatment systems. The systems comprise anaerobic and facultative
ponds in series. Since the properties of treated wastewater
in the finishing pond meet the Thai effluent standard, the
wastewater is reusable for the purpose of floor cleaning.
Recycling of water in the production process. As shown in Fig. 1,
a typical plant without water recycling generates wastewater
streams from almost all of the starch-processing stages. To
minimize wastewater sources, a starch processor should consider
water recycling in the production lines. Shown in Fig. 4 is
the proposed water recycling to one of the studied plants. In
the existing process, the reclaimed water from the second
starch separator and starch dewatering centrifuge was
returned for use in the fine fiber separating and first starch
dewatering stages, respectively. To obtain more efficient use of
water, the reclaimedwater from the second dewatering stage is
reused in the coarse fiber-separating stage. Since the used
water from the first dewatering stage contains protein impurity,
it is not suitable to be reused in the other stages except for
root washing. In the fibrous residue handling streams, the
reclaimedwater from a screwpress can be reused in the fibrous
dewatering stage, while the used water from this stage can be
returned to the chopper and grinder because the water contains
extracted starch. This proposed water recycling indeed