Page 200 - Membranes for Industrial Wastewater Recovery and Re-Use

Industrial waters 169

Table 3.38 Representative data for effluent water generation

Source Flow Comments/assumptions Effluent water
(m3 day-') quality
PW generation 11 RO reject while water is made up to
PW storage vessel
13 RO reject while system is on recycle 75 ps cm-'
3 ED1 waste stream 200~s cm-l a
4 Pretreatment regeneration/backwash High salt and
contaminant content
Total 32
CIP. PW 12 Assume half of PW is used for final 5 ps cm-' *
clean rinse stage
CIP. process 24 Initial cleaning cycles - main contain 300-1500 pS cm-'
water residual product, cleaning chemicals, etc.
Total 36
WFI 0.8 10% blowdown over 8 hours
CIP. WFI 2 From the final rinse stages using WFI water
Total 28

Feed water conductivityassumed to be 300 pS cm-'.
a Candidate water for reclaim within water treatment plant: 30.8 m3 day-lin total, 54 pS cm-'.

day based on electrical usage, maintenance labour, microbiological testing,
chemical testing and validation activities. The operating cost of the reclaim
system would thus almost certainly exceed the potential saving, even without
considering recovery of capital cost, for a small system such as this.
Consequently, even without the barrier imposed by the pharmacopoeia
specifications and the views of government inspectors prohibiting the use of any
starting material other than drinking water, there is unlikely to be an economic
justification for reusing effluent water from the process. Any such water would
need to be combined with other effluent water from non-process applications on
site to make a dedicated reclaim system economically attractive. On the other
hand, reuse of some of the more dilute streams, specifically some of the CIP
streams and any other high-purity effluent streams within the existing
purification scheme would be much more likely to be cost effective.

3.5.4 Reuse opportunities
There appear to be no examples of any facility using recycled plant/process
effluent water treated to bring it up to the quality of drinking water and then
being used as the feed stream to produce PW or WFI and, under the current
regulations, there are no obvious reuse opportunities in the pharmaceutical
sector. One UK facility, based in a very remote rural location, submitted a
proposal to the Medicines Control Agency (MCA) in the UK for a facility that
included effluent recycling plant and they were told that this was not acceptable
to the inspection authorities. Since no local effluent facilities existed all their
plant effluent had to be collected and removed from site by tanker because of this
decision. This situation, which is global, may change if regulations are relaxed