McDermott: Trends in Offshore Oil & Gas - GineersNow GineersNow Engineering Magazine Issue No. 021, McD | Page 4

CREATING VALUE FOR INDUSTRY
41
Sponsored Article
Robert Wiseman
Dairies
Reducing water consumption for a higher
economic value and a lower carbon footprint
O
ne of the major costs in milk processing
is water: 1.3 liters of water is needed for
every one liter of milk processed. On top of
this, 4.2g of chemical oxygen demand (COD)
is produced from every liter of milk processed,
which is then discharged into wastewater.
Robert Wiseman decided to optimize its
water and wastewater use by aiming to
reduce water consumption across its dairy
network by 25% over a five year period.
The project was started in their main dairy
plant located in Bridgwater, which processes
125 million liters of milk per day.
Veolia Water Technologies (VWT) is
supporting Robert Wiseman’s project by
providing a Dissolved Air Flotation (DAF)
system and a membrane bioreactor (MBR)
to reduce COD. The quality of the discharged
effluent more than meets the environmental
requirements. In fact, the quality of the
treated effluent was so good that Robert
Wiseman wanted to reuse it.
VWT therefore proposed its reverse osmosis
(RO) system: MegaRO TM to recycle the effluent
in order to use it for the CIP (Cleaning in
Place) system. The MegaRO technology uses
a membrane to remove 99% of residual COD,
dissolved salts and bacteria from the treated
process wastewater, producing water of equal
or better quality than the mains supply.
VWT was one of the early pioneers of
MBRs, thanks to its Biosep process , and
using this expertise VWT were able to feed
the MBR effluent directly to the MegaRO
system with no set-backs. Robert Wiseman
became the first dairy industry business in
the UK to install a RO recycle system, enabling
them to recover 200m⁳/day of process
wastewater.
The reverse osmosis process is driven by
pressure, but the MegaRO’s low-pressure
membranes and high-efficiency pumps make
it one of the most energy efficient systems
on the market. Low energy use means not
only reduced carbon emissions but also low
operating costs. Moreover, the quality of the
waste concentrate stream from the MegaRO
is still good enough for the effluent to be
discharged directly into the drainage ditch.
"Because the operating cost of the MegaRO
is low, the recovered water actually costs less
than mains water even after including capital
amortization. We expect to get a payback on
the £130,000 (approx. €153,000) investment
in about two and half years." said Eleanor
Walton, Robert Wiseman Dairies' project
manager.
Although the plant has only been in
operation for six months, Walton had
enough confidence to be talking to
Veolia Water Technologies about
a second plant to recycle another
80m⁳/day of wastewater. “We also
want to roll out this kind of technology
to some of our other sites where they have an
expensive sewer discharge” she says. �
Robert Wiseman Dairies operates six
dairies, 14 distribution depots and
employs more than 4,700 employees.
Robert Wiseman Dairies supplies a third
of the UK’s milk.
DAIRY
RECYCLING
50% OF ITS
WASTEWATER