ENVIRONMENT AND ENERGY
21
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INDUSTRY NEEDS TO ‘PRODUCE MORE WITH
LESS’, WHICH IN THE CASE OF WATER MEANS
RUNNING DRIER
The upside of eco-industrial park wastewater
arrangements is similar to those for in-house recycling
(SSWM, n.d.). The downside includes the need for
long-term commitments to justify the initial capital
expenditures, and the need for further treatment to
meet some industries’ needs and possibly regulatory
approval hurdles.
Multiple-use systems (MUS) involving cascading reuses
of water from higher to lower quality within a river basin
may have industrial components, for example, where
domestic wastewater may be reclaimed for washing
and cooling (UNEP, 2015c).
With reclaiming of urban wastewater, industry can
assist on the other side of the wastewater equation by
using reclaimed urban wastewater from municipalities
(see Box 6.5): this inter-sector water reuse is
growing quickly in many countries (WBCSD, n.d.).
It is a very proactive measure of sustainability as it
reduces the requirements for freshwater intake, which
is particularly important in areas of water scarcity,
and reduces overall municipal discharges. Issues of
timing of wastewater availability and its transport to
the target industrial plants also need to be worked
out. In some cases, municipalities will custom-treat
wastewater for specific industries which may not need
perfectly clean drinkable water.
In California, for example, the Central and West Basin
Municipal Water Districts offer reclaimed water of
different qualities and costs, including process water
for petroleum refining. The State Water Resources
Control Board also promotes wastewater for power
plant cooling (California Department of Water
Resources, 2013).
WASTEWATER AND SUSTAINABLE INDUSTRIAL
DEVELOPMENT
Water is not only an operational challenge and a cost
item in industry, it is also an opportunity for growth as
the incentives for minimising water use (which includes
wastewater use and recycling) reduce costs and water
dependency (WBCSD, n.d.).
Industry needs to ‘produce more with less’, which in the
case of water means running drier (UNIDO, 2010). As
the reduction of freshwater intake is linked to a decrease
in wastewater discharges, there is a major role to be
www.plumbingafrica.co.za
BOX 6.5: INDUSTRIAL AND ENERGY USE OF
MUNICIPAL WASTEWATER
The Tarragona site of a water reclamation unit in the
south of Catalonia, Spain, utilizes secondary effluent
from two municipal wastewater plants, treating it for
industrial users. The Tarragona area is highly water
stressed and water unavailability hinders further
growth in the region. Water recycling in an industrial
park (a petrochemical complex) will free up existing
raw water rights to meet future local (municipal and
tourism) demand. The final target is to meet 90%
of the water demand of the industrial park from
recycled water (DEMOWARE, n.d.). Terneuzen is
situated in the southwest of the Netherlands. The
industrial site of Dow Terneuzen originally planned
to use desalinated seawater as a source, but the
increasing cost of this proved to be problematic due
to quality problems, corrosion, etc. As a result, the
nearby municipal wastewater treatment plant was
re-engineered to provide reclaimed water to the
industrial complex (10 000m 3 per day).
The water is used to generate steam and feed
its manufacturing plants. After the steam is used
in the production processes, the water is again
used in cooling towers until it finally evaporates
into the atmosphere (so it is ‘recycled’ a second
time). Compared with the energy cost needed
for conventional desalination of seawater for the
same use, Dow Terneuzen has reduced its energy
use by 95% by reclaiming urban wastewater
— the equivalent of reducing its carbon dioxide
emissions by 60 000 tonnes each year. Dow is
now using this experience gained in Europe at its
site in Freeport, Texas, USA (World Water, 2013).
The LIFE WIRE project is a LIFE12 project being
implemented in Barcelona, Spain, that aims to
boost industrial recycling of treated wastewater
by demonstrating the feasibility of water recycling
through the use of satellite treatments able to
produce fit-for-use water quality.
The project studies the feasibility of technology
configurations based on the combination of
ultrafiltration, carbon nanostructured material
filtration and reverse osmosis to use treated urban
wastewater in industries. The project technically
and economically assesses the benefits of using
the proposed treatment scheme over the current
conventional treatments in three industrial sectors:
electrocoating, chemical, and liquid waste disposal.
Source: Extracted from EC (2016)
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January 2019 Volume 25 I Number 1