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ENVIRONMENT AND ENERGY
The extent and nature
of industrial wastewater
production (Part 1)
We describe the extent and nature of industrial wastewater production,
highlighting the opportunities from the use and recycling of wastewater
and the recovery of energy and useful by-products when addressing natural
resource challenges in the context of sustainable industrial development.
Extracted from United Nations World Development Report
The dawn of the industrial revolution in the eighteenth
century in the now developed countries signalled the
beginning of society’s dilemma with the fate of industrial
wastewater. Then and now, as is so often the case, it was
discharged into natural watercourses in the mistaken belief
that ‘the solution to pollution is dilution’ and that stormwater
was nature’s purgative. volume of wastewater produced and the volume that is actually
discharged, which is generally lower due to recycling. One
estimate suggests that the volumes of industrial wastewater will
double by 2025 (UNEP FI, 2007). Some consolidated information
is available from developed countries. In the EU, for example,
limited data show that wastewater generation has generally
decreased (Eurostat, n.d.).
Societal and environmental pressures have, over time, led to a
continuously growing movement that urged industry to reduce
the amount of wastewater it produces, and to treat it before
discharge. This has evolved into a significant paradigm shift, with
wastewater now being seen as a potential resource, and its use
or recycling after suitable treatment as a potential way to benefit
industry economically and financially. The data also shows that manufacturing is the greatest generator
of wastewater among the main industrial sectors (see Table 6.1).
Furthermore, data from a few countries indicate that industry is
a major polluter, as only a proportion of wastewater was treated
before being discharged (see Table 6.2).
This in turn complements the bigger picture of ‘green’
industry, corporate social responsibility (CSR), water
stewardship, and sustainable development, including the
SDGs, which refer to wastewater.
These considerations apply mainly to large industries, some of
which have a global reach into developing countries: many are
moving from high-income countries to emerging markets (WWAP,
n.d.). They have the size and resources to seize opportunities and
enter the circular economy. Lacking this momentum, small- and
medium-sized enterprises (SMEs) and informal industries often
discharge their wastewater into municipal systems or directly
into the environment, either of which creates another set of
challenges and potentially lost opportunities.
EXTENT OF INDUSTRIAL WASTEWATER GENERATION
As the volume of industrial wastewater is reported on a limited
and sporadic basis, the real extent of this potential resource is
largely unknown. Globally, data and information concerning the
volume of wastewater produced by industry are very deficient.
Moreover, a distinction needs to be made between the overall
November 2018 Volume 24 I Number 9
An atypical example of quite detailed country-level information
(see Table 6.3) is available from Canada, which conducts
biennial industrial water surveys that include data from
manufacturing, mining and thermal-electric generating industries
(see Box 6.1). Statistics Canada (2014) reports that the paper
industries produced almost 40% of the volume of manufacturing
discharges, with nearly 80% having secondary or biological
treatment, and accounted for 32% of the volume of recirculated
water, with primary metals accounting for close to 50%.
Overall, for manufacturing, the recirculation rate (recirculated
water as a percentage of intake) was nearly 51%. For the water
costs relating to manufacturing, about 38% went to effluent
treatment and almost 10% to recirculation. Thermal-electric
power was by far the largest user and discharger of water, of
which almost 58% went untreated mainly to surface water
bodies. Its recirculation rate was low, though the volume was
approximately double that of manufacturing.
NATURE OF INDUSTRIAL WASTEWATER
Data regarding the general characteristics and quality of industrial
wastewater are more available. The toxicity, mobility and loading
of industrial pollutants have potentially more significant impacts
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