ENVIRONMENT AND ENERGY
23
Wastewater: flows,
management, and as resource
Wastewater flows are as varied as its sources and the types of
constituents they contain, with the latter being a function of the former.
By Extracted from the United Nations World Water Development Report 2017
Figure 1: Wastewater
in the water cycle.
Figure 2: Wastewater flows.
Figure 2 provides an overview of the main wastewater
flows, from their generation at the source to their
ultimate fate. Uncollected wastewater (and all its
constituents) ultimately ends up in the aquatic
environment. This is also the case for wastewater that
is collected and disposed of without treatment, the
proportion of which can in some cases be considerable.
THE WASTEWATER MANAGEMENT CYCLE
Controlling and regulating the various wastewater flows
is the ultimate purpose of wastewater management. The
wastewater management cycle can be broken down into
four basic interconnected phases or steps:
1. The prevention or reduction of pollution at the
source, in terms of pollution load and volume
of wastewater produced.
Prohibiting or controlling the use of certain
contaminants to eliminate or limit their entering
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Wastewater treatment can allow for the separation of
water and other constituents, which can then be reused
or disposed of.
into wastewater streams through regulatory,
technical and/or other means. This step also includes
measures to reduce the volumes of generated
wastewater (e.g. demand management and
increased water use efficiency).
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November 2017 Volume 23 I Number 9