34
ENVIRONMENT AND ENERGY
In the case of water reuse, this occurs often at a
local scale. By-products of one industry become
feedstocks in another. Similarly, process cooling water
may be used for heat recovery or for productive use
(Industrial Symbiosis Institute, 2008). Sometimes,
partnerships share the management of utilities or
ancillary services.
Wetlands form
part of the
wastewater
treatment
ecosystem.
The local wastewater utility in the city of Kolding
was facing the challenge of having to clean runoff
from a highly polluted industrial area to protect the
ecosystem of a small river nearby.
The river was polluted with oil and hazardous
substances derived from the industrial area
where trucks were being loaded and a variety
of materials were stored outside on the storage
yard. To solve this problem, they applied the
HydroSeparator®, which is an automated and
effective solution to improve water quality in
various recipients while minimising the need
for retention basins at a much lower total cost
of ownership.
The maximum capacity of the HydroSeparator®
was determined by the requirement of a maximum
flow of 200 l/s discharges to the small river. It is
built of two standard HydroSeparators of 100 l/s
each, which can operate concurrently or separately.
Today, the plant operates automatically with
very low operating costs and can be monitored
and controlled from the Internet as well as the
connected SRO-system from the wastewater utility
Kolding Spildevand.
Source: Extracted from State of Green (2015)
The United States Environmental Protection
Agency (US EPA, 2004) gives a good account of urban
reuse systems that provide partially treated (fit-for-purpose)
wastewater for various non-potable purposes, including:
• irrigation of public parks and recreation centres,
• athletic fields,
• school yards and playing fields,
• highway medians and shoulders,
• landscaped areas surrounding public buildings
and facilities,
• irrigation of landscaped areas surrounding
single-family and multi-family residences,
• general washdown, and other maintenance
activities,
• irrigation of landscaped areas surrounding
commercial,
• office and industrial developments,
• irrigation of golf courses,
• commercial uses, such as vehicle washing
facilities, laundry facilities, window washing, and
mixing water for pesticides, herbicides and liquid
fertilisers; and
• ornamental landscape uses and decorative
water features, such as fountains, reflecting
pools and waterfalls.
BOX 4: TREATING RAINWATER RUNOFF
FROM INDUSTRIAL AREA, KOLDING, ENMARK
October 2018 Volume 24 I Number 8
www.plumbingafrica.co.za