Water & Wastewater Asia March/April 2024

FOCUS
Navigating
wastewater treatment
for environmental harmony
By Ken Kershner, global commercial director, Nuvonic
UV treatment eliminates
harmful pathogens without
introducing additional
chemicals into the waterways
UV VS CHEMICALS: A SHIFT IN
WASTEWATER TREATMENT
The dichotomy between UV and
chemical treatments underscores the
importance of choosing sustainable
and environmentally-friendly options. In
contrast to chlorine, UV treatment offers a
unique advantage by eliminating harmful
pathogens without introducing additional
chemicals into the waterways. Cities and
wastewater treatment facilities employing
chemical methods face potential
repercussions, altering the ecosystem and
creating a stark contrast in environments
surrounding outfalls. This difference
is noticeable in areas where wildlife
struggles to survive due to the absence of
essential components in the ecosystem.
In the complex landscape of
wastewater treatment, the choices
made in safeguarding waterways play
a vital role in determining the health
of our environment. A study shed light
on the alarming volume of raw sewage
discharged by treatment works in England
and Wales, UK, revealing an estimated
11 billion litres in 2020. The urgency of
adopting safe and effective wastewater
treatment methods becomes increasingly
evident in the face of such statistics.
The use of chlorine in traditional
wastewater treatment poses
environmental threats, when released
into rivers and streams. This chemical,
intended for disinfection, proves harmful
to aquatic life by causing fish kills
and disrupting microbial communities
essential for ecological balance.
Chlorine’s reaction with organic matter
produces carcinogenic
byproducts, impacting both water
quality and the health of ecosystems.
Additionally, its introduction alters water
chemistry, contributing to issues like
eutrophication — a process that involves
an excessive growth of algae — often
spurred by the release of nutrients like
phosphorous and nitrogen, which can
lead to oxygen depletion and negatively
impact aquatic fauna.
However, a proven alternative exists in the
form of UV disinfection, a chemical-free
approach that not only reduces harmful
pathogens but also contributes to the
preservation of water quality. We explore
the implications of UV compared to
chemical treatments, the challenges
posed by stormwater runoff, and the
need for a comprehensive approach to
wastewater treatment.
THE DANGERS OF CHLORINE
TRANSPORT AND CHALLENGES OF
STORMWATER RUNOFF
The choice between UV and chemical
treatments gains further gravity when
considering the dangers associated
with transporting chlorine. The 2005
collision of two Norfolk Southern trains in
Graniteville, US, serves as a reminder of
the perils of chlorine transportation. This
incident, which resulted in the deadliest
chlorine release in US history, left 9
people dead and hundreds injured. The
community still bears the physical and
emotional scars, with heart and breathing
problems, body pain, and lasting
emotional trauma plaguing the survivors.
One of the pressing issues in wastewater
treatment is stormwater runoff, a
phenomenon that overwhelms treatment
plants during heavy rain. The runoff,
laden with various pollutants, poses a
challenge for cities striving to maintain
36 Water & Wastewater Asia | March-April 2024