WC128 JanFeb2023 - Magazine - Page 22
WASTEWATER
1930s
1940s
1950s
Synthesis/
Development
1960s
1970s
1980s
Unrestricted Commercial Usage and
Production in Various Sectors
1990s
2000s
2010s
2020s
Phase out/Reduction
/Alternatives
PFAS and Biosolids
Status, technologies, and trends BY LUXMY BEGUM, PH.D., P.ENG., PMP
Cause for concern
While research to better understand the health
effects of PFAS is underway, we know that PFAS
compounds pose various health risks to human and
biotas, including disruption to the immune system
and liver function, increased risk of thyroid disease
and blood cholesterol levels, and cancer—especially
Luxmy Begum
Luxmy Begum is a professional engineer
with over 20 years of experience in
wastewater and biosolids sector
managing and delivering various projects
both nationally and internationally.
22
WATER C AN ADA • JANUARY/ FEBRUARY 2023
in those communities with higher exposure to PFAS.4
It is everywhere: products, air, water soil, and waste,
including sludge and biosolids. And its persistent nature means that they can remain and bioaccumulate,
both in the environment and in our bodies.
Biosolids and PFAS
Biosolids are widely used as soil amendments or
fertilizer. Land application of biosolids promotes
circular economy as it enhances soil health by returning nutrients and micronutrients back to the land
and by sequestering carbon in soils, which helps in
reducing the impacts of climate change. It also aids in
the reduction of synthetic fertilizer and pesticide use
by introducing green soil amendment products. In
addition, land application of biosolids diverts a valuable organic product from the landfill. A common
practice in both the United States and in Canada, it
is particularly important to Ontarians as Ontario’s
landfills will reach the end of their lives within the
next 10-12 years.
Problematically, the same treated biosolids that
are being used as soil amendments have been found
to contain PFAS. As a result, some public resistance
and fear has arisen about the potential health risk associated with the land application of biosolids, along
with concern that the PFAS found in the landapplied biosolids will further contaminate surrounding surface and groundwaters.
However, the PFAS detected in wastewater,
biosolids, and other residuals are considered to be
trace amounts (parts per billion or less).5 As well,
WAT E R C A N A D A . N E T
Clearflow
P
ER- AND POLYFLUOROALKYL SUBSTANCES (PFAS) are a group of humanmade compounds that are used as surfactants,
lubricants, repellents (for dirt, water, and
grease) and can be found in certain firefighting foams, textiles (including carpets, furniture, and
clothing), cosmetics, and in food packaging materials.1 They are also used in a variety of other industries, including aerospace, automotive, construction,
electronics, and military.2 PFAS are made up of a
carbon chain with at least one carbon atom that has
two or three fluorine atoms attached to it, creating an
incredibly strong carbon-fluorine bond that results
in chemicals that do not easily degrade in the environment.3 Because of this property they are known as
forever chemicals.
