Getting to Grips
with… FOG and
bioaugmentation
Of the tens of thousands of blockages in UK
sewer networks every year, almost three
quarters are caused by Fats, Oil and Grease
(FOG). Adding selected strains/mixed
cultures to wastewater (bioaugmentation)
has sometimes been met with cries
of 'snake oil' by those in innovation
departments frustrated by inconclusive
outcomes. Here, we look at the case for
bioaugmentation and how it compares to
alternatives such as jet washing
The Knowledge
www.wwtonline.co.uk | WWT | MARCH 2019 | 23
RAY TAYLOR,
CHIEF TECHNICAL OFFICER,
NEXT FILTRATION
Q: Firstly, why have
some water
companies been
sceptical about
using Enzymes?
As with all treatments, any
trial needs to be given a
fair chance. It's true that
enzymes are a catalyst that
break up FOG, but smaller
molecules of fat can congeal
further down the sewer
- or their impact reduced
by dilution – hence the
perception that what at first
appeared to have resolved
the problem, has reappeared
later. Over the years, albeit
with good intentions, there
has been plenty of dabbling,
but faced with such chronic
FOG problems and regulator
penalties we are at last
seeing some commitment
Q&A
from water companies and
their contractors to conduct
thorough studies that show
how bioaugmentation can
bring benefits; not just in one
area known for blockages,
but at the point of source,
and then much further along
the network and into the
treatment works. Additionally,
many water companies have
set up successful sewer
protection departments to
mitigate the impact.
Enzymes have also been
introduced to enhance the
effect of proteins, but in turn
this can enhance surfactants
that already take a very long
time to degrade. Enzymes
have a very different effect on
fat compared with bacteria;
breaking up long chain
triglycerides and liquefying
