Fresh air saved
neighbourliness in Skjern
Fresh air blown along the bottom of a tank containing
wastewater from Skjern Papirfabrik (paper mill) has
saved far more than just the neighbourliness with the
town of Skjern.
During several years the tank contents have produced
an odour similar to that of rotten eggs.
As time went on, the number of protests from the ”odour-plagued”
citizens created a mood in the media, which almost made the
factory give in - even though more or less all possibilities
of reducing the odour nuisance had been tried. No known method
could eliminate the stench.
”We were aware that the situation was completely precarious
and that we had to do something. If not, we could expect authority
interference” - says Head of Laboratory, Lene Lange Andersen,
from Skjern Papirfabrik.
”During that phase, we had to be unconventional. We knew
that it was possible to reduce the odour nuisance by adding
oxygen - thus providing better working conditions for the
microbes. We just did not have the system for it.
"Slightly desperate, we accepted an offer from Landia
to try to aerate the tank contents by means of an aeration
system originally designed for wastewater aeration under particularly
difficult conditions. Within a few days, Landia produced and
supplied two pumps with aeration equipment and, since the
design allowed installation in full tanks, we were able to
start right away. Our hands were shaking, but it turned out
to be a success.”
||In short, the system consists of one or more pumps equipped
with so-called ejectors - which look like a Harley Davidson
exhaust pipe - being lowered to the tank bottom. There,
the ejectors blow air along the bottom, thus creating
millions of small air bubbles.
“We began with two aerators and, by the following day, the
stench had been reduced considerably” - says Lene Lange Andersen.
Now, Skjern Papirfabrik has 5 pumps in the same tank and
the odour nuisance problem from the paper mill in the town
of Skjern has completely vanished.
Not only did the aeration system eliminate the stench by
efficient aeration of the tank contents, but, in addition,
it actually brought about some off-spins, which please the
Head of the Environment and Energy Dept. at the paper mill,
Mr Søren Bæk.
“ First of all, the wastewater for our treatment plant has
become cleaner and we do not have to use so much energy for
preparing it for final treatment at the town’s treatment plant.
It was well-timed since the wastewater impact had just been
imposed with new and stronger regulations. It turned out that,
relatively easily, we could treat the wastewater in accordance
with the new requirements.
"Secondly, we could remove the sludge in the tank,
simply by letting one of the aerators point directly
into the part of the tank where the tank contents normally
"I know what I’m talking about, as, in connection
with an earlier tank cleaning, I removed 12 cubic metres
of sludge from the bottom. This is no longer necessary
at all” - says Søren Bæk.
“ It feels good to walk the streets of Skjern again
without being accused of being related to a stinking
"Several of the former complainants now praise
the solution with the Landia aerators.
"Now the people of Skjern can make outdoor barbecues
and hang out their laundry. A smile is much nicer than a sullen
look” - Lene Lange Andersen.