Mobile Reedbed Evaluator System
Agricultural
Slurries
Wool Scouring
Electro-Plating
Yes
we even tried lager through the test beds. This was from alcohol confiscated
by customs. I have lost the photo's, but the lager went in and clear water
came out. Now another gentleman turned water into wine. Turning lager into
water does seem to be the wrong way round. Still, that's progress.
Introduction
Initially
funding supported trials throughout Kirklees and Calderdale. More recently
site visits have had to be funded by the company seeking trials. However,
there are companies willing to fund trials.
Methods
Setting
up a trial involves :-
·
transporting the system to site
·
setting up a small flow initially until the system has settled down
·
increasing the flow and taking samples for analysis, usually from week 4
·
continue with flow rate, sampling and analysis for weeks 5 & 6
making any adjustments as necessary
·
following 3 consecutive results a report is written summarizing results
and performance
Reedbeds
either work well ( 85 to 99% reductions ), work alright ( 65 to 68 %
reductions ), or doesn’t work at all ( reductions of 33% or less ). Where they
work well then a full-scale system could be built. Where reductions are 65 to
68% then it is likely that additional chemical pre or post treatment is
required to achieve maximum pollutant reductions.
Results
Each of the following results have been as part of a final report. Only the actual results have been collected for this report.
The
Mobile Reedbed Evaluator System has visited a number of Dye works. The results
are as follows :-
The
results from Brook Dyeing were so good, they wanted to find out how effective
the Reedbeds would be with effluent containing permethryn. The results were as
follows :-
Initially
there were two Mobile Evaluator Systems, and the second system went to
Blackburn & Sutcliffe in Triangle, near Sowerby Bridge
A
65% reduction was all the system could achieve. This was seen as disappointing
at the time. However, current experience suggests that additional pre or post
chemical treatment would help reduce concentrations by the usual 95%.
The
system visited Brisbane Moss on the Todmorden Road, from Hebden Bridge,
Next the system visited Crossley Farm:-
It
was thought that The Environment Agency would know the standard analysis of
farm slurry from the farm, as they had threatened to prosecute if reductions
were not made. However, they had no figures. As such a second trial took place
where analysis of inflow and outflow was made.
Clearly
the initial trial results were confirmed.
The
system then visited Thomas Chadwick, Wool Scourers in Dewsbury. The results
were as follows :-
A
second visit to Chadwick's took place in November, December and January of
2001 to 2002. This visit took the untreated slurry in an attempt to simulate
conditions in Standard Wool's wool scouring factory in Punto Arenas, in
southern Chile.
Initially
in November, effluent inflow levels of COD at times were 70.000 to 80,000
mg/L. The COD for the Chile effluent is normally between 25,000 and 30,000
mg/L.
As
these COD figures were very much higher than those normally found in Chile,
the tests were simply not representative of those we were trying to replicate.
A dilution of the raw effluent was made. As a result, the effluent would be
diluted as 5L raw effluent and 5L water. The results are as listed above from
the date of the 27th November.
These
results are as follows :-
Average
figures for the 50% dilution results only
inflow and outflow levels in mg/L
ENCO
Results
The
results of the ENCO sampling is as follows :-
These
results confirm in greater detail, the results of the COD tests at Thomas
Chadwick’s in Dewsbury. Significant reductions in the levels of COD and
grease have been achieved. The reduction of total solids is not so great, and
does indicate the need for an additional method for further solid reduction.
This additional method could also help reduce suint levels further.
Soil
Samples
Soil
samples from both Reedbed tubs were tested for percentage total grease, at the
beginning and at the end of the trial. These results were as follows:-
These
samples were taken at the inflow sites of both beds. The total area of Reedbed
remained unaffected by grease, except for these small sample points.
The
figures for the 20/11/01, 04/12/01 and 12/12/01 were particularly bad, however
out of the 15 tests, these three ( 20% ) seemed only to be isolated incidents
as the reduction rates for the days following did not seemed to be affected.
Of the figures 80%. show a reduction more than 75%.
The
filtrate remains like tea. Clearly the Reedbeds are filtering all the
components of the effluent that can be reduced by bacteria at these rates of
flow. The reduction of the remaining pollutants would need further
investigation. An additional trial of a flocculent was made to see if further
reductions could be possible.
Flocculent
An
additional trial took place to add a flocculent to the filtrate. The results
were as follows :-
Grosvenor
Chemicals
There
is always a limit to any science. The visit to Grosvenor Chemicals in the
Colne Valley proved this case. The trial was of surface water run-off, which
is collected around the site and pumped to central tanks for discharge to
sewer.
The
company packages herbicides and pesticides. Not surprisingly therefore this
system which depends on the activity of bacteria and plants did not do as well
as hoped.
Iron Ocre is pretty bad stuff. The dissolved oxygen is used up in forming iron oxides, leaving no oxygen for invertebrates and fish in the water. A stream or river becomes virtually lifeless.
The
principle for the Mobile Reedbed Evaluator system was used to construct the
trial beds for the Greens Clough Project. This project provided the greatest
example of human courage and endeavor, when the community people had to
manually carry 6 tons of equipment up the hill at Greens Clough, Todmorden.
They did this bag after bag, hour after hour. This was the finest example of
people willing to make a difference, and of authorities and agencies showing
little value of such a monumental effort.
The
following is a scan of the document, showing the site design, layout, sampling
points and results.
The
rate of flow through the test beds was twice normal expected flow. These
results demonstrate the effectiveness of Reedbeds, high up on the Yorkshire
Pennines. The project was told Reedbeds don't work, there would be no approval
and there certainly would be no funding. We achieved all three. These results allay the initial
fears.
Decorpart
Electroplating, Nelson
The
Company is facing strict disposal limitations. The Mobile Reedbed Evaluator
System was given the opportunity to demonstrate its effectiveness. The results
are as follows :-
The
pre treatment technology has yet to be determined. However, once again
Reedbeds have proven their value in effluent treatment. A trial bed of 100m2
is planned, while the full size needed is 600 m2 .
Currently
the Mobile Evaluator System is at Heinz in Telford. The trial is progressing
at the time of writing ( 18/10/02 ), however results to date are :-
COD IN
COD OUT
% Reduction
*
25,000
1950
92%
*
53,000
2500
95%
Currently
there is interest from Campbell's, Dairy Crest, Kaltech Abattoir Waste.
Summary
Strangely
enough, while the program was funded and companies did not have to contribute,
there was little interest in the amazing results. Since companies have paid
for the site visits of the system, this has led to serious consideration and
planning to install full scale Reedbed Filtration Systems.
While
each visit began more as an adventure, the collective knowledge and
understanding gained has produced a rare, if not unique view of the
effectiveness of Reedbed Filtration, either as stand alone systems or as part
of additional pre or post chemical or biological treatment.
Skepticism
of Reedbeds comes from the comfort of current "normal" treatments
and procedures. However, just as current treatments and procedures have
altered dramatically over the past 10 years, then it is also likely that they
will continue to do so over the next 10 years, and at an increasing rate of
change. In light of the certainty of future change therefore, the need to
consider additional methods of effluent treatment could not be more important
with regard to future costs and official approval for waste effluent
discharge. Water Companies may in future have to refuse to accept certain
discharges to sewer, in order that they meet with stringent water quality
requirements.
Reedbed Filtration is a biological approach, which allows effluent to pass through at a rate, which allows the Reedbed Ecosystem to effectively filter effluent concentrations. The Mobile Reedbed Evaluator System has extended the potential for such treatment throughout many industrial sectors. Industry can now significantly reduce its costs and its environmental impact simultaneously. What remains is the need for the vision, willingness and knowledge to do so.