TenCate Geotube RDT Guia De Inicio Rapido página 5

Step 4
Fill a 500ml beaker with the sludge to be tested.
Determine a starting point for the polymer dosage in
PPM and draw the required amount of polymer into
a syringe. Example: Start with 40 PPM. If this
dosage creates a good floc, test a lower dosage
until the optimum dose is determined. A chart of
dosages is available from TenCate TM . Add the
polymer solution to the 500ml of sludge and begin to
pour the sample back and forth between the two
beakers until a floc forms.
Step 5
Slowly pour the 500ml of conditioned sludge into
the RDT funnel.
Step 6
Using a stopwatch, time the free water flow
through the funnel. Record the effluent volume at
30-second intervals up to 5 minutes.
Step 7
Examine the filtrate for clarity and suspended
solids. Remove the RDT from the beaker, and
unscrew the top of the funnel.
Slowly remove the Geotube ® GT500 fabric from the
plastic funnel and collect the dewatered sludge.
Examine how the cake releases from the fabric.
Repeat this procedure for all the candidate
polymers to determine the most efficient polymer
in terms of time to dewater, volume of filtrate, and
clarity of filtrate.
Step 8
Collect a sample of dewatered sludge. Conduct a
moisture content test to determine percent
dewatered solids.
DEWATERING: RDT TEST I 5