|
1) How long will it take before the
sludge is dry enough to haul off?
2) How do I determine how many Geotube® containers
I need for my plant or my project?
3) What happens if I fill the Geotube® container
higher than the design height?
4) Can I dewater municipal wastewater
treatment biosolids without using polymer?
5) Can Geotube® technology
dewater and contain secondary sludge?
6) Can Geotube® technology
dewater and contain primary sludge?
7) What is the main reason to use
Geotube®
technology?
8) Can Geotube® containers
contain contaminated material such as PCBs?
9) How do I find out if Geotube® containers
s are right for our needs?
10) Can Geotube®
dewater and contain Alum sludge?
11) Can Geotube® containers
dewater and contain fly ash?
1) How long will it take before the sludge is dry
enough to haul off?
There are several factors that influence the time it
takes to sufficiently dewater sludge:
1. Chemical conditioning is the key to optimum
dewatering. Working with a polymer supplier, bench
tests are conducted to determine the best polymer
for dewatering the sludge. Once the product is
chosen, the dose is determined. Overdosing the
polymer can cause the sludge to “hold onto” the
water rather than releasing it and may result in
blinding off the Geotube® geotextile.
Properly mixing the polymer into the sludge is also
important. The polymer should be made down into a
lower percentage solution and ideally, aged for 30
minutes before injecting it into the sludge line.
Equally important is to provide enough mixing
in-line to assure that the polymer attaches to the
sludge particles to create a floc and allow the free
water to flow out of the Geotube® containers.
2. Type of sludge or age of sludge can influence how
fast it will dewater. Well digested sludge will
dewater more quickly than raw sludge.
As process water sludge will dry faster than
biosolids.
3. The longer a client can allow the sludge to
remain on site and dry after the final filling
cycle, the drier the solids will become and the
greater volume reduction will be achieved.
top
2) How do I determine how many Geotube® containers
I need for my plant or my project?
First we gather the following information:
1) Volume of sludge or flow rate of residuals to be
dewatered.
2) Specific gravity of the solids.
3) In situ percent solids.
4) Percent solids during dredging or pumping.
5) Target percent solids after dewatering.
6) Production rates, GPM, hours per day and
efficiency of pumping or dredging.
7) We begin by doing bench tests to determine the
appropriate chemical conditioning. Tests are then
conducted to determine volume reduction and target
cake solids after dewatering with Geotube® containers.
The tests may be a Rapid Dewatering Test (RDT), a
hanging bag test, a full-scale test or a combination
of two or more of these tests. Samples of dewatered
sludge are taken at intervals and dried to determine
percent solids by weight.
8) This information is put into a spreadsheet
designed to determine the linear footage of various
circumference Geotube® containers required to
accommodate the volume of sludge.
top
3) What happens if I fill the Geotube® container
higher than the design height?
Geotube® container design height is
controlled by the tensile strength of the textile
with a 4:1 factor of safety. Exceeding the design
height could result in the textile rupturing.
top
4) Can I dewater municipal wastewater treatment
biosolids without using polymer?
Yes, but the capture of solids won’t be as efficient
and it will take much longer to get sufficiently dry
cake solids. There is also a risk of masking off the
pores of the textile. We
recommend the use of polymer on most sludges.
top
5) Can Geotube® technology dewater and contain
secondary sludge?
Yes, It will probably require a polymer to assist in
flocculation. This will result in very clean
filtrate and solids comparable to older mechanical
dewatering technology.
top
6) Can Geotube® technology dewater and contain
primary sludge?
Yes, most installations use a polymer to assist in
dewatering allowing faster refilling and obtaining
finished solids sooner. Solids levels are usually
equal or higher than the traditional older
mechanical methods.
top
7) What is the main reason to use Geotube® technology?
Economic savings have been realized by every
customer using Geotube® technology
over traditional dewatering, remediation processes.
top
8) Can Geotube® technology contain contaminated
material such as PCBs?
Yes, Geotube® technology has been
chosen by both governmental agencies and private
companies as the leading way to safely contain most
contaminants, especially PCBs. Getubes®
also provide the added protection of aerating
contaminants when processed through an older
technology of mechanical methods. Economic reasons
are again a key factor.
top
9) How do I find out if Geotube® containers are
right for our needs?
Contact a Geotube® representative
to discuss your goals and objectives. Experiences
with similar applications may already exist that can
answer your questions. If not, we normally start
with a bench trial (RDT) to determine if there is a
good chance of success. Then a hanging bag trial can
be performed using about 40 to 50 gallons of the
material for each bag to help provide estimated
chemical needs, dewatering rates, filtrate
concentrations, etc. In a few applications a full
size Geotube® container is installed as a pilot study.
top
10) Can Geotube® technology dewater and contain Alum
sludge?
Yes, It will probably require a polymer to assist in
flocculation. This will result in very clean
filtrate and solids comparable to older mechanical
dewatering technology.
top
11) Can Geotube® technology dewater and contain fly
ash?
Yes, It may need a polymer to assist in flocculation
is the ash is very fine and light such as wood ash.
Most coal fly ash has dewatered without polymers to
very high solids.
top |
