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8/93 Activated
Carbon For Pure Water
by Werner rev 4/08
Published
in Water Gardening Magazine Nov/Dec 2002 Overview Activated carbon,
(a.k.a.Lignite) is produced from
a soft,
brownish-black coal in which the alteration of vegetable matter has
proceeded further than in peat but not as far as in bituminous coal. Also
called brown coal, is the best choice for ponds, organic molecule (pesticides) and color
removal, due to
it's large pore
size. Lignite has the added advantage of being one of the softer Activated
Carbons, which enables you to grind off most of the bio-film accumulated, by kneading the
bag during routine filter cleaning. You can also reduce the accumulated bio-film
by drying or boiling the A/C. If used in a bead filter, the scrubbing action will expose new surface area
during backwash.
The large pore size is important, because the organics in a pond environment will clog and render ineffective,
the smaller-pored, coconut shell and other carbons. 6 Grams of this type of
Lignite Activated
Carbon has the surface area of a football field. Our
4 decades of experience and testing have shown other Activated Carbons, i.e. pelletized, processed, to be almost useless for pond water, but excellent for
Chlorine and Heavy metal removal in
clear water applications such as swimming pools or drinking water.
Whole
House Filter Cartridge -- Available at most home centers, they are well
suited for de-chlorinating tap water for household use. They fall short,
however, when filling a Pond. They simply cannot keep up with the water flow
from a garden hose. For this reason we cannot recommend them for pond
applications.
Whole
House Activated Carbon Filters--Available
from plumbing supply houses, ranging in price from $400.00 to over
$1000.00 these filters can be used for filling ponds, most have a capacity of
250,000 to 800,000 gallons, some have optional backwash controls for sediment evacuation.
Replacing your Activated Carbon
Checking your water meter just before
installation can give you an idea when to replace the cartridge or the
carbon. Manufacturers will write the cartridge capacity on the cartridge
itself. Bulk applications of Activated Lignite Carbon 1cu ft. of carbon will
de-chlorinate 100,000 gallons of clear water.
Coconut
Shell Carbon
(Small Pores) will remove Chlorine in seconds and can be used
successfully for de-chlorinating city water and other clear water applications
that don't contain dissolved organic compounds,
but is not be the first choice for recirculating pond applications, due to it's fine and
very prone to clogging pore structure.
Cost
Lignite
type Activated Carbon can be purchased on the internet for as little as
$2.50lb in 40lb bags. If you purchase Activated Carbon in smaller
packages, be prepared to spend more. Make sure the Activated Carbon is
dry, some unscrupulous Manufactrers add water to increase the weight.
Pond
Water Application
of Lignite Activated Carbon
Dosage--
For routine maintenance- 1pound (dry) per 1000gallons -replace in 6 months.
For
known problems i.e. pesticides, soap, detergents etc.--3lbs(dry) per 1000gallons--replace in
1 month.
I
never wash my new activated carbon, as I believe the Carbon dust is an excellent
adsorber and will polish the water initially in it's dust form.
The best container is a pressurized solid container with a dedicated
pump. Lacking a pressurized
container, the Activated Carbon can be suspended under a waterfall or even
placed in a stream or filter using a mesh bag, or in a pinch, pantyhose. Make
sure you rinse and knead the Activated Carbon when you clean your filter to keep water flowing
through, instead of around the Activated Carbon. Kneading the activated carbon will remove
much of the bio-film and expose new surfaces,
prolonging the life of the product and should be part of your regular scheduled
filter maintenance.
Contact
Time--
A minimum of five minutes up to one hour depending on the organic content.
Recommended flow is 2 gallons per minute.
Activated Carbon is
less effective at high water temperatures and high PH.
Regeneration--Activated
Carbon can only be regenerated by high heat (900-1600 degrees F. ,certain acids
and steam) and is therefore, not economically feasible to recharge. It
should be discarded after 6 months of normal use, earlier if used to
adsorb heavy known concentrations of pollutants.
Adsorption is
a process that occurs when a gas or liquid
solute accumulates on the surface of a solid or a liquid (adsorbent),
forming a molecular or atomic film (the
adsorbate).
It is different from
absorption, in which a substance diffuses into a liquid or solid to form a
solution. The term
sorption
encompasses both processes, while
desorption
is the reverse process.
How
well the adsorption process works, depends on the time in the water (and
the pollutant), how much water is passing through, how many pores on the
carbon, the concentration of the pollutant and the solubility and molecular
weight of the compound being removed. De-Absorption properties of Activated
Carbon have no bearing on pond water management. The industrial process used to
de-adsorb metals is a chemical process that will never happen in a pond.
Note--A/C
cannot adsorb Ammonia, Nitrite or Nitrates, but the surface area of A/C is so
large bacterial colonies will be formed after 28 days or so and will convert these
substances by the nitrification process.
Activated Carbon
Adsorption in Alphabetical order.
High to very
good adsorption on:
Antimony, Arsenic
(Treated wood Leaches Arsenic into the Water), Bismuth, Bleach, Chloramines(
Chlorine only, see Zeolites for Ammonia adsorption),
Chlorine, Chromium, Colors, Dyes, Gold, Hydrogen Peroxide, Insecticides,
Monochloramine,
Odors i.e. Sulphur, Pesticides, Phenols, Tin, Trihalomethanes.
Good to Moderate
adsorption on:
Acetic acid,
Cobalt, Detergents, Dissolved Organic
Compounds (DOC), Hydrogen Sulfide, Mercury, Ozone, Potassium Permanganate,
Silver, Soap, Solvents, Vinegar, Zirconium.
Fair
adsorption on:
Copper
( If Complexed), Iron(as FE 3+), Lead, Nickel, Titanium, Vanadium.
Low to no adsorption on:
Alkalinity, Ammonia (See Zeolite
), Barium, Beryllium, Cadmium, Carbon Dioxide, Copper,
Hardness, Iron(as FE 2+), Lime, Manganese, Molybdenum, Nitrates, Selenium,
Tungsten, Zinc.
Here's
another adsorption chart:
| 0 - |
Not an application for AC |
| 1 - |
POOR not recommended use |
| 2 - |
FAIR limited application |
| 3 - |
GOOD very acceptable results |
| 4 - |
VERY GOOD a proven application |
| 5 - |
EXCELLENT a proven application |
|
AC - Activated
Carbon is one of the most powerful and efficient methods for
improving water quality. The table shows many of the
problems that are addressed by AC. Keep in mind that with
municipally treated water it is highly unlikely that the majority
of these contaminants will be present. Chlorine (and its
derivatives), is the primary concern. THM's & PCB's may also
be a concern. As shown, \AC is excellent at treating these
problems. |
| Acetaldehde |
4 |
| Acetic Acid |
3 |
| Acetone |
4 |
| Alcohols |
4 |
| Alkalinity |
1 |
| Amines |
3 |
| Ammonia |
1 |
| Amyl Acetate |
5 |
| Amyl Alcohol |
5 |
| Antifreeze |
4 |
| Arsenic |
1 |
| Benzene |
5 |
| Bleach |
5 |
| Boron |
1 |
| Butyl Alcohol |
5 |
| Butyl Acetate |
5 |
| Calcium
Hypochlorite |
5 |
| Carbon Dioxide |
0 |
| Chloral |
5 |
| Chloramine |
4 |
| Chloroform |
5 |
| Chlorine |
5 |
| Chlorobenzene |
5 |
| Chlorophenol |
5 |
| Chlorophyll |
4 |
| Citric Acid |
4 |
| Cresol |
5 |
| Defoliants |
5 |
| Detergents |
3 |
| Diesel Fuel |
5 |
| Dyes |
5 |
|
| Emulsions |
2 |
| Ethyl Acetate |
5 |
| Ethyl Acrylate |
5 |
| Ethyl Alcohol |
4 |
| Ethyl Amine |
4 |
| Ethyl Chloride |
4 |
| Etyl Ether |
4 |
| Fertilizers |
1 |
| Flourides |
2 |
| Formaldehyde |
2 |
| Gasoline |
5 |
| Glycols |
5 |
| Hardness |
0 |
| Heavy Metals |
3 |
| Herbicides |
5 |
| Hydrogen Bromide |
2 |
| Hydrogen
Chloride |
1 |
| Hydrogen
Flouride |
1 |
| Hydrogen Iodide |
2 |
| Hydrogen
Peroxide |
5 |
| Hydrogen
Selenide |
3 |
| Hydrogen Sulfide |
3 |
| Hypochlorous
Acid |
5 |
| Inorganic Acids |
1 |
| Inorganic
Chemicals |
1 |
| Insecticides |
5 |
| Iodine |
5 |
| Isopropyl
Acetate |
5 |
| Isopropyl
Alcohol |
5 |
| Ketones |
5 |
| Lactic Acid |
4 |
|
| Lead |
3 |
| Lime |
0 |
| Mercaptans |
4 |
| Metal Salts |
1 |
| Methyl Acetate |
4 |
| Methyl Alcohol |
4 |
| Methyl Bromide |
5 |
| Methyl Chloride |
4 |
| Methyl Ethyl
Ketone |
5 |
| Naptha |
5 |
| Nitrates |
0 |
| Nitric Acid |
3 |
| Nitrobenzene |
5 |
| Nitroluene |
5 |
| Odors (general) |
5 |
| Oil - dissolved |
5 |
| Oil - Suspended |
2 |
| Organic Acids |
4 |
| Organic Esters |
5 |
| Organic Salts |
4 |
| Oxalic Acid |
5 |
| Oxygen |
5 |
| Ozone |
4 |
| PCB's |
5 |
| Pesticides |
5 |
| Phenol |
5 |
| Phosphates |
0 |
| Plastic Taste |
5 |
| Plating Wastes |
3 |
| Potassium
Permanganate |
4 |
| Precipitated
Iron |
2 |
|
| Precipitated
Sulfur |
2 |
| Propioc Acid |
4 |
| Propionaldehyde |
3 |
| Propyl Acetate |
4 |
| Propyl Alcohol |
4 |
| Propyl Chloride |
4 |
| Radon |
4 |
| Rubber Hose
Taste |
5 |
| Sea Water |
1 |
| Sediment |
2 |
| Soap |
3 |
| Sodium
Hypochlorite |
5 |
| Soluble Iron |
2 |
| Solvents |
4 |
| Sulferic Acid |
1 |
| Sulphonated Oils |
4 |
| Suspended Matter |
2 |
| Tannins |
4 |
| Tar Emulsion |
4 |
| Tartaric Acid |
4 |
| Taste (DI Water) |
4 |
| Taste (From
Organics) |
4 |
| THM's |
5 |
| Toluene |
5 |
| Toluidine |
5 |
| Trichlorethylene |
5 |
| Turpentine |
5 |
| Urine |
2 |
| Vinegar |
3 |
| Xanthophyll |
4 |
| Xylene |
5 |
|
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Guest
Editorials
I would like to publicly say,
without reservation, that everything I write or say about activated carbon was
learned from Werner of Werner's Water Gardens.
All I did was to try to help Werner to explain it to the ponding public by
publishing my own experiences using it. Everything else came from Werner.
My other comment is that Sue wrote the article by editing Werner's comments to
this board, with a few of mine, then sent it to Werner and myself to make sure
she had edited it correctly. So Sue did a great job on the article as editor.
Roddy Conrad
Charleston, WV
"Have a pleasant day"
Hello Werner,
I enjoyed you article on activated carbon
in the pond. A little F.Y.I. on lignite carbon. Lignite activated
carbon is not a wood-based carbon. It is a true coal based product.
Lignite coal is mined from the ground like other coals. We are the
largest lignite carbon supplier to the aquarium industry and the only
supplier of lignite carbon to the pond market. We also sell peat-based
(also a coal product) and bituminous coal activated carbon. The lignite
coal is superior in ponds due to the unique pore structure and
adsorption properties.
I wish more folks would use activated
carbon in the pond. It can really work wonders in improving water
quality and color removal.
Best regards!
James Layton
Aquatic Biologist
Aquarium Pharmaceuticals, Inc.
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:
http://www.marineland.com/articles/17RevisActCarb.html
http://www.alcoholpurification.com/recycling_with_steam.html
http://www.ext.nodak.edu/extpubs/h2oqual/watsys/ae1029w.htm
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