|
| |
Links found on this page -
acid cycle , acid discharge ,
acid run off , coastal regions ,
Calibrated Flood Gate Valve ,
calcium carbonate ,
CRAB , eco-system ,
environmental ,
sulfidic muds & soils
Active Lime Dosing
This is a technique that essentially copies what is happening in the
tidal drains, substituting salt water management for artificial dosing
techniques and is especially useful in highly polluted acidic effluent with low
pH and high levels of dissolved aluminium and iron.
Using the CRAB to manipulate pH with a blend of lime reagents.
The pH reading is 7.93.
Key Benefits
 |
Instead of using salt water to flocculate metal loads and subsequently
producing 'sulfidic ooze' the salt water is substituted with
calcium carbonate
or some suitable alkaline reagent. |
|
The result of using calcium carbonate is the production of calcium
sulphate commonly known as gypsum and iron and aluminum hydroxides.
These by-products can then be recycled as a useful product beneficial to soil structure
and at pH above 5 the metal hydroxides will rapidly absorb further heavy
metals. |
Some of the reagents that
can be
accurately dispensed are -
|
Calcium carbonate - rock form |
|
Calcium hydroxide - 600kg bags or 25kg bags |
Capabilities
The process would involve making an artificial pond either by
|
damming, |
|
weiring existing drainage systems or, by
|
|
building a complete sump and diverting effluent water through the
sump. |
Accurately treating the effluent water with alkaline reagents and therefore
raising the pH to 7, much of the heavy metal can be 'dropped out' in the sump,
and in fact, the 'buffering' capacity can be added, in the form of excess carbonate
to the water discharging from the sump.
The sump design would look something like this -
                                                           
| The question is often asked what to do with the sump once it is full.
The best possible thing to do is to monitor the depth of sediment build up and
at a stage close to full capacity 95% dig another sump using the treated over
burden to 'cap' the existing sump and continue with land use. |
|
 |
| Incidentally there are examples of this process already working.
|
| A small sediment catchment weir servicing a soft rock quarry in
Northern NSW on a creek containing large loads of iron and aluminum. This dam is now full and is
growing grass and rain forest trees on top of the mass. Had this sump been treated
with calcium carbonate the mass would have remained quite stable for future
use. As it is, it runs the risk of failure and subsequent re-oxidation of
contained sulfidic mass therefore once again completing the acid cycle. (see
photos above) |
-
Contact Information
- Telephone
-
ACID
-
Sales & Enquiries - 1800 11 2243
- Service - (61)
0439 38 48 84
-
- Postal address
-
- Acid Solutions Pty Ltd
-
-
-
PO Box 3040
-
Currumbin
-
Qld 4223
-
- AUSTRALIA
-
- E - mail
-
- Information:
acidsolutions@bigpond.com
|
