OTHER TECHNOLOGIES
Phosphorus removal
Version :
PHOS-TAB, PHOS-4-FADE
Process :
Passive chemical, Absorption
Energy:
Very low to none
Application :
Residential, Commercial
Phosphorus removal is a crucial step in wastewater treatment when the receiving environment is considered sensitive.
Enviro-STEP Technologies offers three different phosphorus removal solutions, each with its own advantages and applications. Like the rest of our technologies, our dephosphatation solutions are developed with simplicity and performance in mind.
- Liquid chemical dephosphatation unit (DCL)
- Phos-4-Fade passive adsorbent filter
- Phos-TAB passive dephosphatation unit
Operation
LIQUID CHEMICAL DEPHOSPHATATION (LCD)
Our DCL units use the recognized and widely used process of coagulation, flocculation, and settling to remove phosphorus from wastewater. Using a liquid coagulant, a metering pump injects the coagulant into the wastewater to precipitate the phosphorus and convert it from a dissolved form to solids. This is followed by two mixing stages: rapid mixing (coagulation) and slow mixing (flocculation). The solid particles formed trap the phosphorus, which settles by gravity in our settling tank.
DCL units can be used for co-dephosphatation or post-dephosphatation depending on the treatment chain used and the discharge target. In addition, it is possible to configure one or more injection points in order to achieve very low phosphorus levels in the range of 0.5 to 1 mg/l.
Our DCP chemical dephosphatation systems can be delivered complete with a prefabricated coagulant dosing unit, fast and slow mixing tanks, a decanter, and, if necessary, a separate tank for sludge storage. Our engineers provide drawings and calculations to support consultants.
Performance
Our DCL liquid chemical dephosphatation units can achieve different levels of phosphorus in the effluent depending on the number of injection points.
- 1 injection point: 0.8 to 1 mg/l
- 2 injection points: 0.5 to 0.8 mg/l
How PHOS-TAB works
PHOS-TAB uses the recognized and proven principle of chemical dephosphatation by dosing aluminum sulfate. However, instead of using a liquid coagulant, PHOS-TAB uses a solid coagulant in tablet form, making the process entirely passive with no need for electricity. PHOS-TAB is the logical choice for low-flow applications or seasonal sites where dephosphatization is required only part of the year.
The effluent flows by gravity into a dissolution unit where solid alum tablets dissolve slowly and gradually, releasing the metal ions needed for phosphorus coagulation. The integrated weir ensures dissolution proportional to the flow rate by varying the dissolution rate according to the water level in the contact chamber. The coagulated water flows to the decanter, which has a piston flow flocculation device in its inlet area, allowing slow mixing to promote floc agglutination. The chemical sludge formed settles and remains trapped in the decanter, which is emptied periodically. The decanter has an advanced inclined tube settling device that optimizes solids capture and ensures stable performance. PHOS-TAB can be used when the required phosphorus standard is 1 mg/l in the effluent.
PHOS-TAB Performance
Domestic wastewater treated at a secondary or advanced secondary level and directed to PHOS-TAB will have its phosphorus content reduced to 1 mg/L or less.
PHOS-TAB has a technical data sheet issued by the MELCCFP and the BNQ and is considered a conventional process.
Settings
PHOS-TAB effluent (after settling)
Total phosphorus (mg/L)
N/A
MES (mg/L)
≤ 15
Total phosphorus (mg/L)
≤ 1
pH
6,0 ≤ pH ≤ 9,5
How PHOS-4-FADE works
PHOS-4-FADE, offered exclusively in combination with our HYDRO-KINETIC product, is based on the physical principle of adsorption and is one of the only dephosphatation products on the market that does not use chemicals. PHOS-4-FADE is completely passive and contains no mechanical or electrical components.
The principle of adsorption is based on the natural magnetic attraction of phosphorus to the filter media that makes up PHOS-4-FADE.
The service life of the PHOS-4-FADE filter depends on the flow rate and phosphorus concentration of the wastewater. In typical residential domestic water applications, several PHOS-4-FADE filters have achieved a service life of up to 10 years before needing to be replaced. When necessary, the filter is vacuumed out and replaced with a new one.
PHOS-4-FADE performance
When used in combination with the HYDRO-KINETIC system, PHOS-4-FADE is capable of achieving phosphorus concentrations of 0.3 to 1 mg/l.
Settings
Standard requirement
NQ 3680-910
(BNQ classes)
Hydro-Kinetic
+ PHOS-4-FADE
(Class IV)
Hydro-Kinetic
+ PHOS-4-FADE
+ UV AT-1500
(classe IV & V)
DBO₅C (mg/L)
15
3
3
MES (mg/L)
15
2
2
Fecal coliforms
(CFU/100 mL)
50 000 (III & IV)
200 (V)
2 900
2
Total phosphorus
(mg/L)
1
0.14
0.14
Phos-4-Fade is certified according to BNQ 3680-910 and CAN/BNQ 3680-600 standards.
Your questions, our answers
Why should I install a PHOS-TAB?
Do PHOS-TABE tablets last a long time?
In general, a full refill lasts one year for normal residential use. Consumption depends directly on your water usage: the more water you use, the faster the tablets dissolve.
Does Phos-TAB require electricity?
No, that's one of its great advantages. It's a gravity-fed, passive system. It even works during power outages, unlike some liquid injection phosphate removal systems that require electric dosing pumps.
PHOS-4FADE: What is the main difference between this and PHOS-TAB?
PHOS-4-FADE is designed for higher flow rates or higher phosphorus loads. Its pellet tank is often larger, allowing for greater autonomy and better management of flow variations (such as during receptions or for large families).
PHOS-4-FADE: Why is it considered a “passive” system?
Because it requires no dosing pump, no electronic sensors, and no electricity to inject the chemical. Dissolution occurs naturally upon contact with water, making the system extremely reliable in the event of a power failure and reducing the risk of mechanical failure.