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ACTING FOR AN EFFICIENT STORM WATER MANAGEMENT

SUSPENDED SOLIDS : MAIN CAUSE OF STORM WATER POLLUTION

When falling on the ground, a heavy rain will wash and will erode surfaces. It can carry visible pollutants but also micro-particles of different sizes. Organic and chemical pollutants can also be carried by the water : there are called Suspended Solids (SS).
The real impact of pollution from SS comes from their ability to concentrate micro-pollutants on their own surface (process called adsorption) and to carry them in the stormwater ﬂow.

MICRO-POLLUTANTS: DANGEROUS, EVEN IN SMALL AMOUNT

A micro-pollutant is an undesirable particule and very difﬁ cult to detect in the environment (mg per litre or even nanogramme per litre). Some micro-pollutants comes from human activities (industrial processes,farming or daily activities).
Toxicity and presence of micro-pollutants in the environment have negative effects on living organisms.

Micro-pollutants have several chemical properties. It can be:

→ mineral micro-pollutants such as metals, non-metals and radioactive elements: cadmium, mercury, arsenic, antimony, radon,
uranium, etc.

→ organic micro-pollutants such as pesticides, hydrocarbons, solvents, detergents, cosmetics, medicinal substances, etc.

The European Regulation has identiﬁed over 110,000 molecules of organic micro-pollutants.

THE ORIGIN OF STORM WATER POLLUTION

Examples of pollution : combustion residue of heat engines, fuel additive, oil leak, tyre and brake wear, catalytic converter wear, bodywork and chassis corrosion, ﬂ oor painting, cement, bitumen, asphalt, building materials, soil erosion, incinerators

BIOMETISM, A NATURAL INSPIRATION TO DEVELOP FUTURE TECHNOLOGIES

By following the nature and its innate know-how, Techneau has successfully developed a new generation of compact pollutant-interceptor, able to trap and to store micro-suspended solids (SS).

DECANTEAU’ UNIQUE TECHNOLOGY IS BASED ON FOUR SPECIFICITIES:

→ A giratory circulation of the ﬂ ow resulting in a signiﬁ cant improvement of
the settlement period therefore also improving the decantation process;
→ Redentations, generating recirculation zones speciﬁ cally designed to
optimize the agglomeration of particles;
→ Guide nozzles ensuring constant ﬂ ow distribution & water speed control;
→ A sludge tank isolated from the water ﬂ ow in order to trap all sediments.

AN OPTIMIZED INTERCEPTION PROCESS OF SS *

THANKS TO A DOWNWARD DOUBLE SPIRAL FLOW TRAJECTORY

The DECANT’EAU is composed of a  spreader head and a sludge tank. 
This unique design, resulting from 36 months of research & development, is a perfect combination of multiple innovations and enable most SS to be trapped, whatever their dimensions.

The efﬁciency of the Decant’eau process is based on a double spiral ﬂow trajectory :

>The gyratory circulation of the ﬂow around the central 
column, allowing to extend the SS settling time and to ease their decantation process.
> The recirculation zones, generated by guiding nozzles 
that structures the head, optimise the agglomeration of all particles and ease their decantation process.

A UNIQUE AND PATENTED FLOW DISTRIBUTION PROCESS

GUIDING NOZZLES SPECIFICALLY DESIGNED TO HOMOGENIZE THE WATER FLOW

One of the many strength of the Decant’Eau is the ﬂ ow
distribution in the lower part of the diffuser head,
through guiding nozzles.

These guiding nozzles allow to equally separate the water
ﬂ ow from SS, insulating them by orientation to the device
walls.
This ﬂow distribution keep a central discharge shaft clean
from all polutants. Meanwhile, the water ﬂ ow natutally
bring particles towards the outlet.
The sludge silo stores the sediments away from the
passing ﬂ ow thus avoiding their re-suspension.

A LARGE STORAGE CAPACITY OF BOTH MUD AND PARTICLES

ISOLATED FROM THE PASSING FLOW

The sludge silo, fully isolated from the top part of the device, trap muds and particles from the passing ﬂow,hence avoiding their re-suspension in case of heavy rainfall.

Its large storage capacity minimizes the frequency
of maintenance.

INTERCEPTION OF POLLUTANTS AND FLOATABLES

→ In case of accidental release of hydrocarbons or ﬂoatables gross elements (plastic bags, bottles,masks etc…) the DECANT’EAU has enough storage capacity to avoid a direct release to the outlet without treatment.

→ In case of accidental release of hydrocarbons, the device can
momentarily store a volume of 300 litres (the equivalent of 6 full tank).

TOTAL CONTROL IN CASE OF EXPCEPTIONAL STORM WATER FLOW

→ In case of heavy rainfall the DECANTEAU is able to handle the
peak ﬂ ow thanks to the discharge shaft.

→ The discharge shaft is designed to afford high peak ﬂ ows, while
being completely isolated fromall ﬂoatables and muds.

FROM STANDARD TO TAILOR-MADE

BOTH POLYETHYLENE AND POLYESTER DEVICES ARE AVAILABLE

→ The polyester is the perfect material for adjusting the height according the water inlet. It can also be adapted to perfectly ﬁ t any storage capacity.

A COMPACT AND VERTICAL DEVICE FOR AN EASY INSTALLATION

The DECANT’EAU comes fully equipped, ready to be installed.

The installation, identical to our other works
An easy installation process due to the vertical shape of the very light Decant’eau device.

The polyethylene version allows to limit the transportation cost and the installation time thanks to its weight lighter than the concrete.

Therefore, No need for an heavy lifting device.

No corrosion : the PE material ensures a longer life time than steel or concrete.

EASY TO MAINTAIN, EASY TO CONTROL

No ﬁlters, no substrats are needed to operate the DECANT’EAU.
The large sludge tank is easy to access through the discharge shaft. This unique feature allows a signiﬁ cant saving on maintenance fees.

Download our Decant’eau brochure :