IWOX® Premium

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Efficient, reliable and cost-effective sewage treatment plant for domestic applications.

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Viltra's IWOX® Premium is a 3-stage sewage treatment plant in a two-tank configuration that uses a biological process to effectively treat sewage. It is a highly efficient, reliable and cost-effective solution to sewage disposal for domestic applications where there is no access to a main sewer.



• Very small footprint

• Manufactured in NI from robust, impact-resistant tank grade polyethylene – unlike alternatives which are prone to cracking if not handled carefully

• Can be tailored to suit individual sites

• Certified for up to 8 people (1200 Litres per day)

• Easily installed due to light weight material

• Quiet in operation 

• Extremely low maintenance and running costs; only one mechanical part (Energy efficient Air Pump – 50-55W)


Key Features

 Only one mechanical part - (Energy efficient Air Pump – 50-55W)

 Strong and secure access covers

One-piece mould with no joints below water line

 Rotationally moulded in tough, durable tank-grade polyethylene for easy and cost-effective installation

 Unique buffer zone technology

Features an external air compressor failure alarm – which can be fitted anywhere on the premises

 2 Year Warranty*

*Blower & Small Parts


Environment Agency Standard

IWOX ® Premium is a two-tank system that has been tested and certified to meet the current Environment Agency standard of 97.5%

BOD removal
Free Delivery
Free Delivery
Free Delivery
Installation Available
Free Delivery
Service contracts available
Free Delivery
Free commissioning
Free Delivery
CE Certified


How it works

The IWOX® Premium sewage treatment plant is based on the activated sludge principle.

Pre-Settlement Tank

The wastewater influent flows straight into the settlement tank. Larger and heavier pieces of waste in the flow will sink to the bottom of the compartment. At least once every year, the presence of these materials has to be checked (sludge judge test). If the water flow from the pre-settlement tank to the oxidation compartment is blocked, these materials have to be removed from the tank.

Oxidation compartment

In the oxidation compartment, purification of waste particles in the wastewater is carried out by bacteria in the activated sludge. Here, Chemical Oxidation Demand pollutants (COD) and Biological Oxidation Demand pollutants (BOD) are removed, and ammonia (NH4) is transformed into nitrate (NO3). The oxidation compartment also features a tube diffuser which provides the water with continuous airflow. A desired oxygen concentration (minimum of 1.5 mg O2/l) can be created with the adjustment of a valve.

Final Settlement Area (Clarifier compartment)            

Water and suspended solids are separated here. In the clarifier compartment, the activated sludge that has formed and settled on the bottom is returned to the aerobic compartment, thus achieving a more efficient pollutants removal. The circulation is performed by an airlift pump, which increases the system power efficiency. Once the pollution removal is achieved, the treated water (effluent) is discharged via the outlet pipe. 

Why choose a Viltra sewage treatment plant?

• Custom designed and manufactured in Northern Ireland.

• Fully comprehensive mechanical and electrical installation with technical support from design through to installation and final commissioning.

• Viltra has a team of dedicated and skilled engineers with over 35 years' combined experience.

• Proven track record of supplying cost-effective wastewater treatment systems within the waste water market.

• High quality products and services tailor-made to our customers’ requirements.

• Dedicated after-sales service to give our customers complete peace of mind.

• 24 hour emergency breakdown service only a phone call away.

• Our products are tested and certified to EN12566-3 European Standards.


Country Specific Measures


Call us today to speak to our experts about Viltra's IWOX® Premium sewage treatment plant

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