Biological Treatment

Biological wastewater treatment is another stage in the treatment process and happens after larger particles have been removed through the filtering or settlement stages of the process and is necessary when a high quality of effluent is required.

Biological wastewater treatment is an effective way of breaking down and eliminating organic waste, typical of the waste products produced in the food and drink and chemical industries.

Viltra offer a wide range of solutions for effective biological treatment that can be tailor made and designed specifically for any application.

Activated Sludge

An activated sludge process is a multi-chamber reactor unit that makes use of highly concentrated microorganisms to degrade organics and remove nutrients from wastewater to produce a high-quality effluent. To maintain aerobic conditions and to keep the activated sludge suspended, a continuous and well-timed supply of oxygen is required. It consists of flocs of bacteria, which are suspended and mixed with wastewater in an aerated tank.

SAF (Submerged Aerated Filter)

Submerged Aerated Filters (SAF) are a well-proven technology for wastewater treatment. The SAF process uses single cells inside the tank which are assembled in series, the wastewater flows through each chamber in sequence.

Each cell includes a media on which biomass forms and a fine bubble diffuser system feeds oxygen from blowers in the control kiosk to promote the growth of the biomass.

A blower sends air to the bottom of the bed to provide oxygen for the biomass to support the oxidation process. The air stream encourages both efficient mixing of the effluent and disturbance of any excess solids from the filter medium.


Moving bed biofilm reactor (MBBR) is a biological technology used for wastewater treatment process suitable for municipal and industrial applications. Another common name is moving bed film reactor.

MBBR wastewater treatment system enables efficient results of the disposal using low energy. The technology is used to separate organic substances, nitrification and denitrification. MBBR design is made of an activated sludge aeration system. The sludge is collected on the plastic carriers which have a large internal surface area. The surface area in the carriers optimises the contact of water, air, and the bacteria.


Membrane technology is a wastewater treatment process in which membranes are used as filter elements. Membranes permit water to pass through them while preserving suspended solids and other substances. The Membrane Bioreactors (MBR) combine biological processes and membrane technology being an activated sludge treatment whose secondary decanter is replaced by a system for separating solids and liquids using membranes.

MBR systems can reduce extremely high-strength sewage streams such as that produced by food processing, dairy and breweries to meet the most stringent environmental standards.

Our latest projects

A wastewater solution designed and installed with the utmost care for a unique 18th-century National Trust property in Northern Ireland

A bespoke concrete wastewater solution for one of the most protected RSPB nature sites in Britain, with some of Scotland’s most amazing wildlife

A drip distribution system and upgrade works to a sewage treatment plant for a large Nursing Home

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At Viltra, we are specialists in separating waste and water. Whether you have an individual household, a business or a development, we all need and rely on water, we all create and dispose of waste and we all must keep these two worlds apart.

Viltra are a dedicated team who designs, manufactures and installs wastewater treatment solutions for a wide range of sectors across the UK and Ireland, including the commercial and industrial sector, education sector, conservation sector, domestic sector, agricultural sector and the tourism and hospitality industry. Offering an end-to-end service, the experienced team at Viltra ensure our customers receive a premium service and a robust solution to their wastewater management requirements.

To make an enquiry or to book a site visit by our expert engineers who will find a solution for you, please get in touch with Viltra through the contact form provided.

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