sewage treatment plants

Package treatment plants

Read more about package treatment plants available in the UK as well as Tricel Novo sewage treatment plant.

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sewage treatment plants

Package Treatment Plant


Definition of a Sewage Treatment plant

A sewage treatment plant is intended primarily for individual homes and businesses (package treatment plant) which are not connected to a mains sewer. It works on the same principle as the collective purification plants, but in a miniaturized version for individual use.

The owners of wastewater treatment plants must follow the “Small Sewage discharges in England: General Binding Rules” as issued by the Department of the Environment, Food and Rural Affairs. Different rules apply for sewage treatment systems in Northern Ireland, Scotland and Wales.

If you require further information about the Tricel Novo

The diverse types of sewage treatment plants

The Sewage treatment plants are divided into two large families

  1. With free bacterial culture
  2. With a culture fixed on a support

1. Free cultures: two technologies are available.

On the one hand, there is the  “classic” activated sludge sewage treatment plant, and on the other, a more technically developed version, the SBR.

  • Activated sludge: is the most common solution in package treatment. This technology is generally based on a tank with two compartments only, one for aeration and treatment and the other for settling and clarification.

This is the least efficient of the solutions compared to the two other technologies presented below because it generates more sludge and does not support the variations of loads.


  • SBR (Sequencing Batch Reactor): sludge is suspended in the sewage treatment plant, usually in a single tank. The effluents will be treated thanks to a complex electronic system which activates the distinct phases of treatment intermittently to allow the oxygenation of the effluents:
  1. The decantation: the separation of the sludge and heavy solids from the effluents.
  2. The clarification: the effluents are clearer thanks to the deposition of residual pollution at the bottom of the tank.
  3. The evacuation: the treated wastewater is now discharged to surface water.

2. Fixed bed: sewage treatment plants with fixed bed do not normally include any electronics. A compressor sends air into the treatment compartment, which a diffuser transforms into micro-bubbles to oxygenate the effluents. Bacteria that attach and grow on the bacterial bed use this oxygen to degrade the pollution contained in the effluents.

How a Tricel Novo plant is working?

The operation of a waste water treatment, more commonly known as a sewage treatment plant, is based on a biological process. Micro-organisms, naturally present in the wastewater of the house, will feed on the organic pollution they contain and thus degrade it by developing. To do this, some of these bacteria need oxygen.

The wastewater treatment process is broken down into stages:

  1. The primary settling: during this phase, the sludge and the heaviest solids are deposited at the bottom. The effluents are thus rid of most of their pollution before proceeding to the second phase of the treatment. This step is not always taken up in free crop operation, and it is altered for SBR stations that combine the first and second stages into one.
  2. Aeration: this phase makes it possible to feed the bacteria with oxygen. The means employed vary from one type of sewage treatment plant to another. As a rule, airing is done by means of the air supply of a compressor accompanied by a diffuser. The bacteria thus have the oxygen molecules necessary for the biological degradation of the pollution.
  3. Final settling and clarification: during this stage, residual sludge, denser than water, will settle at the bottom of the tank. This allows a final separation between water and residual pollution. The water treated is then in compliance with the standards of rejection in force and can be evacuated from the tank to the natural environment.

Advantages and disadvantages of a Tricel Novo plant

Like any equipment, package treatment plant systems have advantages and disadvantages. They could be summarised as follows:


  • Compact: about five m² of floor space (for five or six population equivalents);
  • Lightweight: (200 to 300 kg): easy and inexpensive installation (sewage treatment plant with concrete tank weigh more than two tons);
  • Efficient: effective treatment, no risk of clogging;
  • Adaptable: suitable for all types of terrain (difficult ground, the presence of groundwater);
  • Reliable: long life (20 to 40 years, whereas the spreading of a traditional die, must be replaced every 10 to 20 years);
  • Tested and certified: for structural strength, water tightness, durability and treatment efficiency, adhering to European Standard EN12566- 3 (like all sewage treatment solutions manufactured by Tricel).



  • Not suitable for secondary homes
  • Electricity consumption (cost: around £45 per year)
  • Relatively restrictive annual maintenance for some brands of sewage treatment plants

View Tricel Novo manual

Get in touch if you have questions or need further information

Key Features


Strong, lighweight and easy to install SMC tank

Fast delivery

UK manufactured ensuring short lead time


Tricel Novo is certified to EN12566-3

Get in touch

Tricel Environment UK

A trading brand of Dewey Waters Ltd.
Heritage Works, Winterstoke Road, Weston-super-Mare, BS24 9AN, United Kingdom.
Tel: +44 (0)1934 422 311