Residual solids removal process

Residual Solids

De-watering of residual solids

Clearfleau’s systems are designed to minimise production of residual solids, and to capture the nutrients in solid residues that can be used as soil improvers or composting feedstocks. These are de-watered on site and the small quantity of residual solids produced can be land applied or sent to a composting facility.

One of the key advantages of anaerobic treatment on food and industrial sites, compared with more conventional aerobic systems (either on site or at the local sewage plant) is the reduced output of residual solids.  The effluent load is reduced on site (by at least 95%) and the post digestion residues contain solids that have a nutrient content that can be land applied (subject to the digestate quality protocol - PAS 110).

Dewatering, to increase dry matter, can reduce haulage costs by up to 80%. Clearfleau has access to several dewatering technologies that produce a cake (up to 18% dry matter) that is easy to haul away or land apply (as a soil improver). Other features of these systems include:

  • Self contained skid mounted units that can fit into a confined space
  • Ease of installation, commissioning and operation with low running costs
  • Low energy demand for on-site dewatering (and thickening) applications

Clearfleau is also working on membrane based solids removal systems.  The membranes can either be used for pre-digestion thickening or operated post digestion to produce the solids cake.  The membrane system design is being developed for applications in the dairy sector both for de-watering and also pre-treatment of effluents.   This approach will enhance the effectivness of Clearfleau’s AD system for lower strength effluents.

The appropriate solids de-watering system will be specified by Clearfleau, depending on the site or application required and the nature of the solids to be dewatered.

For more information and to arrange a site visit, please call 0844 477 6292 or email

Residual Solids

Residual Solids

Residual Solids