The essence of the innovative concept in this project is the recovery of suspended solids from raw wastewater on the basis of particle size. In comparison to common solids separation on the basis of density, the positive impact on downstream processes is significant. An existing finescreen technology is adapted and optimized for this new application.

In various pilots in different European countries the technology is tested and at one location in The Netherlands, the technology is installed on a small demonstration scale. In this project we will apply the concept for the first time full-scale at WWTP Aarle Rixtel in The Netherlands.


Compared to the current state of the art solutions this concept has a number of significant advantages with an enormous impact:

  • Reduction of the volume of sludge that has to be transported, and thus a very strong reduction of transport movements. Projected on the case of Aarle Rixtel (272,000 people equivalents), the transport volume would decrease by approximately 24%.
  • Significant reduction of chemical requirements of the WWTP. For WWTP Aarle Rixtel the polyelectrolyte consumption will be reduced with approximately 30%, which equals 9,000 kg/year with an associated cost reduction of € 58,500/year.
  • Reduction of aeration energy (approximately 15%) because of the reduced load to the biological treatment process. For Aarle Rixtel this means 677.950 kWh or € 88,000/year.
  • Increased biogas production potential (approximately 36%) as a result of the high organic content of the separated and dewatered solids. For the full-scale Aarle Rixtel application the additional biogas potential is 295,500 m3 biogas/year or € 45,000/year. If the technology would be applied at 10% of specific biological WWTPs in Europe these values would raise to 44 mln m3 additional biogas potential per year or € 6,822,667/year.
  • Smaller WWTP footprint of approximately 25%.

In spite of the advantages mentioned, realization of a first full-scale installation is critical for a successful market introduction and widespread implementation, because:

  • Local governments and exploitants of WWTPs tend to be conservative (risk aversive), meaning that they prefer to buy proven technologies;
  • Due to a shift in tender procedures, a part of the operational risks are the responsibility of the contractor, which makes them reluctant to apply new technology.

The interest of the market is huge, given the number of case studies already carried out. Various consultants have executed case studies for at least 30 Dutch WWTPs and over 25 other European sites.

Supported by a network of European partners, a lean consortium consisting of a technology developer (BWA), a launching customer (Waterboard Aa & Maas) and a knowledge institute (KWR) highly experienced in leading European projects, wants to achieve a first full-scale reference. With a sufficiently validated full-scale reference the concept will be further applied in Europe and beyond.

screencap-tekeningBased on a conservative estimate of the European market, it is expected that the technology is potentially interesting for at least 9000 WWTPs. Main Screencap objectives therefore are 1) First full-scale validated application of the finescreen technology as a pre-treatment on a biological WWTP and 2) Overcoming market barriers for uptake of the concept and technology in Europe and beyond.