Waste water recycling

Sherpa Engineering has partnered with EDF Optimal Solutions, Firmus and MRI and established a consortium with the objective of developing and installing a water recycling solution for waste water (or grey water). The recycling system provides water and energy savings and has an advanced control system incorporated for water and energy optimization.

Thanks to this system the recycled water is used for showers, cooking, washing and cleaning. We obtain a recycling rate of up to 80% and the quality is regularly monitored. Water quality after recycling is excellent and even close to drinking water. Additionally, no pollution was found during the observing period.

We use a global approach during the system installation life cycle. We aim at optimizing the total cost of ownership (acquisition cost and water and energy expenses). Thanks to our systemic analysis and our simulation tool we are in the position to define the optimal system and to operate it according to usage needs. Consequently we can validate the solution and estimate costs prior to installation.

System description

The system is made of 4 independent subsystems:

  • Supervision system for water/energy optimization
    This subsystem has been developed by Sherpa Engineering. It is based on model-based predictive techniques and allows selecting the best control strategy according to the customer profile and the environment. We target at cost reduction during the whole product life cycle (operation and maintenance) and eco-efficiency. Economical evaluation is calculated through simulation. The purpose of this simulation sub-system is to provide data for cost analysis and the optimal design of the system.
  • Recycling water and treatment system
    This subsystem is called FGWRS (Firmus Grey Water Recycle System) and has been developed by Firmus Company. It consists in collecting grey water from showers, washing, cooking and condensation, stocking and treating it afterwards. Not all grey water is recycled, but only a part of it and the rest is sent to the sewer system. FGWRS is composed of several membranes of nano-filtration(NF), ultrafiltration(UF) and inverse osmose (IO)

  • Energy optimization system
    EDF Optimal Solutions brings to the consortium a solution for energy recovery after recycling grey water from FWGRS pumps. The energy obtained is used for hot water production (55 to 65C) and cold water production (10 to 15C) thanks to heat pumps. EDF Optima is in charge of integrating the solution inside the building.
  • Water quality monitoring system
    The complete solution requires quality control and monitoring processes adapted to regulation. MRI is an expert company in regulation issues.