Rewaise tests anaerobic sewer mining technology

An anaerobic sewer mining technology is being demonstrated by REWAISE that calls attention to the 'end of the pipe' problem.

Testing the concept

REWAISE, a major initiative of four European water utilities dedicated to building a smart water ecosystem, is progressing with the demonstration of its anaerobic sewer mining technology.

Called MEMB-RANER (membrane reactor for anaerobic nutrient and Energy recovery), the solution allows for the conversion of organic matter directly to biomethane, without requiring energy for aeration.

Similar to aerobic membrane bioreactors (MBR), MEMB-RANER uses microfiltration submerged in the treatment tanks to concentrate the biomass, to reach a disinfected effluent free of solids, but rich in nutrients for irrigation.

“It was able to handle a flow of 10 m3/h, which will allow them to establish the exact material balances on the energy recovery and water reuse potential.”

Being a compact and enclosed system, it can be fitted in the basement of a building or a car park to convert local sewage into irrigation water.

Overcoming the 'end of the pipe' problem

Sewer mining, as a concept, aims to help overcome the ‘end of the pipe’ challenge with conventional, centralised treatment.

Treatment plants typically tend to be located far away from the potential users of any available water, energy and fertilises that can be generated from the wastewater.

An alternative approach, decentralised treatment, enables the resources to be generated and kept closer to end-users.

For example, onsite separation systems would allow for the recovery of water in a concentrated stream, giving the ability to reuse greywater in buildings for purposes such as flushing toilets, for example.

Giving LIFE to sewer mining

To test the technology, MEMB-RANER was first piloted in the LIFE MEMORY project. Led by private water company Aqualia, the solution was installed in the car park of the car factory in Vigo, near to the mainline sewer.

It was able to handle a flow of 10 m3/hour, which will allow them to establish the exact material balances on the energy recovery and water reuse potential.

As the operator, Aqualia said it will be able to use the data gathered by the system to offer a more sustainable service to its customers.

The previous LIFE MEMORY project was used to first develop the technology, allowing subsequent REWAISE to scale up the system for industrial use.

Anaerobic systems are gaining interest. Last year, French water management company SAUR acquired a majority share in a Dutch technology company, Econvert, a Water Alliance member that specialises in anaerobic biological processes for industrial wastewater treatment.