There's Energy And Profits In Sewage

Research underway in Christchurch is making sure we get the best out of our wastewater by finding ways to extract energy from it.

Study leader, Paul Heveldt said overseas work shows that most wastewater treatment plants, both domestic and industrial, could become self-sufficient in energy production using their wastewater discharges.

"It is possible that New Zealand wastewater could become a way to make an extra profit for businesses," said Dr Heveldt.

"Contaminated water is treated before being discharged into streams, rivers or the sea. What is not widely appreciated, however, is that the wastewater itself has a substantial energy content.

"Methane gas can be generated from the wastewater in a process known as digestion and this gas can be collected and used as a fuel to produce electricity.

"This process is already being undertaken at a few New Zealand treatment plant sites and is used elsewhere around the world."

The research, an investment of the Foundation for Research, Science and Technology, is exploring the energy requirements for wastewater treatment in New Zealand and the total energy content inherent in our wastewater.

New Zealand wastewater treatment plants include those that collect and treat the domestic sewage as well as systems at large industrial sites.

A further aim of the study is to educate wastewater treatment managers on the energy potential of their resource.

"Currently, most treatment plants simply accept that energy inputs are necessary to reach a desired high quality result for the effluent that is discharged to the sea or streams", says Dr Heveldt.

"They try to be as energy-efficient as possible, and that's admirable, but they are unaware of the major energy content that could be extracted from the wastewater resource itself."

For further information:

Dr Paul Heveldt, Project Manager, Montgomery Watson Christchurch. Tel 03 343 8751 Mobile 021 891164 paul.heveldt@mw.com

Madeleine Setchell Communications Adviser Foundation for Research, Science and Technology PO Box 12-240, Wellington Tel 04 9177806 Mobile 025 40 60 40 www.frst.govt.nz

© Scoop Media