Whey to biogas

Massey University and Palmerston North City Council have found a way to increase the production of biogas to help drive the council's cogeneration engine to produce steam and electricity.

Laboratory trials at Massey have shown that previously unwanted whey, a by-product of milk processsing, can be mixed "co-digested" with sludge from the Totara Road Treatment Plan.

Now a full scale trial is under way at the wastewater plant to develop a cheap method of disposing of whey, increase gas production from the city's digesters and ultimately earn more carbon credits.

"If it proves to be successful - and indications are positive - it could become a permanent addition to the wastewater treatment process," council water and waste services manager Chris Pepper said.