News, Events and Culture

Sludge eating plant launched in Palmerston North

Tuesday May 28 2013

Funding of $1.1 million from the Government’s Waste Minimisation Fund has enabled Palmerston North to be the first city in the country to pilot an innovative ‘Wetox’ sludge treatment plant.

Wetox is a process which involves applying high pressure and temperature to break sludge down into its various components which can then be recovered as fertilisers and other valuable chemicals.

The Wetox technology was developed at Victoria University of Wellington as part of PhD research carried out in the School of Chemical and Physical Sciences.

Wetox Limited was formed by VicLink, the Victoria University company that commercialises intellectual property.

Based in Wellington, the spin-out company, led by CEO Dr. Kevin McKay, is taking the Wetox technology to market both in New Zealand and in Europe.

The Palmerston North plant has been designed by Fitzroy Engineering based in Auckland and New Plymouth.  Palmerston North firm Etech Engineering Ltd completed the construction and installation.

Professor Neil Quigley, Deputy Vice Chancellor (Research) at Victoria University says the Wetox solution is an outstanding example of how cutting-edge technologies can be created from fundamental research.

"The plant has huge benefits for the City," Palmerston North Mayor Jono Naylor said. "With the introduction of this process, the City is one step closer to meeting its goal of diverting 75 per-cent of its waste from landfills by 2015."

Rob Green, Palmerston North City Council water and waste services manager says one of the chemicals to be recovered from the process is alum which the Council uses at its water and waste treatment plant.

"Our intention would be to reuse the recovered alum on site to reduce the costs of purchasing it," Mr Green said.

"Phosphates will also be recovered by the Wetox process which is great news as it means the chances of phosphates leaching into the Manawatū River from waste water are extremely minimal. We hope to be able to sell the recovered phosphates as fertiliser," Mr Green said.

The process will mean a huge reduction in the amount of sewage sludge going into the landfill.

As with most scientific breakthroughs, says Professor Quigley, the Wetox technology resulted from a collaborative effort with other partners including Callaghan Innovation (formerly Industrial Research Limited) and the Palmerston North City Council.

Geoff Todd, CEO of VicLink says: "Waste water, water treatment and industrial processors that produce sludge face tighter environmental constraints and rising costs of disposal. The Wetox system provides a cost-effective solution to this problem."

Officials and visitors will get a first-hand look at the Wetox plant at the official launch this afternoon at the Totara Road Water and Waste Treatment Plant in Palmerston North.

The pilot scheme has cost the Palmerston North City Council approximately $10,000 for the initial set up.