Turning waste into GOLD | Rotorua News | Local News in Rotorua
Turning waste into GOLD
WASTE TO GOLD: Scientists from Rotorua's Crown Research Institute Scion Daniel Gapes and Alison Slade with a desktop prototype of its Waste to Gold project. STEPHEN PARKER 180209SP1
Rotorua ratepayers stand to save $650,000 a year under a ground-breaking environmental project that aims to turn sewage into "gold".
The project, called Waste to Gold, could see sewage sludge that is normally treated with costly ethanol and dumped at the city's landfill instead converted into useful chemicals.
The chemicals include acetic acid (that gives vinegar its sour taste and smell) and has numerous industrial and manufacturing uses, and methane to make electricity.
The project is a joint venture between Rotorua District Council and Crown Research Institute Scion.
Scientists Daniel Gapes and Alison Slade are part of a team of seven at Scion working on Waste to Gold.
Basically, the sewage sludge is put into a pressure cooker that heats it to between 150C and 200C. Heat, oxygen, pressure and time cause the breakdown of the sludge.
"What we are trying to do is control the process to get useful molecules rather than destroy everything in it," Mr Gapes said.
"The acetic acid produced goes back into the waste treatment process, replacing the ethanol currently used to treat the raw sewage," he said.
Council works manager Peter Dine told The Daily Post that if successful, it could save ratepayers up to $650,000 a year within three years.
"It will certainly ease the burden on ratepayers in the future.
"Urban sewage is a targeted rate and this could protect ratepayers from any future price increases."
Mr Dine said 14 per cent of the Rotorua landfill's annual capacity is taken up by sewage sludge and the Waste to Gold process would also extend the landfill's life.
He said the council currently paid about $250,000 a year for the ethanol used in Rotorua's sewage treatment process and about $400,000 a year in landfill fees.
"They are the immediate benefits from the process," Mr Dine said.
He said an initial cost of $490,000 to set up the project would be easily recouped by future savings. The aim is to have a pilot system in operation at the sewage treatment plant within a year.
Chairwoman of the council's waste management sub-committee, councillor Julie Calnan, said the project was a fabulous opportunity for Rotorua to lead the way in minimising waste.
"It's a win-win situation for everyone involved and an exciting way forward for Rotorua's waste management.
"We are so lucky to have Scion right here and close to all of the sites they need to be.
"If it does what they say it can do the benefits to Rotorua are enormous," Mrs Calnan said.
The council's works committee recently approved a recommendation for an initial contract with Scion for the processing of bio-solids.
The recommendation still needs to be signed off by council and will be put to councillors at the year's first full council meeting tonight.
WHAT IS WASTE TO GOLD?
* Converts bio-waste materials into useful chemicals
* Some of the chemicals produced are acetic acid and methane
*Acetic acid can replace ethanol currently used in Rotorua's sewage treatment process
* A pilot project will be undertaken at the sewage treatment plant on Te Ngae Rd
*It could save $650,000 annually in paying for ethanol and dumping sludge at the landfill
*If successful, a large scale model will be permanently installed
The project, called Waste to Gold, could see sewage sludge that is normally treated with costly ethanol and dumped at the city's landfill instead converted into useful chemicals.
The chemicals include acetic acid (that gives vinegar its sour taste and smell) and has numerous industrial and manufacturing uses, and methane to make electricity.
The project is a joint venture between Rotorua District Council and Crown Research Institute Scion.
Scientists Daniel Gapes and Alison Slade are part of a team of seven at Scion working on Waste to Gold.
Basically, the sewage sludge is put into a pressure cooker that heats it to between 150C and 200C. Heat, oxygen, pressure and time cause the breakdown of the sludge.
"What we are trying to do is control the process to get useful molecules rather than destroy everything in it," Mr Gapes said.
"The acetic acid produced goes back into the waste treatment process, replacing the ethanol currently used to treat the raw sewage," he said.
Council works manager Peter Dine told The Daily Post that if successful, it could save ratepayers up to $650,000 a year within three years.
"It will certainly ease the burden on ratepayers in the future.
"Urban sewage is a targeted rate and this could protect ratepayers from any future price increases."
Mr Dine said 14 per cent of the Rotorua landfill's annual capacity is taken up by sewage sludge and the Waste to Gold process would also extend the landfill's life.
He said the council currently paid about $250,000 a year for the ethanol used in Rotorua's sewage treatment process and about $400,000 a year in landfill fees.
"They are the immediate benefits from the process," Mr Dine said.
He said an initial cost of $490,000 to set up the project would be easily recouped by future savings. The aim is to have a pilot system in operation at the sewage treatment plant within a year.
Chairwoman of the council's waste management sub-committee, councillor Julie Calnan, said the project was a fabulous opportunity for Rotorua to lead the way in minimising waste.
"It's a win-win situation for everyone involved and an exciting way forward for Rotorua's waste management.
"We are so lucky to have Scion right here and close to all of the sites they need to be.
"If it does what they say it can do the benefits to Rotorua are enormous," Mrs Calnan said.
The council's works committee recently approved a recommendation for an initial contract with Scion for the processing of bio-solids.
The recommendation still needs to be signed off by council and will be put to councillors at the year's first full council meeting tonight.
WHAT IS WASTE TO GOLD?
* Converts bio-waste materials into useful chemicals
* Some of the chemicals produced are acetic acid and methane
*Acetic acid can replace ethanol currently used in Rotorua's sewage treatment process
* A pilot project will be undertaken at the sewage treatment plant on Te Ngae Rd
*It could save $650,000 annually in paying for ethanol and dumping sludge at the landfill
*If successful, a large scale model will be permanently installed
Email
Print