Turning water into wine
A new system for dealing with effluent and wastewater could have significant benefits for the wine and dairy industries.
It uses a cyclonic filter to remove solids from wastewater, which is then clean enough to be reused for irrigation.
It was developed by Christchurch-based research company Scott Biotechnologies for use in the dairy industry and installed on its first farm last year but is likely to prove as popular with winemakers as farmers.
Scott Biotechnology principal Ken Scott said he spent two years developing the system, which collects wastewater from the milking shed and passes it through the cyclonic filter. This separates the solid waste, mostly lignum (woody material) and cellulose fibres, from the water, which is then clean enough to be fed into the farm's irrigation system.
The vortex created in the filter also oxygenates the water, which neutralises odours.
Scott is having the cyclonic filters at the heart of the system manufactured to his specifications in the United States, and the rest of the components are manufactured by Ashburton-based Rainer Irrigation, which distributes and installs the complete system.
Rainer general manager Gavin Briggs said his company had tried using other wastewater filtering systems but they had proved unreliable.
"There were other products on the market that we installed for dairying but they basically wore out," he said.
"So I stopped putting that equipment in and pulled out of the market because there were so many issues with it."
Briggs said he had heard of cyclonic filters being used in the oil industry to remove clay from oil but the Scott version was the first he was aware of designed for agricultural use.
There were also financial advantages with the Scott system, which on average cost around $25,000 to install, about half the cost of the systems the company previously supplied, Briggs said.
While dairy farmers will see advantages in the system, its application in the wine industry was an unexpected development that came about due to a family connection.
Ken Scott is the brother of winemaker Allan Scott, who immediately saw the potential of his brother's invention for his Marlborough winery.
Allan Scott said a rough rule of thumb was that wineries produced about equal amounts of wine and wastewater during the winemaking process.
Most of the solid waste from grapes was removed early in the process and turned into stock feed or compost but some solids remained in water that was used to flush and clean the equipment.
Many wineries used a series of septic tanks to treat their wastewater but sometimes they were not up to the job because the industry produced most of its wastewater in a short burst following the annual harvest, meaning the treatment system had to cope with a lot of water in a relatively short space of time.
"These days the councils and regional authorities are really tough on how this is processed," Allan Scott said.
"I think they've been reasonably tolerant in the past but they've now come down with a heavy hand.
"We've tried different ways of dealing with it but none have been that successful."
Although his brother's system was designed for dairying, it did not need to be modified to be installed at the winery and had worked well, he said.
It was producing clean water, which was then used to irrigate the vineyard.
Allan Scott said that meant he had to draw less groundwater from the vineyard's bores, providing environmental benefits.
The sludge that remained after the wastewater has been filtered could be used as fertiliser.
With the New Zealand wine industry producing more than 250 million litres of wine a year, the impact of the new system on the industry and the environment could be substantial.
"It's one of those things that just works. Often you get a good idea but there are so many drawbacks you wonder if its worthwhile. But this just worked from the start," Ken Scott said.
Sunday Star Times