‘Wetland in a box’ cleans up at awards

Gerald Piddock TECHNOLOGY Fieldays

AFILTRATION system designed to remove freshwater contaminants may become another tool farmers and communities can use to improve water quality in New Zealand’s rivers and lakes.

Created by eClean Biotech, the system uses a bioreactor housed within a large structure similar to a container to filter out contaminants, specifically nitrates, E coli and heavy metals from farm drains, rivers streams, bores and dams.

The bioreactor and its housing can also be custom designed to suit the requirements of a particular waterway, eClean

Biotech creator Ngārie Scartozzi said.

“It’s like a wetland in a box.”

The invention was recognised at this year’s Fieldays, winning the Early Stage Award at the Innovation Awards.

Scartozzi said eClean Biotech’s potential as an environmental tool is exciting.

“We believe this could be another good tool that the dairy industry could use.”

Scartozzi spent three years researching and developing the technology in the laboratory and it took just under a year to commercialise it.

It was created in partnership with Hugo Plastics, which developed the tank design and housing for the bioreactor.

It has two systems that have been trialled in operation in

Christchurch for the past 18 months, with support and funding from the Christchurch City Council.

Two more systems are also to be installed, in Hinds in MidCanterbury, on farmland that uses the Managed Aquifer Recharge irrigation system for further trials.

It is a fast-acting treatment. Water is pumped into the system and travels through a series of baffles and is aerated. Microbes within a bioreactor eat the contaminants and the clean water is returned to the waterway.

“Basically, the technology removes up to 80% of nitrates, 50% E coli and 50% heavy metals first pass,” Scartozzi said.

“At the moment we can do on a single system 2L a second. We’re going up to 17-20L a second, which is like a million litres a day.”

A residue sludge is left over, containing high levels of nutrients that can be used as fertiliser.

The entire process takes around 45 minutes, she said.

“It’s got a really small footprint and we control everything inside the system.”

Intellectual property reasons prevent Scartozzi from revealing more about the microbes used in the process. She said they use a range of microbes, which are combined and customised depending on the contaminant profile of the waterway.

It is not designed to act as a filter for wastewater from an effluent pond but as a filtration system once contaminants have entered waterways, she said.

Scartozzi sees it being used in settings where there is a community or a group of irrigators that want to improve the district’s water quality, or if a farmer has a series of drains or waterways on their farm and wishes to remove nitrates from the water.

“We can quantify how much nitrates they are removing per day, per kilogram and per tonne per year.”

The technology also has potential in aquaculture, where it could also be used for land-based fish farming to maintain water quality.

On a farm, the ideal place to put the system would be downstream close to where a waterway connects to a tributary so it can capture as much of the contaminants as possible.

In a large water body, such as a lake, a series of systems could be placed on its parameter to help reduce contamination.