A fast take on wastewater
0.45 seconds is not a lot of time to make a lasting first impression, but for a Palmerston North hi-tech start-up it’s part of the appeal.
That’s how long it takes dirty water, travelling at 6.7 litres a second, to pass through Novolabs’ UV treatment system and come out clean.
Its patented Supercritical UV process, which can disinfect a thin layer of low quality wastewater at high speed, is turning heads, and it has the potential to have a huge impact on the environment and municipal infrastructure. “We’re small, but the global potential is just massive,” said Novolabs founder Andrew Shilton, a professor of environmental engineering who devised and developed the technology at Massey University.
What had been a two-person operation working out of a Massey shed, where a tarpaulin had to be hung to stop birds in the rafters pooping on them, was now a six-person team with its own building in a Milson industrial park.
The innovation, a modular chamber that could be stacked and fitted inside shipping containers, had led to Novolabs being a finalist in four categories at the New Zealand Hi-Tech Awards, including hi-tech startup company of the year, and best solution towards a sustainable future.
While ultra-violet light was already a conventional method for sanitising drinking water and wastewater, where the Supercritical system stood out was its ability to treat low clarity liquids other systems couldn’t and without the use of chemicals.
The effectiveness of UV light treatment on pathogens in water degraded exponentially as the water deepened or its quality worsened.
Shilton said traditional systems weren’t effective below 30% UV transmittance (UVT) - the amount of ultra-violet light able to pass through the water sample.
Supercritical UV treated water channelled at an extremely thin layer, 4mm to 6mm deep, for high penetration, easily destroying algae and bacteria at 25% UVT, and in some applications at under 1%.
“All over New Zealand, just about every small community, you’ve got wastewater and environment, and the only thing you’ve got in between is an algal pond,” he said.
“And again, algae get in the way of the light, they’ll block the light. So it doesn’t take very much algae and you don’t have a good disinfectant solution.
“But we can eat those. Absolutely, that’s so easy for this system.”
Supercritical UV was also more economic than alternative technologies that included high amounts of chemicals that also carried a larger carbon footprint.
Novolabs chief executive Matthew Sells showed Manawatū Standard a module being prepared by chief engineer Mark Kiely for a rural community of about 500 people in Ahipara, Northland.
Their wastewater went to an algal pond, where algae would break down organic matter and nutrients. Algae bacteria consumed the organics and nutrients, but there was still a lot of E.coli that would pass into a constructed wetland, and then a freshwater stream.
Supercritical UV could clean the water without the need for chemicals to first eradicate the algae for increased water clarity.
The one-module system was costing just under $100,000, but the client could be looking at $2 million or an alternative system that required chemicals.
A meatworks in Gisborne using the system had 26 million units of E.coli per 100ml of wastewater flowing into the modules.
This was reducing to eight units at the outflow, just 0.45 seconds later. The consented level was 800 units.
The modular nature of the system meant communities or companies could add on as they grew, and if one module required servicing it could be stopped without interrupting the others.
Each rack could clean 5 million litres a day, with a stack of 10 cleaning 50 million litres a day in the space of a freight container.
Business development manager Jordan Shilton said there was a lot of potential for the technology to be applied to municipal wastewater, with small towns under pressure to improve their wastewater.
“I think it’s a really awesome opportunity for these smaller councils who are really struggling. It’s hard when you’ve got a small ratepayer base, to do big capital upgrades.
“And when central government is telling you you need to get up to spec, you just don’t have the budget for it.
“It’s a solution where you can stop people getting sick basically.”