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Cleaner water the Waikato way

Cleaner water the Waikato way
Waikato scientists have come up with a novel method of purifying water while simultaneously disinfecting it against microbial contamination, which is now being developed for residential, commercial, horticultural and agricultural use.

Waikato scientists have come up with a novel method of purifying water while simultaneously disinfecting it against microbial contamination, which is now being developed for residential, commercial, horticultural and agricultural use. 

Dr Hilary Nath (left) and Associate Professor Alan Langdon with their PEFT cell

Dr Hilary Nath (left) and Associate Professor Alan Langdon with their PEFT cell

The electrochemical perforated electric flow-through (PEFT) cell technology came out of University of Waikato, drawing on 10 years of academic research under Associate Professor Alan Langdon and the more recent doctoral research of Dr Hilary Nath. 

With the support of WaikatoLink, the university’s commercialisation company, they are working with two New Zealand businesses to make prototypes and are seeking partnerships with companies that have water quality issues with iron and manganese and/or microbial contamination. 

The PEFT technology applies a low voltage current to water to remove contaminants. The water is then forced through a perforated electrode system and  a combination of oxidation, coagulation and precipitation eliminate elements such as iron, manganese, arsenic and micro-organisms. This is brought about by the generation of chlorine from naturally occurring chloride ions present in water and the high electric fields produced by the cell.

A prototype will be on show at Fieldays later this month.

The PEFT technology has big export potential in countries with arsenic and other contaminants in their water supplies, according to WaikatoLink general commercial manager Nigel Slaughter.

But for now the focus is on providing clean rural domestic drinking water, later scaling up to animal watering.

"Our research indicates there is a good market opportunity for a low cost water purification platform that is a compelling alternative to existing solutions.”

Jessica King, WaikatoLink commercial manager, says the PEFT technology has a number of advantages over some existing solutions, which can be bulky, expensive and maintenance-heavy.

“While other electrochemical systems can provide chlorine on demand for water treatment purposes, they operate as offline devices using concentrated brine solutions and require specialised metering devices.  Our system also minimises the risk of harmful byproducts forming that can result from standard chlorination."

Research innovation network KiwiNet supported the project with a $92,500 investment from its PreSeed Accelerator Fund from the Ministry of Science and Innovation, which was matched by WaikatoLink.