Quick Dips

Treating Waste Well

A research team at Victoria University is developing an eco-friendly waste treatment technology that is aimed at improving the treatment of waste effluent from New Zealand dairy sheds and from meat, fish and vegetable processing factories.

The project, which is being carried out by Professor Jim Johnston, Dr Peter Northcote and PhD student Michael Richardson of the School of Chemical and Physical Sciences, aims to make recycling operations more environmentally friendly and cost-effective.

Private sector companies Protein Ventures Ltd and Pure New Zealand Ltd have taken an interest in the technology, are providing some financial support for the research and are involved in the commercialisation of the technology.

"New farming practices, with larger dairy herds and a smaller number of larger processing industries, have led to larger quantities of organic waste being disposed in concentrated areas, to the detriment of the local environment," says Johnston.

However, the technology being developed at Victoria could hold the answer.

"It reduces the waste from these sources to a clear solution of simple organic acids, somewhat like vinegar, substantially reducing the chemical and biological oxygen demands and the impact on the environment."

A pilot waste treatment plant utilising the new technology has been designed and is currently being constructed.

"This plant will be operated at Victoria to test the technology on an industrially meaningful scale, and provide information for the design of a commercial plant," says Johnston.

"Waste disposal is a costly problem for industry, and a number of meat and food processing industries both in New Zealand and offshore are waiting anxiously for the commercial plants to become available."

"Organic waste material in most countries can no longer be dumped on land or in surface waterways. There is a cost to sewage ponds and treatment -- look at what the Wellington City Council had to pay for its new treatment system."

"The cost of disposal is a very real one and any technology that does it better or cheaper provides industry with a competitive advantage. Our technology has this potential," he says.

The new technology has been developed from work done by Johnston and the University of Manchester's Professor Nicholas Wiseman on paper recycling and filler mineral recovery.