Lincoln University scientists develop methane emission reduction technology

Professor Hong Di (left), Emeritus Professor Keith Cameron and Ravensdown's Carl Ahlfeld. Photo / Ravensdown

Lincoln University scientists have developed an effluent pond treatment that they say reduces methane emissions by up to 99 per cent.

EcoPond, the new treatment system, also slashes the amount of E.coli in the treated effluent, reduces ammonia emissions, mitigates odour and cuts phosphate leaching losses from effluent areas into waterways by up to 90 per cent.

EcoPond was developed by Emeritus Professor Keith Cameron and Professor Hong Di in partnership with Ravensdown and launched to market on Wednesday, November 10.

The system works by adding iron sulphate - a safe additive used in the treatment of drinking water - to effluent ponds.

Cameron and Di hoped Ecopond's greenhouse gas mitigation would be a game-changer for dairy farmers.

Cutting greenhouse gas methane emissions has been a focal point of the recent COP26 climate summit in Glasgow, with New Zealand joining more than 100 countries pledging to reduce them by 30 per cent over the next decade.

Nearly all dairy farms used effluent ponds, which were the second-largest source of on-farm methane emissions, after cow belching, Cameron said.

"Our development and demonstration of the new system, undertaken at the Lincoln University Research Dairy Farm, has proven that the new system is enormously effective at neutralising the methane-producing process, resulting in a 4 to 5 per cent reduction in an average dairy farm's overall methane emissions."

EcoPond can be easily retrofitted into a farmer's existing effluent system, Cameron said.

EcoPond's efficacy in reducing greenhouse gas emissions was discovered during the development phase of Lincoln University's ClearTech system, Di said.

"In testing the ClearTech system for unintended consequences we found that the gases we collected off the effluent in experimental set-ups indicated a reduction in methane emissions of greater than 90 per cent.

"In science, it's rare to achieve such a large influence on an experiment."

Encouraged by this finding, the scientists tested the system using farm-sized effluent storage tanks.

"The result exceeded our wildest hopes, achieving a methane emission reduction of 99.9 per cent," Di said.

We're still working on that last 0.1 per cent. We'll get there!"