Laboratory investigation of supported permeable organic covers for the management of odour emissions from anaerobic piggery waste ponds

Australian research has linked much of the odour arising from intensive liv estock operations to pond treatment systems. A reduction in emissions from treatment ponds would therefore generally reduce odour emissions from inten sive livestock operations. Published data indicates that the application of straw and other biological materials to effluent pond surfaces as a contin uous cover reduces odour. emissions. The effectiveness of these covers has not, however, been researched under controlled conditions. Using locally av ailable materials, the efficacy of supported covers has been investigated u sing a series of laboratory anaerobic digesters treating typical piggery ef fluent. Research to date has focused on: identifying effective cover and cover support materials; quantifying odour reduction; identifying the impact use these covers may have on greenhouse gas emission s; devising practical and effective methods for constructing these covers. Results have confirmed that a variety of cover materials are effective in r educing pond occur emissions. Supporting the pond cover appears to extend t he cover life expectancy. While greenhouse gas emissions appear to vary acc ording to cover type, the overall significance of these emissions is not ye t clear. The impact of permeable pond covers on overall pond performance re quires additional research.