Nutrient Extraction from Spent Bedding and Pond Sludge

31 Pages
1 May 0012
Author(s): Robyn Tucker, Mick O'Keefe, Eugene McGahan, Paul Jensen, Prof Damien Batstone

This project investigated emerging technologies for extracting nutrients in piggery manure that converts them to fertiliser type products that will appeal to broadacre farmers. This report includes analysis results and technical review of potential nutrient extraction technologies and a preliminary economic assessment of extraction techniques. While fresh spent beddings are technically suitable to AD with a leach bed, this research was only able to demonstrate a modest positive economic outcome (12.3 years payback) for fresh northern barley bedding. Stockpiled bedding and pond sludge appear not feasible for digestion and nutrient recovery as both unsuitable for AD and the moisture content and chemicals needed for extraction make it uneconomical. Recommends reuse method as direct spreading of spent bedding and sludge.