Assessment of the workings of a pig slurry treatment facility on the farm with phase separation and anaerobic lagooning

Abstract

An assessement of waste elements from a piggery producing nearly 11000 growing pigs per year and their transformation before landspreading was determined on slurry subjected to centrifugal sieving and storage in an anaerobic lagoon. This effluent contains 3.77, 1.31 and 1.44 kg of N, P and K, respectively and 30 and 76 g of Cu and Zn per growing pig produced. Ammonia volatilization accounts for 28 % of excreted nitrogen: 11 % from the piggery and 17 % from the lagoon. The estimated methane emissions from the lagoon were between 4.9 and 5.9 kg per pig produced. After decantation in the lagoon, 82 % of the rejected P, Cu and Zn, 32 % DCO and 13.8 % of excreted N, can be collected in a manageable sediment after drying on a sand bed. The transformations in the lagoon produce a partially purified liquid that is easier to use than the initial manure. The purifying system can be further improved.