Evaluation of Phanerochaete chrysosporium for swine wastewater treatment

The swine slurry is a mixture of manure, urine, and cleaning water from pig livestock farms, characterized by its high chemical oxygen demand (COD) and ammonia concentration. This effluent needs to be treated before being spilled to avoid negative environmental impacts as eutrophication of surface water reservoirs. In this study, an untreated slurry and two pig slurries pre-treated by anaerobic digestion with and without ammonia trapping were treated biologically by Phanerochaete chrysosporium. The effect on the biological treatment of pre-treating the raw slurry by sieving and centrifugation was evaluated. Samples were inoculated with 3 g/L (dry matter) of fungus and incubated at 26 C during 10 days in a batch reactor. The activity of ligninolytic enzymes (LiP, MnP and Lac), colour, COD, total nitrogen and BOD5 evolution during the treatment were analysed. For undigested slurries, the best results were obtained for sieved slurry, reaching removal efficiencies for soluble COD and colour around 68% and 78%, respectively. For digested effluents, the digestate coming from the reactor with ammonia trapping membrane showed the best results with efficiencies of 38% for soluble COD and 35% for colour. These results provide new insights into the application of this fungus as complementary method to treat swine wastewaters.