Test of an Extensive System Combining Screen, Vermifilter, Macrophyte Lagoons, and Constructed Wetlands to Recover Nutrients from Fresh Manureand Recycle Water for Flushing in PigHousing
Résumé
Flushing of fresh liquid manure avoids storage of slurry in animal houses and has been developed for a better control of pathogens, odour, and polluting gas emitted by the manure. Treatment of the diluted manure is necessary to recycle the water. A treatment system has been designed for pig housing on slatted-floor. The treatment includes a screen, a vermifilter, a settling tank, macrophytes ponds, and constructed wetlands. The last lagoon is used also as a storage tank in order to regulate inter-seasonal flows to permit water recycling. Research was carried out study on separated experimental systems in order to built a demonstration plant with two aims: (i) a better understanding of the system, (ii) design parameters of abatement and by-product production for technical and economical optimisations. The whole treatment results in an effluent suitable for flushing, where 95% of the COD and nitrogen, over 70% of the phosphorus and potassium, and 99.99% of pathogenic micro-organisms were removed.