The paper presents preliminary experimental results which aim to demonstrate the possibility of producing easily biodegradable carbon from a two phase anaerobic digestion process for a biological nutrient removal process. Crystallization of phosphorus into struvite from the liquor of the digested flow is the second goal of the process studied. With this integrated process approach it is possible to double the amount of readily biodegradable COD entering the wastewater works by sewers and to recover up to 70% of phosphorus from the digested flow as struvite without using little amount of chemicals. Struvite granules are useful for agricultural purposes.