In this thesis, different studies were performed to investigate the combination of FO for the pre-concentration of municipal WW with an anaerobic membrane bioreactor (AnMBR) for the production of biogas. Firstly, a lab-scale AnMBR was operated for 11 months treating synthetic WW that mimicked the concentrate from a FO process treating municipal WW with 80% water recovery and evaluating the effect of seasonal temperature variation. The second chapter investigated for the first time at a pilot scale, the feasibility of concentrating real raw municipal WW using a submerged plate and frame FO module to reach 70% water recovery. In the third and last chapter, FO and AD technologies were coupled to compare the anaerobic treatment of municipal WW and that of concentrated WW, biogas production and pharmaceutical active compounds removal.