Digestate is the main residual product from biogas plants. The liquid fraction obtained in the decanter is fed to the tubular MBR, where organic matter and nutrients are removed by combining anoxic and aerobic reactors. The external tubular modules coupled to the biological process produce a free-of-solids permeate that can be pos-treated with reverse osmosis. The effluent is therefore discharged, fulfilling the strictest environmental regulations, or it can be reused for irrigation or other industrial purposes.