TECHNOLOGY FOCUS - ENVIRONMENT - Preferred Process: The process (P1) further involves subjecting the liquid fraction to a reverse osmosis step after the biological filtration process. In the process (P1), the porous granules are contained in a bioreactor unit placed in or near the storage tank. The liquid fraction is mixed with the porous granules by pumping the liquid fraction into the bioreactor unit during residence in the storage tank. The mixture is aerated is implemented by aerating the bioreactor unit. Prior to the step of mixing the liquid fraction with the porous granules, the porous granules undergo a culturing process for growing of the bacterial culture on the porous granules. A sample of the liquid fraction of the faeces to be processed is mixed with the porous granules during the culturing process for matching the bacterial culture to be grown with faeces to be processed. The biological decomposition of ammonia is effected by unit of at least one biological process selected from a group comprising an aerobe biological process and an anaerobe biological process. The bacterial culture comprises at least one bacterium selected from the group comprising nitrosomonas and nitrobacter. The storage step involves storing liquid fraction in a storage tank for 1 week to 3 months.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred components: The porous granules is selected from granules of volcanic rock, zeolite granules or montmorillonite granules and porous ceramic granules. The porous granules have a particle size with an average diameter of 10-30 mm.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The unit for mixing the liquid fraction with the porous granules comprises a pump for pumping the liquid fraction from a storage tank into the bioreactor unit. The pump is a submerged pump that is fixed to the bioreactor unit, and the bioreactor unit is arranged for placement in a storage tank for a liquid fraction of human or animal faeces. EXAMPLE - No suitable example given.