sterilizer 70 by one of known methods for example by chlorination or ozonization and forms pure water therefore the treatment of the settled domestic sewage in the above system results in pure water that can be used by the consumer in addition utilization of the heat of the treated domestic sewage from aerator 50 as well as of heat of steam from the drying disinfecting apparatus 90 reduces the consumption of fuel required for the functioning of the system the second flow is formed by mixing the sediment from settler 10 and the sediment from low pressure separator 20 this flow is introduced in methane tank 80 gas fuel containing mostly methane gas and solids are formed in methane tank 80 during the biochemical treatment of the mixture containing sediments from settler 10 and low pressure separator 20 gas fuel is introduced into outlet 82 and then into gas storage tank 120 solids from methane tank 80 are mixed with solids from ultrafilter 60 and introduced into the drying disinfecting apparatus 90 by heating up to a temperature between 175 u00b0 f 210 u00b0 f this mixture of the sediments is disinfected and changed into fertilizer dry powder of the fertilizer is packed before shipping steam from pipe 2 is introduced into recuperator 160 in recuperator 160 steam is condensed and the formed condensate is introduced into pipe 2 1 for mixing with the effluent domestic sewage before it is channeled into sterilizer 70 heat from the condensation of steam is used for.