Apparatus for treating wastewater and a system for collecting and treating wastewater combining rainwater drainage

The present invention relates to an apparatus for collecting and treating wastewater based on biodegradation-recombination-biodegration process, comprising: a shell, the space inside the shell is divided into a first chamber and a second chamber by a divider wall, wherein: the first chamber contains biological medium suitable for heterotrophic microorganisms growth; the second chamber contains biological medium suitable for autotrophic microorganisms and heterotrophic microorganisms growth. The present invention also relates to a system for collecting and treating wastewater combining rainwater drainage used for building, comprising: at least one wastewater treatment apparatus above; an indoor pipe system for collecting and transferring wastewater, rainwater comprising a main vertical pipe, substantially horizontal branch pipes; and an outdoor pipe system for transferring wastewater combining rainwater drainage comprising a horizontal pipe for connecting the indoor pipe system for collecting and transferring wastewater, rainwater to at least one wastewater treatment apparatus above