System and method for maintaining microbial activity in on-site treatment of runoff sewage

The invention relates to the technical field of non-point source pollution control, and discloses a runoff sewage in-situ treatment microbial activity maintaining system and method.The system is connected with a microbial treatment system and comprises a treatment unit, a first storage unit, a hydrolysis unit, a separation unit and a second storage unit. A large number of particulate pollutants contained in rainwater runoff are fully intercepted through the treatment unit, and the particulate pollutants are further hydrolyzed and acidified into hydrolysate which is easily utilized by microorganisms and contains soluble organic matters and volatile fatty acids in the hydrolysis unit; therefore, the obtained hydrolysate is transmitted to the microbiological treatment system in the dry season so as to maintain the activity of sludge in the microbiological treatment system, and meanwhile, through a hydrolysis mode, not only is the increase of operation cost caused by supplementing a carbon source in the dry seaso