Abstract
A nitrification reaction by nitrifying bacteria has remarkably exerted the influence in the measurement method of present BOD according to the design and the operation condition of facilities though the quality of effluent in domestic wastewater treatment facilities has been evaluated by before disinfection in johkasou and after disinfection in public sewerage systems. Moreover, the examination of the influence evaluation of the chlorine disinfection is not necessarily done enough. In this study, we examined the quality of effluent in operating johkasous before and after disinfection for the appropriate and efficient promotion of domestic wastewater measures to protect regional aquatic environments. The investigation was executed for 85 small johkasous which had been installed in the separate houses in prefecture of KANTO area. As a result, the rate of BOD fitting to an expected performance reached 92% after disinfecting 79% whole before disinfected, and the effect of the BOD removal in the disinfection tank was admitted. In the evaluation of the effect of the environmental load-reducing the final effluent on the destination from this, it was showed that it was appropriate intended for the quality of effluent after disinfected, and there were few significant differences concerning the treatment performance with public sewerage systems.
