抄録
Changes in water quality with degradation of gray water under anaerobic and aerobic condition were investigated by batch incubation at 20°C. Degradation rate of dissolved organic carbon (DOC) in gray water under anaerobic condition was smaller than that under aerobic condition even with inoculation of anaerobic bacteria. Concentration of dissolved nitrogen (D-N), ammonium nitrogen (NH4-N), nitrate+nitrite (NOx-N) and dissolved phosphorus (D-P) in gray water with inoculation under aerobic condition decreased clearly in six hours from the start of incubation. Concentration of DOC, D-N, NH4-N and D-P in gray water without filtration and inoculation under aerobic condition decreased gradually in a day from the start of incubation. Decrease rates of DOC and total organic carbon (TOC) were expressed by first order equcation. Decrease rate of D-N was expressed by Monod equcation. Decrease rate of NOx-N was influenced by its own concentration and DO concentration. The decrease rate of NOx-N was suppressed under high DO concentration. Relationship between decrease rate of D-P and concentration of D-P was not clear.
