Study on characteristics and design criteria regarding to inflow rate of wastewater of rural sewerage facility

摘要

The behavior and characteristics of inflow rate of wastewater were investigated using observed data on rural sewerage facilities. The influencing factors on the variation in inflow vale of wastewater also was examined on the basis of inflow data of wastewater obtained with the flow meters installed in rural sewerage facilities. Regarding to daily inflow rate of wastewater, 75 per cent probability, mid probability limits of acceptance of 0.999 under given acceptance criteria are determined from results of calculation on maximum mean and minimum daily inflow vales. The estimated values of inflow rate of wastewater are compared with design maximum and mean daily inflow rates. It is found that inflow rate of wastewater depends on number of users of rural sewerage facility, and discharge amount of drinking water. Therefore, the daily inflow rate can be predicted by considering known conditions such as number of users and discharge amount of drinking water on rural sewerage area. On the other hand. 75 per cent probability of maximum, mean, and minimum hourly inflow rates and probability limits of acceptance of 0.999 are estimated from analysis on daily variation of inflow rate of wastewater. It appears that peak coefficient may be greatly affected by the length of pipeline of rural sewerage facility. It is grasped that emergent related to maximum inflow rate of wastewater is also related to the length of pipeline of rural sewerage facility.