【作者】 尹海龙； 郁达； 徐祖信； 李怀正；

【Author】 YIN Hai-long,YU Da,XU Zu-xin,LI Huai-zheng (Key Laboratory of Yangtze River Water Environment,Ministry of Education,Shanghai.200092;State Key Laboratory of Pollution control and Resources research.Shanghai.200092;

【机构】 长江水环境教育部重点实验室；

【摘要】 在原水输水管渠中投加粉末活性炭,对污染原水预处理,已经成为水源地突发污染事故条件下的应急处理技术手段。粉末活性炭在长距离输水管渠中可能产生沉积,影响预处理效果。针对上海市黄浦江上游水源地的原水输水渠道水流条件,基于水流剪切力相似的原则,采用环形水槽试验装置,研究了250目竹炭在水流中的沉降速率。通过建立声学多普勒测流仪反向散射强度与竹炭浓度的函数关系,实时测量竹炭浓度随水流变化,确定竹炭沉降速率。研究得出:（1）静水条件下竹炭的沉降速率为6.2×10^-4 m/s;（2）竹炭停止沉降的临界平均水流剪切力为0.31 N/m²,对应原水输水渠道中的断面水流平均速度为0.45m/s。进一步得出了原水输水渠道中竹炭沉降速率与水流的函数关系;为研究粉末活性炭在长距离输水管渠中的输移过程提供了依据。更多还原

【Abstract】 Growing interest in using powdered activated carbon（PAC） in raw water conduit,as a method of emergent treatment on the condition of sudden water pollution incident in urban drinking water supply area,raises the question of transport of PAC in the conduit,which is related to the potential PAC sedimentation along the conduit.This paper discussed the settling velocity of bamboo charcoal（250 mesh） in water flowing with the circular flume,guaranteeing the cross-sectional averaging shear stress in the actual water conduit of drinking water supply area in the upstream Hangpu River,Shanghai,China.By means of establishing the relationship between the he backscatter intensity（BSI） of an Acoustic Doppler Velocimeter（ADV） with the suspended concentration,the concentration of bamboo charcoal in water was measured in real-time,and the settling velocity of bamboo charcoal under specified shear stress was presented.The results show that:（1） The settling velocity of bamboo charcoal nearly remains unchanged within the range of less than 50 mg/L;（2） the setting velocity of bamboo charcoal in still water is 6.2×10^-4 m/s;（3） the critical shear stress for sedimentation is 0.31 N/m²,equivalent to the critical flow velocity in the actual raw water conduit. The relationship between settling velocity and averaging shear stress in water was also provided for the modeling of potential PAC sedimentation along the water conduit.更多还原