Study on transport of powdered activated carbon using a rotating circular flume

This study employed a rotating flume to examine the Powdered Activated Carbon(PAC)transport with water flow.The initial PAC concentration was 10 mg/L-30 mg/L,and PAC concentration versus time under a specified cross-sectional averaging fluid shear was observed.Results show that compared with PAC deposition in still water,PAC is depleted to zero faster under a fluid shear of 0.02 Pa,due to PAC agglomeration with the fluid shear.However,since PAC floc size only ranges from a single particle(2 m)to approximate 6 m,an increasing of instantaneous turbulent fluctuations could counteract the force of PAC floc settling downward,and as a result the steady PAC concentration increases with the increase of shear stress.It is found that the critical shear stress for PAC deposition is about 0.60 Pa,and further the PAC deposition probability is presented according to the experimental scenarios between 0.02 Pa and 0.60 Pa.Combining the PAC transport and deposition formula with PAC-pollutant removal model provides an insight into PAC deployment in raw water aqueduct for sudden open water source pollution.