In order to solve the problem that the turbidity of effluent water from high density sedimentation basin in river water pretreatment system for the Indonisian ASAM-ASAM Power Plant was too large

which caused by the upward floating of alum particle during the debugging

analysis was conducted.Poor flocculation effect due to such factors as damage of some mud valves which results in not timely mud discharge

unstable water intake into the system

improper chemical compounds adding manner

and poor stirring effect was considered as the main reason.Thus

corresponding measures were taken

such as changing the mud discharge frequency

increasing the shaft length of the agitator

controlling the flow variation of water intake

adjusting the inclination of skew plate in the sedimentation basin

and so on.After the improvement

the turbidity of the effluent water decreased to about 4 NTU

the system achieved stable operation.