浄水場原水のpH変動と浄水中の残留アルミニウムへの影響

摘要

S市のF浄水場は，Nダムの放流水とMダム貯留水を混合して原水としている。取水比率はNダムの放流水は約8割，Mダム貯留水は約2割である。Nダムの放流水は，河川を約15km流下した後に取水されているので，河川水と貯水池の双方の水質的特徴を併せ持っていると考えることができる。%The relation between the changing of pH of raw water and turbidity.the removal rate of sedimentation and the influence to residual aluminium in treated water by pH changing of raw water are studied by the references for water treatment plant and experiment for coagulation-sedimentation.rnCleared points are as follows ;rn1) The pH of raw water is changed by photosynthesis in case average turbidity of raw water is less than 20 degree/h,rn2) The range of changing pH is around 0.2 to 0.8 in F water treatment plant,rn3) The removal rate of sedimentation goes down in case turbidity <5 degree and pH>7 of raw water,rn4) In case of changing pH to alkali side.the coagulant dosage have to be adjusted correspond to the change of pH for protection of decreasing the removal rate and going up the residual aluminum.