This invention provides a
water quality monitoring method for
treated water that confirms that the
treated water, after coagulation and
sedimentation treatment of COD /
phosphorus /
nitrogen /
cyanide in collected dust (
raw water), meets
water quality standards, predicts deterioration in treatment efficiency during coagulation and
sedimentation treatment, enables
early detection of abnormal water, and facilitates
rapid response to abnormal water. [Solution] A
water quality monitoring method for
treated water, comprising: a measurement step for automatically measuring the amount of COD /
phosphorus /
nitrogen /
cyanide in treated water; a coagulation-
sedimentation step for obtaining treated water by circulating
raw water containing coagulated material including
copper, iron, etc., and performing mixing, coagulation, and sedimentation treatment in that order; a sampling and analysis step for collecting an analytical sample, in which a portion of the
raw water in a
mixing tank is intermittently separated while it is circulating, a portion of the separated raw water is injected under pressure into the cylinder of a cylindrical
ceramic filter which is a porous material, a portion of the filtered water obtained is taken out, and the filtered water is automatically introduced into an analytical device as an analytical sample for measuring the amount of
nitrogen, etc. in the raw water, and the amount of nitrogen, etc. in the sample is automatically measured; and a control step for controlling the operating conditions of the coagulation-sedimentation step using the measured values obtained in the analysis step.