Patent ID: 7820038
Filing Date: 2010-10-26
Classification: B01D,C02F

Abstract:
1. A water treatment system for performing a water purifying treatment by use of ultraviolet radiation, comprising: a coagulation/sedimentation basin-containing system comprising means to perform a coagulation/sedimentation treatment process mixing water being treated with an aggregating agent; a first ultraviolet radiation device which radiates ultraviolet to a raw water in a front stage process of the coagulation/sedimentation treatment process, the first ultraviolet radiation device located to treat the raw water before entering the coagulation/sedimentation basin; a second ultraviolet radiation device comprising ultraviolet lamps located to radiate ultraviolet to the water treated in the front stage process in a rear stage process of the coagulation/sedimentation treatment process, the second ultraviolet radiation device located to treat the water downstream from the coagulation/sedimentation basin; a raw water ultraviolet transmissometer which is located to measure an ultraviolet transmittance of the raw water at the front stage process; a sedimented water ultraviolet transmissometer which is located to measure an ultraviolet transmittance of sedimented water at the rear stage process; and a control system comprising a control unit which controls the first and second ultraviolet radiation devices, wherein the control system is operable such that the control unit is responsive to a measurement result of the raw water ultraviolet transmissometer showing a higher transmittance than a preset reference value, so that the control unit makes a control to decrease an output of the ultraviolet lamps built in the second ultraviolet radiation device to a lower limit value, and the control unit is responsive to a measurement result of the raw water ultraviolet transmissometer showing a lower transmittance than the preset reference value, so that the control unit makes a control to stop the operation of the first ultraviolet radiation device, and to make the output of the ultraviolet lamps built in the second ultraviolet radiation device higher than a standard value.