ULTRAVIOLET IRRADIATION METHOD IN DEACTIVATION TREATMENT OF PROTOZOANS

• Main Authors: NAGAI TORU, YAMASHITA OSAMU, FUJITA KUNIO
• Format: Patent
• Language: English
• Published: 09.09.2004
• Edition: 7
• Subjects: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; CHEMISTRY; METALLURGY; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; THEIR RELEVANT APPARATUS; TRANSPORTING; TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE

PROBLEM TO BE SOLVED: To provide an ultraviolet irradiation method for controlling the necessary ultraviolet irradiation quantity of an ultraviolet sterilizing lamp in order to deactivate protozoans such as cryptosporidium or the like. SOLUTION: In the ultraviolet irradiation method in the deactivation treatment of protozoans, the turbidity state of water (b) to be treated is measured, and the measured value of this turbidity (d) and the necessary ultraviolet irradiation quantity preset to the turbidity corresponding to fluctuations in a turbidity state of 0-20° are comparatively operated to calculate the current value of the ultraviolet irradiation quantity to the turbidity (d). The current quantity (f) of a current allowed to flow to the ultraviolet sterilizing lamp (4) is controlled to irradiate the water to be treated so that the necessary ultraviolet irradiation quantity becomes 0-10 mWsec/cm2. By this method, protozoans such as cryptosporidium or the like can be deactivated and the use of the waste energy of the ultraviolet sterilizing lamp for irradiating the water to be treated is eliminated. COPYRIGHT: (C)2004,JPO&NCIPI