| 摘要 |
PURPOSE:To simplify measurement and to improve accuracy, by a method wherein specimen water is brought into contact with ozone under an alkaline condition to oxidize a nitrogen compound to a nitrate ion and, after the undercomposed substance is removed by adsorption, the nitrate ion is measured by an ultraviolet ray absorbing method of calculating the amount of the nitrogen compound. CONSTITUTION:Specimen water containing a nitrogen compound is collected in a reaction tank 5 through a sampling tube 1 and an alkali solution is added to the reaction tank 5 from an alkali tank 3 while ozone gas is sent into the reaction tank 5 from an ozone generator 11. Then, excessive ozone and ozone after reaction are discharged into the open air while decomposed to oxygen by an exhaust ozone decomposition device 14 and the nitrogen compound is decomposed to a nitrate ion in the reaction tank to be allowed to enter a receiver 16 from which the treated water is, in turn, sent to a filter tower 18 to remove the suspended substance therein and the org. substance in said water is adsorbed and removed by an adsorbing tower 19. Next, the specimen water is sent to an ultraviolet ray absorbing instrument 20 from the tower 19 and absorbancy is measured at a wavelength of 220nm and the concn. of the nitrate ion is calculated from a preliminarily formed calibration curve to calculate the concn. of total nitrogen. |
