CAJ | 학술논문

综述密封高温快速测定COD在610 nm、420 nm和348 nm三种波长条件下的特点。前二者已定为国家标准方法，研究发现348nm灵敏度最高，可以测定超低量程的COD，其准确度4.5%、精密度5.2%，检出限1.6 mg/L，建议也将其定为国家标准方法。COD测定都加Hg2+掩蔽Cl-，无汞法不加Hg2+，只加Ag+或加Ag+又加Cr3+；前者COD测定值偏高，后者的Cr3+使Cr（V1）/Cr3+电极电势下降，虽然有抑制Cl-的氧化作用，但灵敏度下降，有机物氧化率下降，测定结果偏低较大。如果要求测定准确度高，无汞不行。测定废液中加入铁或铜，回收汞银。
종술밀봉고온쾌속측정COD재610 nm、420 nm화348 nm삼충파장조건하적특점。전이자이정위국가표준방법，연구발현348nm령민도최고，가이측정초저량정적COD，기준학도4.5%、정밀도5.2%，검출한1.6 mg/L，건의야장기정위국가표준방법。COD측정도가Hg2+엄폐Cl-，무홍법불가Hg2+，지가Ag+혹가Ag+우가Cr3+；전자COD측정치편고，후자적Cr3+사Cr（V1）/Cr3+전겁전세하강，수연유억제Cl-적양화작용，단령민도하강，유궤물양화솔하강，측정결과편저교대。여과요구측정준학도고，무홍불행。측정폐액중가입철혹동，회수홍은。
An overview on the characteristics of COD rapidly determined in the condition of seal and high temperature under 3 different wavelengths of 610 nm,420 nm and 348 nm. The determination methods under the first two wavelengths have been accepted as the national standard measurements,while from the research,we find that under the wavelength of 348nm,the sensitivity of COD is highest so ultra-low-range COD can be determined and we suggest to list COD determina-tion under 348nm wavelength as another national standard measurement. The accuracy、precision and detection limit of this methods are ,4.5%、5.2%and 1.6 mg/L,respectively.COD measurement is required to add Hg2+and mask Cl-and mercury-free method is free of Hg2+and only adding Ag+or Ag+and Cr3+. Only adding Ag+,COD determine value will be higher than the actual value and if adding Ag+and Cr3+,Cr3+will decline electrode potential of Cr(Vl)/Cr3+which though is able to re-strain the oxidation of Cl-,the sensitivity of COD decreases and oxidation rate of organic matter decreases leading a lower COD determine value. Mercury cannot be free if an accurate determine result is required. Add copper or iron in the waste liquid could recovery mercury-silver.