CAJ | 학술논문

通过在442 nm处测定废水样品消解后剩余Cr2O2-7的吸光度,采用计算机拟合发现当化学需氧量在65～650 mg/L时,剩余Cr2O2-7的吸光度与COD浓度呈线性关系.用此法和国标法(重铬酸钾法)分别测定人工模拟废水和工业废水的COD,二者相对误差低于5.0%,表明该法具有较好的可信度和适应性,适于COD的快速准确测定.
통과재442 nm처측정폐수양품소해후잉여Cr2O2-7적흡광도,채용계산궤의합발현당화학수양량재65～650 mg/L시,잉여Cr2O2-7적흡광도여COD농도정선성관계.용차법화국표법(중락산갑법)분별측정인공모의폐수화공업폐수적COD,이자상대오차저우5.0%,표명해법구유교호적가신도화괄응성,괄우COD적쾌속준학측정.
A rapid and simple method based on visible spectrometric procedure is proposed for the determination of COD in wastewater treatment system. It is an improvement of standard method to determine COD, I.e. Determination of excess dichromate (Cr2O2-7) by visible spectrometry at 442 nm. The absorbance value (A) of Cr2O2-7 and the concentration of COD have linear relation by computer analogy, so COD is determined indirectly in this way. Some influencing factors, such as the refluxing time, the amount of wastewater sample and potassium dichromate, sulfuric acid concentration are investigated, respectively. The result shows that when the concentration of COD in wastewater sample is in the range of 65～650 mg·L-1, the results obtained by using the method presented exhibit good agreement with those given by the standard method of COD determination, and the relative error is less than 5.0%. The viability of this method is demonstrated by analyzing two kinds of synthetic wastewater and five kinds of industrial wastewater, and it proves to be a rapid and accurate method for COD determination.