Interference of residual persulfates in wastewater to COD detection and elimination
HUANG Li-kun1, XU Yuan-yuan1, LI Zhe1, WANG Guang-zhi2, LIU Hua1, WANG Dong-dong2, FENG Li-na2
1. College of Food Engineering, Harbin University of Commerce, Harbin 150076, China; 2. State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
Abstract: To study the influence of residual persulfates during the treatment of organic wastewater by activated persulfate oxidation on the determination of COD in water samples, the influence of persulfate ion on the determination of COD is investigated, the interference mechanism is analyzed and the optimized method to eliminate interference is proposed. Research results show that 352 nm and 420 nm wavelengths can serve as the determination of persulfate anions to ignore the spectral interference from the reagent matrix. If the solution contains a high concentration of persulfate ion (0-25 g·L-1) after water sample has been treated by persulfate activation, the absorbance value of diluted water sample at 352 nm is determined, the linear relation equation is y=0.021 4x-0.001 3, R2=0.999 2. If the solution contains a low concentration of persulfate ion (0-2.5 g·L-1), the absorbance shall be determined at 420 nm for un-diluted water sample, and the linear relation equation is y=0.255 6x-0.006, R2=0.999 3. A linear equation between the concentration of persulfates and COD value consumed is y=18.838 94x-7.115 49, R2= 0.999 26.
黄丽坤, 徐媛媛, 李哲, 王广智, 刘华, 王东东, 冯丽娜. 废水中残留过硫酸盐对COD检测的干扰及消除方法[J]. 现代化工, 2021, 41(8): 248-252.
HUANG Li-kun, XU Yuan-yuan, LI Zhe, WANG Guang-zhi, LIU Hua, WANG Dong-dong, FENG Li-na. Interference of residual persulfates in wastewater to COD detection and elimination. Modern Chemical Industry, 2021, 41(8): 248-252.