In order to systematically explore the influence of chloride ions on COD,and ob-tain an effective masking method to reduce detection error.This paper takes COD standard solution as the research object,discusses the influence of chloride ion and mercury sulfate on COD test value.The experimental results show that chloride ion has significant interfer-ence on COD test,especially for samples with small COD value,resulting in greater test error.Mercury sulfate has a good masking effect,when the masking ratio is 30:1,the test error can reach less than 10.00％for samples with COD≥200 mg/L.For samples with COD≤50 mg/L,the low concentration test condition can achieve a better masking effect when the masking ra-tio is 20:1,but the amount of mercury sulfate should not be too much and should be added after measuring the sample.
维普
万方数据