氯离子质量浓度与高锰酸盐指数的相关关系

The correlation between chloride ion concentration and permanganate index value

高锰酸盐指数(CODMn)是衡量水质污染的一项重要指标,其测定的准确性受多种因素的影响.对于入海河口,氯离子对CODMn测定值的干扰明显.研究表明酸性高锰酸盐指数和碱性化学需氧量均随着水中氯离子质量浓度的增加而增大,并具有良好的线性关系,但酸性高锰酸盐指数具有更明显的增大趋势,水中盐度的增加可以提高碱性化学需氧量的测定值,对钱塘江入海河口的监测结果表明,酸性高锰酸盐指数和碱性化学需氧量的差值与水样中氯离子质量浓度之间有较好的线性关系.

Permanganate index（CODMn） is an important indicator of water pollution by organic pollutants,but its determination accuracy is affected by many factors.At estuaries,the determination of CODMn value is affected by chloride ions obviously.This study indicates that both the acidic permanganate index and the alkaline chemical oxygen demand increase with the concentration of chloride ions in water,and exhibit good linear correlations.However,the acidic permanganate index has a more obvious increasing trend,and the salinity in water can increase the measuring value of alkaline chemical oxygen demand.The monitoring results from the estuary of the Qiantang River show that the difference between the acidic permanganate index and alkaline chemical oxygen is linearly correlated to the concentration of chloride ion in the water samples.