工业废水中溴离子对COD测定的影响

Effect of Bromide Ion in Industrial Wastewater on Chemical Oxygen Demand Determination

研究了工业废水中高浓度溴离子对COD测定的干扰,考察了有机物浓度、溴离子浓度与表观COD值之间的关系,并初步探索了隐蔽溴离子的方法。结果表明,当溴离子浓度一定时,有机物浓度越低,溴离子对表观COD值的贡献越大;当有机物浓度一定时,溴离子浓度越小,单位质量溴离子对COD的贡献越大;含溴废水中有机物的实际COD可通过表观COD与Br-对COD的贡献值之差进行估算。试验还发现,硫酸汞不能消除溴离子对COD测定的干扰;硝酸铬和硫酸铝也不能有效地隐蔽溴离子。

The effect of high-concentration bromide ion in industrial wastewater on COD determination was studied. The relationship of organic and bromide ion concentration with apparent COD value was investigated. The method to mask bromide ion was discussed preliminary. The results show that the bromide ion contribution to apparent COD value increases as the organic concentration decreases at a given bromide ion concentration, and the unit mass of bromide ion contribution to apparent COD value in creases as the bromide ion concentration decreases at a given organic concentration. The actual COD concentration of organic matter in a wastewater containing bromide can be estimated by the difference be- tween apparent COD and bromide contribution to COD. The effect of bromide ion on COD determination can not be eliminated by mercuric sulfate. Also, both chromic nitrate and aluminium sulfate can not mask effectively the bromide ion.