低温冷却对COD测定结果的影响

Effect Of Low Temperature Cooling on COD Measurement Results By

化学需氧量(COD)能精确地表示污水中有机物含量,它是衡量污水处理厂进、出水水质情况的重要指标,根据城镇污水处理厂运行、维护及安全技术规程(CJJ60-2011)中规定COD的检测周期为每日一次。COD的检测方法之一为重铬酸钾法(GB11914-89),由于此方法检测范围广、准确度高,被广泛应用于水样COD的日常检测。此方法在检测过程中,经加热消解回流后,需冷却到室温,不能有温感后才能进行滴定,否则会引起结果偏低,自然冷却需时较长。

Chemical oxygen demand(COD)can accurately represent the organic matter content in sewage.It is an important indicator to measure the water quality of sewage treatment plants.According to the operation,maintenance and safety technical regulations of urban sewage treatment plants(CJJ60-2011)The detection period for COD is specified once a day.One of the methods for detecting COD is potassium dichromate method(GB11914-89).Because of its wide detection range and high accuracy,it is widely used in the daily detection of COD in water samples.In the detection process,after heating and digesting,it needs to be cooled to room temperature,and the titration cannot be performed after the temperature is not felt,otherwise the result will be low,and the natural cooling takes a long time.