浅谈测定五日生化需氧量的控制手段

Control Method for Measuring Five-day Biochemical Oxygen Demand

从接种稀释水、水样稀释倍数、仪器准确度三个方面分析五日生化需氧量(BOD_(5))测定过程的注意事项。接种稀释水数值的大小可通过接种液的用量来调节,并用标准样品作为质控手段检查接种液。然后通过水样的特征或者结合化学需氧量的数值对BOD_(5)结果进行预判并确定合适的稀释倍数。最后用碘量法与电极法做比对,在确定仪器性能正常的情况下进行测定,得到准确的数值。

The precautions of the five-day biochemical oxygen demand(BOD_(5))determination process were analyzed from the three aspects of inoculation dilution water,water sample dilution multiple and instrument accuracy.The value of the inoculation dilution water can be adjusted by the amount of the inoculum,and the standard sample was used as a quality control method to check the inoculum.Then the characteristics of the water sample or combined with the value of the chemical oxygen demand were used to predict BOD_(5) results and determine the appropriate dilution factor.Finally,comparing the iodometric method with the electrode method,and the sample was measured after confirming that the instrument performance was normal.The accurate values were obtained.