五日生化需氧量测定中过饱和溶解氧快速逸出方式探讨  

作　　者：胡芹芹 罗德伟 魏国芬 徐雯 陈倩 

机构地区：[1]湖北省生态环境厅襄阳生态环境监测中心,湖北襄阳441000

出　　处：《环境保护与循环经济》2024年第10期84-88,110,共6页environmental protection and circular economy

摘　　要：冬季自然水体中溶解氧通常为过饱和状态,测定五日生化需氧量(BOD_(5))要求培养前振荡赶出过饱和溶解氧,采用人工振荡、超声波振荡、静置抽真空和抽真空振荡4种不同前处理方式对样品中过饱和溶解氧的逸出进行对比研究。结果表明:抽真空振荡方式能使样品中过饱和溶解氧快速逸出,且逸出速率与样品初始溶解氧浓度、取样体积成正比。当样品体积为600 mL、溶解氧浓度为9~10 mg/L时,抽真空振荡10 s可逸出过饱和溶解氧;溶解氧浓度为10~12 mg/L时,20~30 s可逸出过饱和溶解氧;溶解氧浓度大于12 mg/L时,50~70 s可逸出过饱和溶解氧。抽真空振荡方式能在10~70 s快速逸出样品中过饱和溶解氧,BOD_(5)测定结果准确,相对偏差小,缩减和降低了样品测定过程中过饱和溶解氧逸出的时间和难度,为实验室BOD_(5)的测定分析提供了参考和依据。The dissolved oxygen in natural water in winter is usually super-saturated.The five-day biochemical oxygen demand(BODs)was determined by shaking out supersaturated dissolved oxygen before culture,the escape of super-saturated dissolved oxygen in samples was studied by artificial oscillation,ultrasonic oscillation,static vacuuming and vacuum oscillation.The results show that the vacuum oscillation mode can make the super-saturated dissolved oxygen in the sample escape quickly,and the escape rate is proportional to the initial dissolved oxygen concentration and the sample volume.When the sample volume is 600 mL and the concentration of dissolved oxygen is 9-10 mg/L,the super-saturated dissolved oxygen can be escaped by vacuum oscillation for 10 s;when the concentration of dissolved oxygen is 10-12 mg/L,the super-saturated dissolved oxygen can be escaped by vacuum oscillation for 20-30 s;when the concentration of dissolved oxygen is>12 mg/L,the super-saturated dissolved oxygen can be escaped by vacuum oscillation for 50-70 s.The vacuum oscillation mode can quickly escape the super-saturated dissolved oxygen in the sample in 10-70 s,and the results of BOD_(5) determination were accurate and the relative deviation was small.The time and difficulty of escape of supersaturated dissolved oxygen were reduced by vacuum oscillation method,which provided reference and basis for BOD,determination in laboratory.

关 键 词：BOD_(5) 过饱和溶解氧 逸出 抽真空振荡 

分 类 号：X824[环境科学与工程—环境工程]