盐度对以葡萄糖为底物的化学需氧量测定的影响及校正  

Influence of Salinity on Chemical Oxygen Demand(COD)Measurement and Its Correction with Glucose as the Substrate

作　　者：李耀如[1] 张龙军[1,2] 

机构地区：[1]中国海洋大学环境科学与工程学院,山东青岛266100 [2]中国海洋大学海洋环境与生态教育部重点实验室,山东青岛266100

出　　处：《中国海洋大学学报（自然科学版）》2016年第1期93-100,共8页Periodical of Ocean University of China

基　　金：国家自然科学基金委员会--山东省人民政府联合资助海洋科学研究中心项目(V1406403);国家自然科学基金项目(41376123);国家自然科学基金创新研究群体项目(41221004)资助~~

摘　　要：海水化学需氧量(COD)是海水水质的重要检测指标,然而在河口及近岸海域的低盐环境下,由于受到Cl^-的干扰,其实测值无法准确反映近岸盐度较低海域的有机污染程度。本文研究了不同盐度条件下,Cl^-对以葡萄糖为底物的COD测定的影响过程,对比分析了Cl^-对COD和淡水碱性高锰酸盐指数(COD_(Mn))测定的影响程度,以期获得这两种方法测定结果可对应的依据。结果表明:海水COD测定方法在S≈25~35区间内是稳定的,但在S≈0~25区间,测定方法的氧化率随Cl^-浓度的降低而下降,而且有机物浓度越低氧化效率越低。Cl^-对海水COD测定的影响发生在碱性KMnO_4加热氧化有机物阶段。淡水碱性COD_(Mn)测定方法在S≈0~10区间内的氧化效率与海水COD方法在S≈25~35区间内的氧化率相当,并初步提出了以葡萄糖为底物的低盐区COD测定值的校正式,这对于准确认识盐度较低的河口及近岸海域有机污染程度是非常有益的。Chemical oxygen demand（COD）is one of the routine monitoring indicators of marine water quality.However,due to influence of Cl--in low-salinity areas of estuaries and offshore waters,COD measured values cannot exactly reflect organic pollution level in these areas.This paper researched the influence of Cl--on the COD measurement at diverse salinities with glucose as the substrate,and also compared it with the effect of Cl-- on the measurement of alkaline permanganate index（COD_（Mn））in order to acquire evidence of the correspondence between COD and COD_（Mn）.The results indicated that COD measuring method was stable within the salinity range from 25 to 35,while its oxidation efficiency declined as Clconcentration decreased within the salinity range from 0 to 25 and the decline was more obvious even when organics concentration was low.Cl--influenced the process of alkaline potassium permanganate oxidizing reducing substances during COD measurement.The oxidation efficiency of alkaline COD_（Mn） measuring method within the salinity range from 0 to 10 was almost equivalent to that of COD from 25 to 35,therefore a correcting formula for COD measured values aiming at the influence of Cl--was obtained with glucose as the substrate.The raise of the correcting formula was favorable to understanding organics pollution accurately in low-salinity estuaries and offshore waters.

关 键 词：海水化学需氧量(COD) 氯离子干扰 校正方法 

分 类 号：P229.2[天文地球—大地测量学与测量工程]