地表水水质硬度测定中的空白值影响及修正模型研究

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关键词：水质硬度；空白值；修正模型；乙二胺四乙酸二钠（EDTA-2Na）；稀释倍数 中图分类号：X832 文献标识码：A 文章编号：1008-9500（2025）05-0038-03 DOI： 10.3969/j.issn.1008-9500.2025.05.008

Abstract： Water hardnessis one of the basic items in water environment monitoring，which can characterize the concentrationof multivalent metal ions suchascalciumand magnesium in water，and isan importantbasis forjudging the safetyof drinking water and the applicabilityof industrial water.Theexperiment focuses on the interference problemof blank values in waterqualityhardnessdetermination，and proposes and validatesanaccurate methodfor measuringthe total hardness of water quality basedon a blank valuecorrection model.The experiment uses ethylenediaminetetraacetic acid disodium salt （EDTA-2Na）standard solution，combined with standard water samplesand actual surface water samples，to analyzethe significant influence of blank values on the measurement results under high dilution conditions.The research results ndicate that the uncorrected hardness measurement values are higher，with a relative error of up to 1.75% ; after introducing the correction model， the error is significantly reduced to 0.40% . The correction model is not only applicable forhardess testingofsurface water，roundwater，andindustrial wastewater，butalsoprovidesimportantreferencesforthe accurate determination ofother water quality indicators，and provides theoretical supportfor high-precision waterquality monitoring and management.

KeyWords：waterqualityhardnes;blank value;corrction model; ethylenediaminetetraceticacid disodiumsalt（EDTA2Na）; dilution ratio

作为水环境监测的基本项目之一，水质硬度是水中钙、镁等多价金属离子浓度的重要评价指标，可以确保饮用水安全性和工业用水适用性。（剩余3670字）