Comparison of electrical conductivity calculation methods for natural waters

Abstract

The capability of eleven methods to calculate the electrical conductivity of a wide range of natural waters from their chemical composition was investigated. A brief summary of each method is presented including equations to calculate the conductivities of individual ions, the ions incorporated, and the method's limitations. The ability of each method to reliably predict the conductivity depends on the ions included, effective accounting of ion pairing, and the accuracy of the equation used to estimate the ionic conductivities. The performances of the methods were evaluated by calculating the conductivity of 33 environmentally important electrolyte solutions, 41 U.S. Geological Survey standard reference water samples, and 1593 natural water samples. The natural waters tested include acid mine waters, geothermal waters, seawater, dilute mountain waters, and river water impacted by municipal waste water. The three most recent conductivity methods predict the conductivity of natural waters better than other methods. Two of the recent methods can be used to reliably calculate the conductivity for samples with pH values greater than about 3 and temperatures between 0 and 40°C. One method is applicable to a variety of natural water types with a range of pH from 1 to 10, temperature from 0 to 95°C, and ionic strength up to 1 m.

Impact of Sodium Humate Coating on Collector Surfaces on Deposition of Polymer-Coated Nanoiron Particles

“…The Na humate solutions were characterized in terms of: (1) electrical conductivity (EC) and pH (both measured using standard electrodes, WTW GmbH, Germany), and IS (calculated from the EC after McCleskey et al 17 ); (2) dissolved organic carbon (DOC) content (measured with a TOC-L CPH TOC analyzer; Shimadzu, Japan); and (3) MW distributions determined by size-exclusion chromatography (SEC). In order to avoid clogging of the size-exclusion column by high MW moieties, Na humate solutions were first filtered through a 0.1 µm polyvinylidene fluoride membrane.…”

Presence and Consequences of Coexisting Methane Gas With Hydrate Under Two Phase Water‐Hydrate Stability Conditions

“…The resistivity of brine is temperature‐dependent, and we calibrated it using the following expression (e.g., McCleskey et al, ): where T (°C) is temperature, α is the temperature compensation factor, and ρ 25 (Ωm) is the resistivity of brine at 25°C. Values of ρ 25 were measured using a conductivity meter with α = 1.9%, similar to other studies (e.g., McCleskey et al, ).…”

“…The resistivity of brine is temperature‐dependent, and we calibrated it using the following expression (e.g., McCleskey et al, ): where T (°C) is temperature, α is the temperature compensation factor, and ρ 25 (Ωm) is the resistivity of brine at 25°C. Values of ρ 25 were measured using a conductivity meter with α = 1.9%, similar to other studies (e.g., McCleskey et al, ). For a mixture of sand and clay, the CEC can be calculated from where m c is the mass fraction of clay minerals in the whole rock, χ i is the relative volume fraction of each clay mineral, and CEC i is the cation exchange capacity of each clay mineral.…”

Study on the relationship between total dissolved solids (TDS) and electrical conductivity (EC) of the aquifers in Ca Mau province

“…Hàm lượng TDS được coi là chỉ số về độ mặn của nước và thường được xác định trong phòng thí nghiệm [1][2][3][4][5][6][7][8]. Khi muối được hòa tan trong nước, các ion của chúng sẽ tách ra và làm tăng lượng chất rắn hòa tan trong dung dịch và cả độ dẫn điện EC [9].…”