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Water quality and standards
Published in Sandy Cairncross, Richard Feachem, Environmental Health Engineering in the Tropics, 2018
Sandy Cairncross, Richard Feachem
From the point of view of plant growth, the major chemical criterion is the total concentration of dissolved salts, which is measured either by electrical conductivity (EC) or by total dissolved solids (TDS), and the ratio of sodium ions to calcium and magnesium ions, known as the sodium adsorption ratio (SAR). Excessive salinity prevents the proper functioning of plant cells, while excessive sodium reduces the permeability and workability of the soil. Generally, conductivities of less than 100 millisiemens/m (at 25°C) and SARs of less than 15 are acceptable. However, the effect of salinity and SAR are interdependent; the acceptability for irrigation of various waters is shown in Figure 3.3. The other important chemical parameters relate to boron (< 1.25 mg/l for sensitive crops, < 4 mg/l otherwise) and dissolved oxygen (>2 mg/l) (Pescod 1977).
Geochemical assessment of groundwater contaminants and associated health risks in the Shivalik region of Punjab, India
Published in Toxin Reviews, 2021
Sunil Mittal, Ravishankar Kumar, Prafulla Kumar Sahoo, Sunil Kumar Sahoo
Irrigation water quality indices mainly depend upon soil salinity and sodicity, which can limit plant growth in irrigated agricultural land. The accumulation of soluble salts in the soil profile is termed as soil salinity. Whenever soluble salt concentration exceeds the crop tolerance limit, it poses adverse effect on crops. Soil sodicity is another major factor affected by salinity, which infers the soil physico-chemical properties of soil (Farahmand et al. 2011). Soil sodicity becomes effective whenever the exchangeable sodium percentage (ESP) exceeds 15%. The Sodium Adsorption Ratio (SAR) estimates the degree of soil solidity (the relative amount of Na in comparison with Ca2+ and Mg2+ in transitional sites), as follows (Quirk 2001).
Human health risk and hydro-geochemical appraisal of groundwater in the southwest part of Bangladesh using GIS, water quality indices, and multivariate statistical approaches
Published in Toxin Reviews, 2023
Tapos Kumar Chakraborty, Md. Shahnul Islam, Gopal Chandra Ghosh, Prianka Ghosh, Samina Zaman, Ahsan Habib, Md. Ripon Hossain, Himel Bosu, Md. Rashidul Islam, Mostafa Al Imran, Abu Shamim Khan, Md. Shahariea Karim Josy
The concentration of EC is applied to assess irrigation suitability concerning the salinity of groundwater. Furthermore, several indices are used to determine irrigation water quality, including total hardness (TH), sodium adsorption ratio (SAR), Kelley’s ratio (KR), sodium percentage (%Na), permeability index (PI), magnesium adsorption ratio (MAR), and residual sodium bicarbonate (RSBC). All ionic concentrations are in milli equivalents per liter (meq/L) except TH (mg/L). The categories of these indices are presented in Table 4.
Multi-parametric groundwater quality and human health risk assessment vis-à-vis hydrogeochemical process in an Agri-intensive region of Indus basin, Punjab, India
Published in Toxin Reviews, 2022
Vijay Jaswal, Ravishankar Kumar, Prafulla Kumar Sahoo, Sunil Mittal, Ajay Kumar, Sunil Kumar Sahoo, Yogalakshmi Kadapakkam Nandabalan
The suitability of groundwater for irrigation was assessed using various indices (Amiri et al.2021a), such as Sodium Adsorption Ratio (SAR), Sodium Percentage (%Na), Permeability Index (PI), and Residual Sodium Carbonate (RSC) (Equations (5)–(8)).