Incorporating solution alkalinity into a hydraulic reduction model to account for disaggregation and dispersion

Ali, Aram ORCID: https://orcid.org/0000-0003-2986-9220 and Bennett, John McL. and Biggs, Andrew J. W. and Marchuk, Alla (2022) Incorporating solution alkalinity into a hydraulic reduction model to account for disaggregation and dispersion. Geoderma, 413:115742. pp. 1-11. ISSN 0016-7061


Abstract

The use of alkaline and sodic water for irrigation has increased in recent years due to constrained freshwater sources and a rapid increase in industrial by-product wastewater from industries such as coal seam gas and effluent management from other industrial sources. The use of alkaline sodic water can significantly impact soil condition, in particular soil physical properties. The threshold electrolyte concentration (CTH) is generally used to assess soil structural stability when it is subjected to a solution of a given sodium adsorption ratio and electrolyte concentration. The current disaggregation model commonly used is mainly based on the sodium and calcium system, without considering the adverse effects of alkaline anions (e.g., HCO3–) reducing saturated hydraulic conductivity (Ks). This study aimed to assess the incorporation of HCO3– into the semi-empirical disaggregation model approach to determine CTH. The percentage reduction in Ks increased with increasing solution alkalinity and this reduction rate was dependent on soil type. The results indicated that there is a correlation between the reduction of Ks produced by non-alkaline and alkaline solutions represented as SAR and adjusted SAR (SARadj) for up to 30% Ks reduction. This association confirms that the effect of SAR and SARadj on CTH are similar. Therefore, HCO3– can be incorporated into the current disaggregation model to determine CTH (≤20% Ks reduction) for alkaline irrigation waters when disposed of on lands.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Faculty/School / Institute/Centre: Current - Institute for Life Sciences and the Environment - Centre for Sustainable Agricultural Systems (1 Aug 2018 -)
Faculty/School / Institute/Centre: Current - Institute for Life Sciences and the Environment - Centre for Sustainable Agricultural Systems (1 Aug 2018 -)
Date Deposited: 21 Mar 2022 01:21
Last Modified: 21 Mar 2022 01:21
Uncontrolled Keywords: Alkaline water; Hydraulic conductivity; Salinity; Sodicity; Threshold electrolyte concentration; Wastewater
Fields of Research (2008): 05 Environmental Sciences > 0503 Soil Sciences > 050304 Soil Chemistry (excl. Carbon Sequestration Science)
05 Environmental Sciences > 0503 Soil Sciences > 050305 Soil Physics
05 Environmental Sciences > 0503 Soil Sciences > 050399 Soil Sciences not elsewhere classified
Fields of Research (2020): 41 ENVIRONMENTAL SCIENCES > 4106 Soil sciences > 410605 Soil physics
41 ENVIRONMENTAL SCIENCES > 4106 Soil sciences > 410699 Soil sciences not elsewhere classified
Socio-Economic Objectives (2008): D Environment > 96 Environment > 9614 Soils > 961499 Soils not elsewhere classified
Socio-Economic Objectives (2020): 18 ENVIRONMENTAL MANAGEMENT > 1806 Terrestrial systems and management > 180605 Soils
Identification Number or DOI: https://doi.org/10.1016/j.geoderma.2022.115742
URI: http://eprints.usq.edu.au/id/eprint/47034

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