TY - JOUR
T1 - Unprecedented biodesalination rates–Shortcomings of electrical conductivity measurements in determining salt removal by algae and cyanobacteria
AU - Zafar, Abdul Mannan
AU - Javed, Muhammad Asad
AU - Aly Hassan, Ashraf
N1 - Funding Information:
This work was supported by the National Water Center and United Arab Emirates University [grant number G00003297 and G00003501 ]. We want to thank United Arab Emirate University (UAEU) for funding acquisition and conducting the laboratory experiments. We also pay our gratitude to anonymous reviewers for reviewing this manuscript.
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2022/1/15
Y1 - 2022/1/15
N2 - Phormidium keutzingianum performed biodesalination of brackish water (10 g/L). The electrical conductivity (EC) was measured to evaluate the salt concentration over 80 days of cyanobacterial inoculation. Anion concentrations were measured using ion chromatography to estimate salt removal. EC-based measurements showed ∼8–10% removal efficiency in the first 20 days. However, the removal efficiency based on chloride ion concentration showed ∼40% removal in the same time frame. The pH increase was observed with growth of algal biomass. The increasing pH proposes the formation of hydroxyl and carbonate ions. Sulfuric acid was added at day 110 to neutralize them. At pH 4, the EC reduced significantly to about ∼37% confirming the chloride removal. EC should not be used to measure salt reduction as it is an obscure parameter, and therefore, EC is not the best choice to measure salinity removal using algae. Some recently published studies used only EC to estimate biodesalination, and it is anticipated that salt removal is misrepresented in those studies.
AB - Phormidium keutzingianum performed biodesalination of brackish water (10 g/L). The electrical conductivity (EC) was measured to evaluate the salt concentration over 80 days of cyanobacterial inoculation. Anion concentrations were measured using ion chromatography to estimate salt removal. EC-based measurements showed ∼8–10% removal efficiency in the first 20 days. However, the removal efficiency based on chloride ion concentration showed ∼40% removal in the same time frame. The pH increase was observed with growth of algal biomass. The increasing pH proposes the formation of hydroxyl and carbonate ions. Sulfuric acid was added at day 110 to neutralize them. At pH 4, the EC reduced significantly to about ∼37% confirming the chloride removal. EC should not be used to measure salt reduction as it is an obscure parameter, and therefore, EC is not the best choice to measure salinity removal using algae. Some recently published studies used only EC to estimate biodesalination, and it is anticipated that salt removal is misrepresented in those studies.
KW - Biodesalination
KW - Brackish water
KW - Electrical conductivity
KW - Halotolerant algae
KW - Phormidium keutzingianum
KW - Salinity
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U2 - 10.1016/j.jenvman.2021.113947
DO - 10.1016/j.jenvman.2021.113947
M3 - Article
C2 - 34678537
AN - SCOPUS:85117332953
VL - 302
JO - Journal of Environmental Management
JF - Journal of Environmental Management
SN - 0301-4797
M1 - 113947
ER -