Characterization of saline groundwater resource quality for aquatic biomass production: A statistically-based approach

A study was conducted to determine if the saline groundwaters of New Mexico could be statistically reduced to a few major types based on ionic composition. A decreased number of water types could then be used to screen candidate microalgal strains for tolerance to various environmental conditions and for biomass production potential. Two major water types were identified, both with average salinities of 4000 mg l^-1 TDS. Type I water had a much higher divalent ion concentration than Type II water and was dominated by Na⁺, C1^-, Mg²⁺, and Ca²⁺. The major ions in Type II water were Na⁺, Cl^-, SO₄^2-, and HCO₃^-. The relative ionic composition of the two water types that were derived from the analysis of saline groundwater were also representative of the ionic composition of the saline surface waters of the southwestern United States. The growth rates of several microalgal strians were measured in the two water types over a range of temperatures (10-35°C) and conductivities (10-70 mmho cm^-1). The algae exhibited a wide range of growth responses to the water types indicating the importance of screening the strains with waters which would be available for biomass production.