We hypothesize that a crystallization inhibitor will induce harvestable salt efflorescence on the surface of brine-contaminated soils. If proven, the harvest of effloresced salts will provide a novel method for remediating brine spills. Our objectives were to evaluate salt efflorescence on brine-contaminated soil columns as a function of (i) crystallization-inhibitor concentration, (ii) application method, (iii) soil texture, (iv) subsequent harvesting, and (v) salt species. We conducted three laboratory incubations with 0.00001 to 0.01 M ferric hexacyanoferrate solutions applied to salt-contaminated soil columns over 7 to 28 d. The 0.01 M solution successfully effloresced an average of 0.46, 0.57, and 0.29 g g−1 (i.e., grams of harvested salt at the soil surface per total grams of NaCl applied to the soil) on sandy loam, loam, and silty clay columns, respectively. However, negligible quantities of efflorescence occurred when applying the crystallization inhibitor (i) at concentrations <0.001 M, (ii) and subsequently mixing the soil, (iii) with NaCl solutions <0.6 M, (iv) and attempting to further induce salt efflorescence after a first harvesting, and (v) to soil with elevated levels of sulfate or calcium. This novel method for brine spill remediation shows great potential for remediating NaCl-contaminated soils. Future research should include field evaluation on real brine spills to determine the efficacy of the new method in practice.

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