Effect of Crystallization Inhibitors on the Upward Migration and Harvesting of Salts on Oil-Production-Water Contaminated Soils.

Oil-production-water (NaCl-based brine) contamination of soils is an issue of great concern in areas of oil and gas exploration. Many remediation methods have been used with little success in an effort to reduce salt contamination and allow vegetation regrowth. However, the use of crystallization inhibitors for extracting salts and suppressing salt damage to building materials has previously been reported in the literature. We hypothesize that these crystallization inhibitors can be used to successfully harvest salts from oil-production-water contaminated soils. The objectives of this study were to 1) determine if the application of crystallization inhibitors to soil can extract salts and be used as an in situ remediation method on salt-contaminated soils and 2) determine if the migration and extraction of salts are a function of crystallization inhibitor concentration, application method, and soil type. In a laboratory study, four concentrations (0.01 to 0.00001M) of a crystallization inhibitor was applied to NaCl contaminated soils (sandy loam, loam, and clay) using three methods of application and allowed to incubate for 7 days after observing efflorescence.  Between 43 and 62% of the applied salts effloresced and were accessible for harvesting when a 0.01M concentration of the crystallization inhibitor was surface applied to sandy loam and loam soils. Negligible quantities of salts were able to be harvested when the crystallization inhibitor was incorporated into the soil or when the two lowest concentrations were applied regardless of application method. Based on these results, the use of crystallization inhibitors appears to be feasible for remediating salt-contaminated soils.