Physiological Response of and to Salinity and Hydraulic Fracturing Wastewater: Potential for Phytoremediation Applications.

Natural and anthropogenic soil degradation is resulting in a substantial rise in the extension of saline and industrially-polluted soils. Phytoremediation offers an environmentally and economically advantageous solution to soil contamination. Three growth trials were conducted to assess the stress tolerance of native Canadian genotypes of L., Michx., and one hybrid willow ( × ) to salinity and hydraulic fracturing (fracking) wastewater. Thirty-three genotypes were grown in NaCl or fracking wastewater solutions between 0 and 7 mS over a period of 3-4 months. was observed to be relatively salt-intolerant compared to and hybrid willow, which is likely caused by an inability of to restrict Na translocation. Photosynthesis and transpiration decreased with salinity treatments, and severe reductions occurred with exposure to fracking solutions. Raffinose and stachyose content was tripled in leaf and root tissues. In willows, Na was primarily confined to root tissues, Cl accumulated up to 5% dry weight in leaves, and K was translocated from roots to leaves. Willow genotypes CAM-2 and STL-2 displayed the greatest maintenance of growth and resistance to necrotic symptoms in all trials, suggesting that these genotypes may be useful for practical application and further field study.