Recovery of aromatic sulfonic acids and quaternary ammonium compounds from aqueous streams by adsorption

Organic Pollutants in Shale Gas Flowback and Produced Waters: Identification, Potential Ecological Impact, and Implications for Treatment Strategies

“…Efficient removal of PAHs, including naphthalene and phenanthrene, quaternary ammonium compounds, 2-butoxyethanol, and chlorinated organic compounds via sorption to activated carbon was reported in the literature − However, removal of phthalates by activated carbon is inefficient, especially at basic pH, because of the increased electrostatic resistance between negatively charged activated carbon surface and phthalate anions, produced under basic conditions. , Low affinity of phthalates to activated carbon will ultimately result in low performance of full scale installation, as shown by Asakura and Matsuto (2009), who predicted 50–70% removal of DEHP from leachate, based on carbon utilization rate of 1 kg/m 3 ·d and initial DEHP concentration of 50 μg/L …”

“… 89 , 95 Thus, adsorption of benzyltriethylammonium chloride in the presence of NaCl (Freundlich adsorption constant K f = 285 mg/g) is higher than its adsorption in fresh water solution ( K f = 235 mg/g). 90 Increased adsorption of PAH to different adsorbents with increased salt concentration was reported by several authors. 95 At the same time, high salinity does not influence or may even enhance the adsorption of strongly hydrophobic compounds with low solubility, such as naphthalene or di- n -butyl phthalate, at low concentrations.…”

“…High water salinity has several opposite effects on the adsorption of organic compounds. It is widely accepted that increased salinity improves sorption of organic compounds to activated carbon decreasing their solubility in the solution (so-called “salting out effect”) and suppressing electrostatic repulsions between organic compounds and activated carbon. , Thus, adsorption of benzyltriethylammonium chloride in the presence of NaCl (Freundlich adsorption constant K f = 285 mg/g) is higher than its adsorption in fresh water solution ( K f = 235 mg/g) . Increased adsorption of PAH to different adsorbents with increased salt concentration was reported by several authors .…”