Adsorption of anionic surfactants and related compounds from aqueous solution onto activated carbon and synthetic adsorbent

Abstract

SYNOPSISThe adsorption isotherms of two anionic surfactants and sodium alkyl sulfonates with various carbon numbers onto activated carbon and synthetic adsorbent were measured in aqueous solutions. The adsorption affinities remarkably increased with an increase in the length of alkyl group in the adsorbates for both adsorbents. Furthermore, the amount of adsorption increases with addition of sodium chloride into the solutions. These behaviors suggested that the effect of hydrophobic interactions seem to play an important role on adsorption of both adsorbents.

Elimination of Perfluorinated Surfactants – Adsorbent Evaluation Applying Surface Tension Measurements

“…As indicated in Fig. 6, a high ionic strength is necessary for an effective adsorption of perfluorinated surfactants, which is in agreement with the results obtained by Ihara 27. For nonfunctionalized materials this can be easily explained by the adsorption mechanism.…”

Equilibrium and kinetics study on the adsorption of perfluorooctanoic acid from aqueous solution onto powdered activated carbon

“…Because the PAC provides superior performance and operational flexibility, the use of PAC for removal of recalcitrant organics has increased in recent years [22]. Although published data on the removal of PFC surfactants are lacking, there is some evidence that non-fluorinated alkyl sulfonated compounds can be adsorbed onto activated carbon [23,24]. And researchers have discovered perfluorinated surfactants adsorbed on some natural adsorbents [25][26][27].…”

Enhanced Desorption of RDX from Granular Activated Carbon

“…The highest effluent RDX concentration (26.7 mg/L; after ''a'' in Figure 2a) was more than 10 times the RDX loading concentration and the maximum concentration that was achieved with buffered water; this was also the highest RDX concentration observed in all column experiments. Because SDS was used at a sub-CMC concentration, the most likely RDX desorption mechanism was displacement during competitive adsorption with SDS, which strongly adsorbs to GAC (Ihara, 1992). Although a detailed characterization of all mass transfer mechanisms involved was beyond the scope of this research, the observed RDX concentration increases after pumping was resumed suggest that slow intra-particle diffusion rates of SDS into the GAC (before competitive displacement of RDX) or of RDX out of the GAC (after displacement) may have limited the overall rate of RDX desorption before point ''a'' in Figure 2a.…”