(373d) Ash Modified with Surface Active Agents for the Adsorption of Chloro/Nitro Benzenes from Aqueous Phase

Boiler fly ash, collected from ICI soda ash plant, Pakistan, was modified by two different ionic surfactants namely hexadecyltrimethyl ammonium bromide (HDTMA) and sodium dodecyl sulfate (SDS), separately. Surfactant treated ash was characterized by SEM, TGA, and FTIR, to explore the surface morphology, thermal stability, and the presence of functional groups on the fly ash surface, respectively. The two modified forms of fly ash were also experimented to test their efficiency for the removal of two non-polar organic pollutants chloro- and nitrobenzene from aqueous phase. Different parameters like effect of adsorbent dose, pH of solution, temperature, adsorbent interaction time and initial conc. of solution were also studied. The analysis results showed SDS modified fly ash is superior than HDTMA modified fly ash. The maximum uptake capacity of chlorobenzene and nitrobenzene with SDS-modified fly ash (SFA) is 200 mg/g and 70mg/g respectively. The adsorption of chlorobenzene is exothermic over both adsorbents while nitrobenzene showed the endothermic behavior. The isotherm analysis depicted the multilayer adsorption of both pollutants onto the surface of surfactant modified ash.