English abstract
A sample of brackish water collected from a farm well in Barka was analyzed and showed an elevated levels of total dissolved solids (TDS) with abundant ions including Nat(558 mg/L), Ca2+(251 mg/L), Mg2+(156 mg/L), CF(1434 mg/L), SO42-+(373 mg/L) and NO3- (35 mg/L).
Dehydrated carbon (DC) that was prepared from date palm leaflets using sulfuric acid, was functionalized successfully to produce a cation exchanger of sulfonated dehydrated carbons (SDC) and an anionic exchanger of basic dehydrated carbon (BDC). SDC is acidic and acts as a cationic exchanger while BDC acts as an anionic exchanger. SDC and BDC possess less surface area with high contents of surface functional groups. Kinetic study showed that equi-librium was obtained within 2 hours from synthetic solutions and brackish water with data fitting the pseudo second order model. SDC showed good performance for Nat sorption (29.1 mg/g) while BDC showed best sorption performance for CI (28.2 mg/g). Sorption of Nat and CI was enhanced in the presence of both sorbents (Nat 36.9 mg/g, Cl56.8 mg/g). The equi-librium data were found to fit more the Langmuir model than the Freundlich model. Sorption preference from ionic mixture of equal metal concentrations (mg/L) followed the order: Ca2+> Mg2+> Nat and for the anions: NO3'>SO42-> C1'. Nat and cr showed desorption phenomenon in the presence of other ions in sorption solution. Efficiency of ions removal has in creased with sorbent mass increase. Combined sorbents showed better sorption capacity for both cations and anions with efficient recycle properties. The study showed that a combined filter of both SDC and BDC show promising desalting properties of brackish water in addition of being cheap, recyclable and sustainable.
