الملخص الإنجليزي
Activated and dehydrated carbons were prepared from mandarin peel (Citrus reticulata) MP Activated carbon (AC) was prepared at using NaOH activation at 700 oC. AC was oxidized using nitric acid to produce oxidized activated carbon (OAC). Dehydrated carbon was prepared at 180 oC using sulfuric acid (SDC) or phosphoric acid (PDC). Surface area was found to be 645.5, 388.5, 14.6 and 7.4 m2/g for AC, OAC, SDC and PDC, respectively. Ag+ sorption was tested at different pH, contact time, concentration and temperature. Ag+ loading was low at low pH and maximum performance was found at initial pH of 6. Equilibrium was reached within 72 hours for all carbons with sorption kinetics data fitting a pseudo second order model and increased performance as temperature rises. Equilibrium sorption data shows an L-type isotherm with sorption data fitting the Langmuir isotherm model more than the Freundlich isotherm model with better sorption as temperature rise. X-ray diffraction and SEM confirmed the presence of silver particles precipitated on the surface of all carbons. Cumulative silver loading was carried out 3 consecutive runs for more loading of silver. Ag+ showed higher sorption reaching 630, 972, 755 and 589 mg/g for AC, OAC, SDC and PDC respectively by the third consecutive run. Silver loaded carbons from cumulative sorption were tested for antibacterial properties for E.coli, S.aureus and P.aeruginosa bacteria. All carbons showed effective antibacterial effects in inhibition zone and growth inhibition.
