Sharif Digital Repository

The functionalized copper oxide–zinc oxide nanocomposite (FCZN) was synthesized and characterized using Fourier transform infrared, scanning electron microscopy, X-ray diffraction, X-ray fluorescence, and BET. Dye removal from aqueous solution was done in a batch system using FCZN as an adsorbent. The effects of adsorbent dosage, initial dye concentration, pH, temperature, and additive salts on dye removal were investigated. Isotherms, kinetics, and thermodynamics of dye adsorption were studied. Equilibrium and kinetic data were fitted by Langmuir isotherm and pseudo-second-order kinetic, respectively. The thermodynamic data showed that dye adsorption was spontaneous, endothermic, and... 

Retention of lead(II) ions on a polyamide nanofiltration membrane was investigated. Effects of different factors including operating pressure, lead ion concentration, anion nature, pH and composition of feed on the lead ion rejection were studied. The solutions used consisted of Pb(NO3)2, PbCl2 and PbSO4 in the single-salt solution system and Pb(NO3)2, Cu(NO3)2, Zn(NO3)2, Cd(NO3)2, NaNO3 and NH4NO3 in the binary-salt solution system. The influence of divalent and monovalent cations including cadmium, copper, zinc, sodium and ammonium on the rejection of lead ion was examined. The transmembrane pressure and lead ion concentration varied between 10 and 40bar and 20 and 400mg Pb2+/L,... 

This article investigates phenol removal from an aqueous solution by using enzymatic and photocatalytic methods and the efficiency of these methods has been compared. In enzymatic and photocatalytic methods, Coprinus cinereus, peroxidase enzyme and commercial TiO2 powders (Degussa P-25) in aqueous suspension were used, respectively, in ambient temperature. The effects of different operating parameters such as duration of process, catalyst dosage or enzyme concentration, pH of the solution, initial phenol concentration and H2O2 concentration on both processes were examined. In enzymatic method, efficiency of degradation reached 100% within 5min, while in the photocatalytic method, the... 

This study investigated the diesel and COD removal from oily wastewater by electrocoagulation. Experiments were conducted in a 2-l reactor using aluminum and iron electrodes. Effects of different parameters including pH (3–11), time (10–60 min), voltage (4.5–10.5 V), supporting electrolyte (NaCl concentration), electrode material and initial diesel concentration (3500–11,000 mg/L) were studied in order to evaluate the efficiency of electrocoagulation. Furthermore, the consumption of energy and the amount of sludge produced by this method were evaluated. The highest removal efficiency (COD removal of 99.1 ± 0.2 % and diesel removal of 98.8 ± 0.2 %) was observed under the following conditions:... 

Fungal delignification can be considered as a feasible process to pre-treat lignocellulosic biomass in biofuel production, if its performance is improved in terms of efficiency thorough a few modifications. In this study, Trichoderma viride was utilized to investigate the effect of wet-milling, addition of surfactant (Tween 80) and optimization of operating factors such as temperature, biomass to liquid medium ratio and glucose concentration on biodelignification of rice straw. Next, the enzymatic hydrolysis of pretreated biomass was studied at various pretreatment times. Results revealed that the wet milling and addition of surfactant increases the lignin removal about 15% and 11%,... 

The conventional one-factor-at-a-time (OFAT) method and two statistical methods including factorial design and response surface methodology (RSM) were applied for optimization of reactive blue 221 (RB221) decolorization using Coprinus cinereus peroxidase (CIP). Through the OFAT analysis the optimal conditions was at the temperature of 22 oC, pH 9.0, H2O2 concentration of about 4.258mM and initial dye concentration of 80ppm for the 100% decolorization of RB221in only 30seconds. In the statistical analysis, factorial design method was primarily applied for screening the most significant parameters on RB221 decolorization. Then two stage optimization using RSM was performed through central...