Isothermal and Batch Adsorption Studies of Malachite Green Oxalate Dye onto Activated Carbon from Snail Shell

Adsorption efficiency, kinetic and thermodynamic studies of the adsorption of Malachite green oxalate onto activated carbon from snail shell was carried out. The cleaned Snail shell was carbonized at 400oC, crushed and sieved before it was activated with 0.1m HCl at 800oC in a furnace. Batch adsorption experiment was carried out at variable concentration, time and temperature while other factors are kept constant. The adsorption isotherms used show that the correlation coefficient of Freundlich isotherm is closer to unity compare to that of Langmuir isotherm. The adsorption follows the Pseudo second order kinetic with adsorption capacity of 1.7544 (mg/g) and rate constant of 0.471(g/mg.min). The thermodynamic parameters: change in enthalpy, ∆H = 15.90 KJ/mol, change in entropy ∆S = 60.16J/mol. K and the change in Gibbs free energy ∆G = -1.69, -2.98, -3.64, -3.24, -3.43 and -3.51 KJ/mol at 303, 308, 313, 318, 323 and 328K respectively. These results show that activated carbon from snail shell has the potential of a good low cost adsorbent for the removal of this hazardous dye from wastewater

Equilibrium Isotherm, Kinetic and Thermodynamic Studies of the Adsorption of Erythrosine Dye onto Activated Carbon from Coconut Fibre

Equilibrium isotherm, kinetic and thermodynamic studies of the adsorption of erythrosine dye onto activation carbon from coconut fire was carried out. The coconut fibre obtain from Elele, Rivers State Nigeria, was washed, dried, carbonized at 400oC, crushed, sieved and activated at 800oC, before it was washed and dried at 110oC. Variable influencing factors, such as contact time, temperature and initial concentration were studied through single-factor experiment, while other factors are kept constant (at 30min, 30oC and 50mg/L) in each adsorption experiment. The Freundlich isotherm fits adsorption compare to others used, the adsorption kinetic followed pseudo-second order reaction, while the thermodynamic parameters, (∆H) = 28.73KJ/mol, (∆G) = 94.45J/mol.K and (∆S) = -0.10, -0.27, -0.82, -1.05, -1.77, -2.49KJ/mol. From the results obtained, activated carbon from coconut fibre, will be an excellent low-cost adsorbent for the removal of Erythrosine from industrial waste water

Statistical Modeling and Optimization of Biodiesel Production from Azadirachta Indica (Neem) Using Co-Solvent Technique

In this work, statistical modeling and optimization of biodiesel production from Azadirachta Indica(neem) using co-solvent technique via a two-step transesterification process was carried out. Neem oil was extracted from neem seeds and properties such as moisture content, specific gravity, acid value, saponification value and iodine value were determined. The experimental design used was Central Composite Design. The range of factor levels used for the Central Composite Design were reaction temperature (30°C to 46°C), catalyst amount (0.8% to 1.2%, w/w), reaction time (20 to 40min) and methanol-to-oil molar ratio (5:1 to 9:1). The co-solvents used were methanol and diethyl ether. The co-solvent-to-methanol volume ratio for all the experimental runs was kept constant at 1:1. Also the biodiesel produced was characterized for some important properties including acid value, specific gravity, saponification value, iodine value, cetane number, ester value, kinematic viscosity, flash point, pour point and cloud point. Optimized biodiesel yield of 84.77% was obtained for reaction time of 35 min, catalyst amount of 1.10g, reaction temperature of 34°C, and oil-to-methanol molar ratio of 6:1. The cetane number (51.733), specific gravity (0.8881g/cm3), flash point (134oC) and kinematic viscosity (5.86mm2/s) of the produced biodiesel met the ASTM specifications. The results of characterization of the biodiesel revealed that biodiesel can be produced at lower reaction conditions and with comparable fuel property with biodiesel produced using conventional methods