Statistical optimization was used to optimize corrosion inhibition efficiency of Sapium ellipticum leaf extract as corrosion inhibitor of aluminum in acid medium. Response surface methodology was applied, and the effects of four independent variables; acid concentration, inhibitor concentration, temperature, time, and their expected responses were determined. Central composite design a statistical tool was used to generate a total of 16 individual experimental runs, which was previously design to study the effects of these variables during corrosion process. The uniqueness of the model was scrutinized with various criteria including coefficient of determination (R2 = 0.987), p value (< 0.0001), adequate precision (30.22) and coefficient of variation (5.30). The RSM is well fitted in the model which adequately predicted the optimum inhibition efficiency of 96.73% at optimum inhibitor concentration of 1.5g/L-1, acid concentration 1 M, temperature of 303 K and time of 6 hours. Also the electrochemical concept signifies that Sapium ellipticum acts as a mixed-kind inhibitor. The experimental data obtained is in conformity with other research works.
Bull. Chem. Soc. Ethiop. 2020, 34(1), 175-191.
DOI: https://dx.doi.org/10.4314/bcse.v34i1.17
Adsorption potential of periwinkle shell (PRW), an agricultural waste, for the removal of phosphate from aqueous solution was investigated through equilibrium studies at various experimental conditions. PRW was carbonized and chemically activated with 1MH 2 SO 4 before it was subjected to characterization using Fourier Transform Infrared (FT-IR), Energy Dispersive X-ray (EDX) and Scanning Electron Microscopy (SEM). Adsorption data were analyzed using various kinetic and isotherm models. Statistical modeling through Central Composite Design (CCD) was also employed. The results showed that, FT-IR spectrum of the activated PRW shows many absorption peaks and a variety of functional groups such as -OH, -NH, C = O, C-H, C-N, CH 3 and CH 2 which explains its improved adsorption behavior on the colloidal particles. SEM shows the morphological changes with respect to the shape and sizes of the adsorption sites.EDX indicates the higher percentage composition of carbon (11.66%), Oxygen (63.18%) as important constituent elements for adsorption. Equilibrium data were well fitted to pseudo second order kinetic model and were best described by Langmuir Isotherm model at the temperature of 303K. Removal efficiency of 95.90% was obtained. A statistical model equation was developed for the adsorption process which reveals contact time as the most significant main effect for performance of the adsorbent.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.