Optimization and Computational Approach to Understand the Adsorption Behavior of Alizarine Red S on the Surface of Fish Scales

The key components of fish scales are hydroxyapatite and collagen, which form a natural composite. In this present study, fish scales were used as biosorbent to uptake Alizarine Red S dyes from the wastewaters. Here, dye concentration, adsorbent amount, pH, and temperature were optimized using complete factorial design analysis. Sixteen experiments were required, and a linear mathematical model representing the influence of the different variables and their interactions was obtained. The discussion covered analysis of variance (ANOVA), normal probability plots of residuals, and surface plots. Theoretical calculations by Metropolis Monte Carlo (MC) methods, the density functional theory (DFT), and the electrostatic potential surface (ESP) analysis were achieved to obtain a more understanding of the dyes adsorption mechanism on both collagen and hydroxyapatite (HDA) surfaces. The findings results exhibited that the ARS dye presents more tendency of adsorption on the collagen than on the HDA surface.

Tensile properties of polypropylene/linear low-density polyethylene/nano-titanium dioxide nanocomposites using a two-level factorial experiment

In this paper, a 23 factorial design analysis was used to study the parameters affecting the mechanical characteristics of polypropylene/linear low-density polyethylene/nano-titanium dioxide (PP/LLDPE/TiO2) nanocomposites, and to optimize these factors in order to predict the maximum ultimate tensile strength (UTS), elastic modulus (EM), and yield strength (YS) simultaneously. To do this, two levels of nano-titanium dioxide (TiO2), linear low-density polyethylene (LLDPE) and styrene-ethylene-butylene-styrene (SEBS) as the coupling agent were selected and eight experiments were conducted for every response. The most effective factors influencing the UTS, EM, and YS were found, and acceptable prediction regression models were taken. One noted that nanoparticles increased the elastic modulus. The attendance of high levels of LLDPE and SEBS resulted in a decrease in YS and UTS. Moreover, the optimum values of variables were determined by using the contour plot.