Combined Minimum-Run Resolution IV and Central Composite Design for Optimized Removal of the Tetracycline Drug Over Metal–Organic Framework-Templated Porous Carbon

Abstract

In this study, a minimum-run resolution IV and central composite design have been developed to optimize tetracycline removal efficiency over mesoporous carbon derived from the metal-organic framework MIL-53 (Fe) as a self-sacrificial template. Firstly, minimum-run resolution IV, powered by the Design–Expert program, was used as an efficient and reliable screening study for investigating a set of seven factors, these were: tetracycline concentration (A: 5–15 mg/g), dose of mesoporous carbons (MPC) (B: 0.05–0.15 g/L), initial pH level (C: 2–10), contact time (D: 1–3 h), temperature (E: 20–40 °C), shaking speed (F: 150–250 rpm), and Na+ ionic strength (G: 10–90 mM) at both low (−1) and high (+1) levels, for investigation of the data ranges. The 20-trial model was analyzed and assessed by Analysis of Variance (ANOVA) data, and diagnostic plots (e.g., the Pareto chart, and half-normal and normal probability plots). Based on minimum-run resolution IV, three factors, including tetracycline concentration (A), dose of MPC (B), and initial pH (C), were selected to carry out the optimization study using a central composite design. The proposed quadratic model was found to be statistically significant at the 95% confidence level due to a low P-value (<0.05), high R2 (0.9078), and the AP ratio (11.4), along with an abundance of diagnostic plots (3D response surfaces, Cook’s distance, Box-Cox, DFFITS, Leverage versus run, residuals versus runs, and actual versus predicted). Under response surface methodology-optimized conditions (e.g., tetracycline concentration of 1.9 mg/g, MPC dose of 0.15 g/L, and pH level of 3.9), the highest tetracycline removal efficiency via confirmation tests reached up to 98.0%–99.7%. Also, kinetic intraparticle diffusion and isotherm models were systematically studied to interpret how tetracycline molecules were absorbed on an MPC structure. In particular, the adsorption mechanisms including “electrostatic attraction” and “π–π interaction” were proposed.

Operational parameters optimization for remediation of crude oil-polluted water in floating treatment wetlands using response surface methodology

“…In this design, the central points are augmented with a group of axial points, also known as star points. With this design, first-order and second-order terms can be estimated quickly 26 – 29 . Previously, several wastewater remediation processes have been optimized with RSM for maximum removal of organic and inorganic pollutants from wastewater 30 – 32 .…”

Process Optimization by a Response Surface Methodology for Adsorption of Congo Red Dye onto Exfoliated Graphite-Decorated MnFe2O4 Nanocomposite: The Pivotal Role of Surface Chemistry

“…Meanwhile, residuals versus run plots in Figure 7a,b illustrate relatively random scatters, proposing that the variance values are the constants against the residuals variables. At the same trend, Figure 8a,b show predicted and actual points distributed on the 45-degree line, therefore, it is reliable to predict the trends of models [47,48]. Three-dimensional surfaces and contour plots as shown in Figures 9-11 reflect the effect of parameters on the response [49].…”

Amino-functionalized MIL-88B(Fe)-based porous carbon for enhanced adsorption toward ciprofloxacin pharmaceutical from aquatic solutions

“…This hypothesis was evidenced by the better performance of N-doped porous carbon toward nitrogen-containing compounds (e.g., indole and quinoline) and sulfur-containing compounds (e.g., benzothiophene and dibenzothiophene) in comparison with the cases of N-free porous carbons [10,14,54]. Based on the aforementioned findings, we argue that the porous carbon from N-containing MOFs may rely mostly on the N species to create more H-bonding interaction, showing higher adsorption efficiency [55]. By this way, the amino functionalization can become an efficient approach for the liquid-phase adsorption to purify water and fuel.…”