Zinc oxide nanorod‐loaded activated carbon for ultrasound‐assisted adsorption of safranin O: Central composite design and genetic algorithm optimization

Abstract

This paper focuses on the development of an effective methodology to obtain the optimum ultrasonic‐assisted removal of a dye, safranin O (SO), under optimum conditions that maximize the removal percentage, using ZnO nanorod‐loaded activated carbon (ZnO‐NRs‐AC) in aqueous solution. Central composite design coupled with genetic algorithm was used for parameter optimization. The effects of variables such as pH, initial dye concentration, mass of ZnO‐NRs‐AC and sonication time were studied. The interactive and main effects of these variables were evaluated using analysis of variance. The structural and physicochemical properties of the ZnO‐NRs‐AC adsorbent were investigated using field emission scanning electron microscopy and X‐ray diffraction. Adsorption equilibrium data were fitted well with the Langmuir isotherm and the maximum monolayer capacity was found to be 32.06 mg g−1. Studies of the adsorption kinetics of the SO dye showed a rapid sorption dynamic with a pseudo‐second‐order kinetic model, suggesting a chemisorption mechanism.

Fe3O4-Based Melamine-Rich Covalent Organic Polymer for Simultaneous Removal of Auramine O and Rhodamine B

“…The Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherm models at three different temperatures of 296, 306, and 316 K were employed to explore the equilibrium data for the adsorption of AO and RB onto Fe 3 O 4 /C–COP, according to previous reports. ,, The equations and amounts of the various parameters of these four isotherm models are represented in Table . The plots of the mentioned isotherms are signified in Figure and the results exhibit that the equilibrium data with R 2 > 0.99 and the maximum adsorption capacities of 107.11 (AO) and 131.23 (RB) mg/g fit well with the Langmuir adsorption isotherm.…”

“…Finally, Fe 3 O 4 /C–COP was separated from the solution by an external magnet, and the final absorption of nonadsorbed AO and RB content was determined using an ultraviolet–visible spectrophotometer. The removal capacity, q e (mg/g), and removal percentage were calculated according to previous reports. ,, …”

“…Although various wastewater treatment techniques have been developed, − most of these techniques do not entirely remove pollutants, while they also produce risky byproducts, and are expensive. The adsorption of these pollutants is the best process because it is economical, environmentally benign, requires easy operation, has a simple design, and does not cause production of contaminant byproducts among others. − The adsorbent selection has a key role in the adsorption, and a variety of adsorbents such as carbon-based materials, metal oxide (MO) nanoparticles, hydrogels, metal sulfides and selenides, dendrimers, polymeric nanocomposites, lignin–chitosan, metal–organic frameworks (MOFs), , and covalent organic frameworks (COFs) , have been utilized to remove the dyes from aqueous media.…”

Carbon based materials: a review of adsorbents for inorganic and organic compounds

“…Efficiency of separation increased following the application of AC fibers as molecular sieves in gas filtration, which emerged from the fact that AC fiber shapes often have a greater adsorption rate and a larger capacity than typical granular ACs. Also, several research studies on the modification of AC by nanoparticle (NP) surfaces have been carried out for the creation of specific surfaces to enhance the removal of chemical species, including Bi 2 S 3 -Ag 2 S, 61 CrFeO 3 , 62 ZnO, 63 Au-Fe 3 O 4 , 64 ZnS:Cu, 65 Pt, 66 Cu 2 O, 67 Cu:ZnS, 68 4.…”

Characterization and photocatalytic activity of ZnO nanoflowers synthesized using Bridelia retusa leaf extract

“…Different types of dyes are discharged from various industries which make undesirable impacts on living beings (Chakraborty et al 2020). It is essential to remove these dyes from wastewater before entry into water bodies (Sharifpour et al 2018). Among various dye-removal technologies, a popular technique is advanced oxidation process (AOP) that relies on highly reactive oxidants to destroy organic pollutants till their mineralization produces CO 2 and H 2 O as end products.…”