No abstract

The adsorption process of methylene blue (MB) and its removal from aqueous solution at initial pollutant concentration range of 1–7 ppm was investigated. Zeolite-A (Z) and its ZnO-loaded species (Z/ZnO) were prepared via microwave technique from natural resource and applied for dye removal. The loading of ZnO was governed by the cation exchange property of zeolite, followed by calcination. Experimentally, Z and Z/ZnO were tested using X-ray Diffraction (XRD), Fourier-Transform Infrared (FTIR), Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDX) and N2 adsorption-desorption. The examined parameters such as concentration of dye, contact time, ZnO dose and solution pH were traversed. Three isothermal models were analyzed. Kinetic studies indicated that, the adsorption of MB matched with pseudo-second order model. The maximum removal efficiency at pH 3, increased from 67.8% for Z to 94.8% for Z/ZnO modified with 3% ZnO loads (Z/ZnO(3%)). Parameters such as ΔH, ΔS, ΔG, S* and Ea were thermodynamically calculated. Langmiur isotherm and pseudo-second order models were the best fitting for the obtained data. The results indicated that, the adsorption of MB dye is spontaneous and endothermic, the removal efficiency is favored by increasing the temperature. ZnO-zeolite has much higher adsorption capacity for eliminating MB dye than that of the un-loaded zeolite.

The present study reports the feasibility of the synthesis of a novel porous activated carbon (OS400) composite adsorbent prepared from olive stone and impregnated with garnet (GA) types of black sand minerals. The Activated Carbon/ garnet composite (OSMG) was applied for the sorption of macromolecular organic dye. The structural characteristics of the synthesized composite were evaluated by Brunauer–Emmett–Teller (BET), N2 adsorption/desorption measurements, Scanning Electron Microscopy equipped with Energy Dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD), and a Fourier transform infrared spectrometer (FT-IR). The specific surface area of (GA), (OS400), and (OSMG) were 5.157 m2.g− 1, 1489.598 m2.g− 1, and 546.392 m2.g− 1, respectively. The high specific surface area and effective active centers of the new composite promoted the adsorption of methylene blue (MB). The experiments were carried out under various conditions such as contact time, initial concentration of adsorbate, adsorbent dosage, pH, and temperatures. The equilibrium adsorption data were evaluated using the Langmuir and Freundlich isotherm models. The results display that, the adsorption isotherm had an excellent fitting to the Freundlich model. Furthermore, the data obtained from adsorption kinetic models showed that the pseudo-second-order model more agreeing for describing the (MB) adsorption reaction, suggesting a chemisorption mechanism. The values of thermodynamic parameters indicate that methylene blue dye adsorption onto the (GA) adsorbents through an endothermic reaction, while exothermic sorption of MB onto (OS400) and (OSMG), with a non-spontaneous process.

A Novel and sustainable chitosan (CS)/ activated charcoal (AC) composites were prepared by cross linking with epichlorohydrine (ECH) to form a porous structure. Different titanium dioxide nanoparticles (TiO 2 NPs) concentrations (0, 0.2, 0.4, and 0.8% w/w) were added to enhance the photocatalytic, antibacterial, larvicidal, and pupicidal activities e ciency toward rose bengal (RB) dye and the Culex Pipiens. The composites were characterized by FT-IR, XRD and SEM. The SEM images revealed the porous structure of CS/AC and TiO 2 nanoparticles were uniformly distributed in the CS/AC matrix. The degradation of RB dye was used to test the photocatalytic behavior of the composites. Supporting TiO 2 on a CS/AC matrix resulted in a signi cant increase in photocatalytic performance. The antibacterial activities supported by CS/AC/TiO 2 NPs were evaluated by bacterial growth inhibition against B. subtilis, S. aureus, E. coli and P. aeruginosa. The results showed that CS/AC/TiO2 NPs composite has an inhibitory effect and therefore considered as antibacterial agents. CS/AC/0.4%TiO 2 NPs showed maximum e cacy against larvicidal activity and pupicidal of mosquito vector which recorded 99.00 ± 1.14, 95.00 ± 1.43, 92.20 ± 2.64 for rst, second and third larval instars and 66.00 ± 2.39 for pupal mortality, while the repellent activity reported high protection at 82.95 ± 2.99 with 3.24 mg/cm 2 dose compared to control DEET.

Commercial Granulated Active Carbon (GAC) has been modified using 10 Gy dose Gamma irradiation (GAC10 Gy) for increasing its ability of air purification. Both, the raw and treated samples were applied for removing Chlorpyrifos pesticide (CPF) from ambient midair. Physicochemical properties of the two materials were characterized by Fourier Transform Infrared (FT-IR) and Raman spectroscopy. The phase formation and microstructure were monitored using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), supported with Energy-Dispersive X-ray (EDX). The Surface area measurement was detected using BET particle size prosometry. Obtained outcomes showed that, the maximum adsorption capacity, given by Langmuir equations, was greatly increased from 172.712 to 272.480 mg/g for GAC and GAC10 Gy, respectively, with high selectivity. The overall removal efficiency of GAC10 Gy was notably comparable to that of the original GAC-sorbent. The present study indicated that, gamma irradiation could be a promising technique for treating GAC and turned it more active in eliminating the pesticides pollutants from surrounding air. The data of equilibrium has been analyzed by Langmuir and Freundlich models, that were considerably better suited for the investigated materials than other models. The process kinetics of CPF adsorbed onto both tested carbon versions were found to obey the pseudo first order at all concentrations with an exception at 70 mg/l using GAC, where, the spontaneous exothermic adsorption of Chlorpyrifos is a strong function for the pseudo-first order (PFO) and pseudo second order (PSO) kinetics.