Insight into the Technical Qualification of the Sonocogreen CaO/Clinoptilolite Nanocomposite (CaO(NP)/Clino) as an Advanced Delivery System for 5-Fluorouracil: Equilibrium and Cytotoxicity.

Clinoptilolite as a natural zeolite was integrated with green CaO nanoparticles forming the green nanocomposite CaO(NP)/Clino. The CaO(NP)/Clino composite was assessed as a potential carrier for 5-fluorouracil (5-FL) drug. The CaO(NP)/Clino carrier achieved an enhanced 5-FL loading capacity of 305.3 mg/g as compared to 163 mg/g for pure clinoptilolite. The kinetics of the 5-FL loading follow the properties of the pseudo-first-order model, while the equilibrium results are related to the Langmuir isotherm. Therefore, the 5-FL loading processes occurred in the monolayer formed by homogeneous active loading receptors on the surface of the CaO(NP)/Clino carrier. The Gaussian energy of the 5-FL loading reaction (9.2 KJ/mol) reflected the dominant effect for the chemical mechanisms, especially the zeolitic ion-exchange mechanisms. Additionally, the thermodynamic parameters suggested endothermic, feasible, and spontaneous properties for the occurred 5-FL loading reactions. The release profile of 5-FL from CaO(NP)/Clino has continuous and long properties (150 h) at pH 1.2 (gastric fluid) and pH 7.4 (intestinal fluid). The kinetic studies of the release reactions show considerable agreement with Higuchi, Hixson-Crowell, and Korsmeyer-Peppas models. Such high fitting results and the diffusion exponent values (0.49 at pH 1.2 and 0.48 at pH 7.4) reflected the release properties of the Fickian transport behavior involving complex erosion and diffusion mechanisms. The cytotoxicity study of CaO(NP)/Clino on colorectal normal cells (CCD-18Co) declare the safe and biocompatible effect as a carrier for the 5-FL drug. Additionally, CaO(NP)/Clino as a carrier causes considerable enhancement for the cytotoxic effect of the loaded 5-FL drug on colon cancer cells (HCT-116).

Effective decontamination of Ca2+ and Mg2+ hardness from groundwater using innovative muscovite based sodalite in batch and fixed-bed column studies; dynamic and equilibrium studies.

A novel form of sodalite was synthesized from muscovite (M.SD) as low-cost softening material for both Ca2+ and Mg2+ ions from real groundwater in batch and column studies. The sodalite sample showed significant surface area (105 m2/g) and ion exchange capacity (87.3 meq/100 g) which qualifies it strong for softening applications. The incorporation of the M.SD as a fixed bed in column system at a fixed thickness of 4 cm and flow rates of 5 mL/min resulted in removal percentages of 90.5% and 92.2% for Ca2+ and Mg2+, respectively at pH 7.6. Considering the real concentrations of the ions (Ca2+ (233 mg/L) and Mg2+ (114 mg/L)), the M.SD bed has the ability to reduce their concentrations according to the recommended limits (75 mg/L for Ca2+ and 50 mg/L for Mg2+). These conditions resulted in purification of about 8.1 L and 8.7 L with breakthrough intervals of 1380 min and 1440 min; and saturation interval more than 1620 min for Ca2+ and Mg2+, respectively. The M.SD columns' performances were described considering the assumption of the Thomas model, Adams-Bohart model, and Yoon-Nelson model. The batch studies demonstrate the uptake of both Ca2+ and Mg2+ ions according to the Pseudo-First order kinetics and Langmuir equilibrium behaviour. Considering the values of Gaussian energies (0.77 KJ/mol (Ca2+) and 1.36 KJ/mol (Mg2+)), the uptake of these ions occurred by homogenous reactions of monolayer form and physical nature. The thermodynamic studies declared the spontaneous properties of the reactions and their exothermic properties.

Promoting the decontamination of different types of water pollutants (Cd2+, safranin dye, and phosphate) using a novel structure of exfoliated bentonite admixed with cellulose nanofiber.

Exfoliated bentonite sheets admixed with nano-cellulose fibers (EXB/CF) were prepared as advanced bio-composite of enhanced decontamination properties for different species of water pollutants (Cd2+, safranin dye, and phosphate). The composite achieved promising adsorption capacities with experimental values of 206.8 mg/g (Cd2+), 336 mg/g (safranin), and 296 mg/g (phosphate); and predicted maximum capacities of 212.9 mg/g (Cd2+), 341 mg/g (safranin), and 305 mg/g (phosphate). The adsorption systems for the three species follow the Freundlich isotherm model and Pseudo-First order as kinetic model considering both the linear and nonlinear fitting demonstrating heterogeneous and multilayer uptake properties of physisorption type. The operation of physisorption mechanisms was supported by the obtained adsorption energies from D-R model that are less than 8 kJ/mol as well as the calculated free energies and enthalpies. The thermodynamic investigation revealed the nature of the adsorption reactions of the three pollutants by EXB/CF as exothermic, favorable, and spontaneous reactions. The EXB/CF composite also is of significant recyclability value and applied in five decontamination reusing runs for Cd2+, safranin dye, and phosphate achieving promising removal percentages.

Insight into the Adsorption and Photocatalytic Behaviors of an Organo-bentonite/Co3O4 Green Nanocomposite for Malachite Green Synthetic Dye and Cr(VI) Metal Ions: Application and Mechanisms.

A green composite of organically modified bentonite supported by Co3O4 nanoparticles (OB/Co) was successfully fabricated and investigated as a potential eco-friendly, low-cost adsorbent and photocatalyst for promising removal of both malachite green dye (MG.D) and Cr(VI) ions. The composite showed high adsorption properties and achieved experimental q max values of 223 and 139 mg/g for MG.D and Cr(VI) after equilibration times of 360 min and 480 min for the inspected contaminants, respectively. The kinetic and equilibrium inspection reflected the best description of their adsorption behaviors by the pseudo-first-order kinetic model and the Langmuir isotherm model, respectively. This revealed favorable and homogeneous uptake of both MG.D and Cr(VI) in a monolayer form with theoretical Langmuir q max values of 343.6 and 194.5 mg/g, respectively. The theoretical adsorption energies of MG.D (0.6 kJ/mol) and Cr(VI) (0.5 kJ/mol) from the Dubinin-Radushkevich (D-R) model revealed physisorption properties that might be resulted from some types of Coulombic attractive forces, achieving theoretical q max values of 226.5 and 144.6 mg/g, respectively. The suggested adsorption mechanism was confirmed by the main mathematical parameters of thermodynamic studies that revealed physical, spontaneous, and exothermic uptake processes. Also, the composite showed high photocatalytic performance under visible light, which resulted in a 100% removal percentage of 100 mg/L of MG.D and Cr(VI) after about 180 and 240 min, respectively, from the adsorption equilibrium time.

Facile conversion of kaolinite into clay nanotubes (KNTs) of enhanced adsorption properties for toxic heavy metals (Zn2+, Cd2+, Pb2+, and Cr6+) from water.

Kaolinite nanotubes (KNTs) were synthesized from kaolinite by ultrasonic scrolling and characterized using X-ray diffractometer, scanning and transmission electron microscopes; and FTIR-FT Raman spectrometer. The synthetic KNTs appear as multi-walled scrolls of 12 nm average pore diameter and 50-600 nm particle length; and exhibit surface area of 105 m2/g. KNTs were used as adsorbents for Zn2+, Cd2+, Pb2+, and Cr6+ with uptake capacities of 103 mg/g, 116 mg/g, 89 mg/g, and 91 mg/g, respectively. The equilibration time of Cd2+ and Pb2+ adsorption is 360 min and for Cr6+ and Zn2+ area 120 min and 240 min, respectively. KNTs adsorption systems can be described mainly by Lagergren-second order and Freundlich models (R2> 0.95) as kinetic and isotherm models. This reflected multilayer adsorption forms with chemical sharing or ion exchange processes. KNTs exhibits high reusability and used for five cycles in the removal of the studied metals (100 mg/L). The removal percentages declined by 20.5%, 15.12%, 22.8% and 23.16% with repeating the reused cycles from cycle 1 to cycle 5 for Zn2+, Cd2+, Pb2+, and Cr6+, respectively. KNTs were applied successfully in realistic purification of tap water, groundwater, and sewage water from the inspected metals.

Green fabrication of bentonite/chitosan@cobalt oxide composite (BE/CH@Co) of enhanced adsorption and advanced oxidation removal of Congo red dye and Cr (VI) from water.

Bentonite/chitosan composite supported by green fabricated Co3O4 was successfully synthesized and its physicochemical properties were investigated utilizing several analytic techniques. The formation of the composite was confirmed by the XRD patterns, SEM, HRTEM images, and FT-IR analysis. The adsorption properties of bentonite/chitosan@Co3O4 for acidic dye (Congo red) and Cr(VI) ions were investigated. The kinetic studies reflected the saturation of the composite surface after 480 min for both Congo red molecules and Cr(VI) ions. Additionally, the systems are of chemisorption nature and showed excellent fitting with Pseudo-second order model. The mathematical parameters of the isotherm models revealed a monolayer uptake of Congo red molecules and Cr(VI) ions and represented mainly by the Langmuir model. The theoretical calculated maximum adsorption capacity (qmax) is 303 mg/g and 250 mg/g for Congo red molecules and Cr(VI) metal ions, respectively. The composite is of high reusability and can be used effectively for six runs of decontamination of Congo red molecules and Cr(VI) ions. Moreover, it is of high oxidation properties and can be used in the photocatalytic reduction of Congo red molecules and Cr(VI) ions from water. Besides that, bentonite/chitosan@Co3O4 green composite was used in purification of realistic water samples which make it one of the promising adsorbents.