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In this study, polypyrrole (PPy) was introduced into durian rind (DR) by in situ polymerization method to prepare durian rind/polypyrrole (DR/PPy) composite. The resulting material was characterized using scanning electron microscope (SEM), transmission electron microscope (TEM), infrared spectroscopy (IRS), and X-ray diffraction (XRD). Then, the removing performance of the DR/PPy material for anionic dyes was explored. The impact of key variables such as the amount of adsorbent, initial dye concentration, pH, adsorption temperature, and contacting time on the adsorption efficiency was examined. The result disclosed that the adsorption efficiency of DR/PPy for methyl orange, sunset yellow, and amaranth was satisfactory. In pH of 7, initial concentration of 100 μ g mL-1, and DR/PPy dosage of 1.5 g L-1, the removal efficiency reached 97.31%, 98.48%, and 98.20%, respectively. The adsorptive kinetics and thermodynamic process were analyzed subsequently. The adsorption of anionic dyes on DR/PPy conforms to the pseudo-second-order kinetic and Langmuir isotherm models with maximum adsorption capacity ( q m , max ) of 193.05, 171.23, and 147.71 mg g-1 for methyl orange, sunset yellow, and amaranth, respectively. Finally, a possible mechanism involved in the adsorption system was put forward. This study implies a reasonable feasibility for the effective utilization of waste to control the pollution. [ABSTRACT FROM AUTHOR]

p -sulphonated calix[4]arene (p -SOCX) functionalized cellulose acetate/graphene oxide (CA/GO) nanofibers were successfully prepared via the electrospinning technique. The presence of p -SOCX within the fiber matrix was ascertained using Fourier Transform Infrared spectroscopy and Carbon-Hydrogen-Nitrogen-Sulphur elemental analyses. Apparent changes in morphology of the samples were observed under scanning electron microscope where fiber diameters increased with increasing p -SOCX content. Preliminary dye removal test at different pH, dosage, and temperature of functionalized CA/GO nanofiber demonstrates enhanced adsorption capacity of methylene blue in presence of p -SOCX compared to pristine CA nanofiber and CA/GO nanofiber at an optimum pH 8. The highest removal efficiency obtained was 88.84% with initial methylene blue dye concentration of 10 mg/L, adsorbent dosage of 20 mg/10 mL, contact time of 30 min at room temperature ca. 293 K. [ABSTRACT FROM AUTHOR]

The environmental pollution caused by organic dyes has damaged serious harm to human life. Hence, a series of Zr-Mg composite oxide nanoclusters with different metal ratios were synthesized by solvothermal method for adsorption of malachite green in aqueous solution. The optimal adsorbent with Zr/Mg metal molar ratio of 1 : 2 presented good adsorption performance, which adsorption capacity reached 12647.60 mg/g, and removal rate of malachite green reached more than 99%. These adsorbents were characterized by X-ray diffraction, Fourier-transform infrared spectra, nitrogen adsorption-desorption, scanning electron microscope, transmission electron microscope, and other methods. Influence of initial concentration of malachite green solution, pH, adsorption temperature, and contact time on absorption efficiency was investigated through batch experiments. Pseudo-second-order kinetic model can well describe the adsorption kinetic data. The three-parameter Sips isotherm model was more suitable for predicting the experimental results than Langmuir and Freundlich, and the adsorption process was endothermic. [ABSTRACT FROM AUTHOR]

Heat storage is a major problem in the world. Many research is going on the heat storage application. This research investigates the novel Ag/MgO/biochar nanocomposites for heat storage. Ag/MgO/biochar nanocomposites were fabricated using solvent-free ball milling techniques. According to several analytical measurements, the Ag/MgO nanoparticles in biochar are uniformly dispersed across the carbon interface. This type of adsorbent material has been characterized by different techniques such as X-ray diffraction pattern analysis (XRD), FTIR analysis, scanning electron microscope (SEM), and transmission electron microscope (TEM) as all indicate the surface morphology and successful ball milling synthesis of Ag/MgO nanocomposites. The UV visible spectroscopy wavelength range of AgNPs and MgONPs is 330 nm and 470 nm, respectively. FTIR analysis revealed that different functional groups of modified biochar nanocomposites such as O-H group are 3728 cm-1 and for C-H bond is 932 cm-1, C-O group is 1420 cm-1, and C=O is 1785 cm-1, respectively. Adsorption tests showed that 1.0 gL-1 dosage with 60% phosphate removal, an ion, and 0.2 gL-1 of dosages that had 85% methylene blue decomposition, a charged synthetic dye, were the lowest absorption levels. This research suggests that ball milling offers the advantages of stabilization and chemical adaptability for customized remediation of different atmospheric contaminants. Ball milling is a facile and feasible process to fabricate carbon-metal-oxide nanomaterials. [ABSTRACT FROM AUTHOR]

Green synthesis approach was successful used extract was successful in preparing bimetallic zero-valent Iron/Copper nanoparticles [FB-nZVFe/Cu]. Scanning Electron Microscope [SEM], Fourier Transform Infrared Spectroscopy [FTIR], and Dispersive X-ray Spectroscopy [EDX] showing the synthesizing of FB-nZVFe/Cu. The removal efficiency of Caffeine [5 mg L−1] reached 86% under the conditions [0.2 g L−1, 45 min, and pH 5]. The adsorption data are more appropriate by the Langmuir model [R2 = 0.9987] with qmax = 34.34 mg g −1. Kinetic results showed that Caffeine uptake is following pseudo-second-order. Langmuir and pseudo-second-order are more appropriate in linear and non-linear models. Overall, FB-Fe/Cu is a committed green substance for removal Caffeine from aqueous solutions. Functional parameters affect investigated using the Linear regression analysis, we found them to account for over 98% of the variables affecting the removal procedure. [ABSTRACT FROM AUTHOR]

In this study, activated carbons without any chemical residue were prepared from walnut shells. The preparation method in a tube furnace included a pyrolysis carbonization process and a CO2 activation process. The influences of activation temperature and holding time on the specific surface area, yield, and pore structure were investigated. Adsorption performance of water vapor was also examined in details. Thermogravimetric analysis, N2 adsorption–desorption isotherm, and scanning electron microscope were used to characterize samples. The result shows that the activation energy at different heating rates varies from 30.16 to 64.86 kJ/mol. The highest water vapor adsorption capacity of the sample is 0.3824 g/g and it takes only 30 min to realize regeneration. And the maximum Brunauer–Emmett–Teller specific surface area of 1228 m2/g also occurs in this optimal preparation condition. CO2 physical activation method was found to have a positive effect on pore structure development of activated carbon for water vapor adsorption. [ABSTRACT FROM AUTHOR]

The adsorption of Rhodamine B onto CT269DR resin has been studied through static and dynamic experiments. The effects of shaking speed, resin dosage, and pH on adsorption were investigated by static experiments. The external mass transfer rate remains substantially unchanged when the shaking speed exceeds 160 r min−1. The optimal pH range is 5–8, and an increase of resin dosage can directly improve the percentage of removal of Rhodamine B. The equilibrium isotherm data of Rhodamine B on CT269DR resin fit the Langmuir adsorption isotherm well. The thermodynamics parameters, Δ H = 69.93 kJ mol−1, Δ S = 326.73 J mol−1 K−1, and Δ G < 0, demonstrate that the adsorption of Rhodamine B onto CT269DR resin is spontaneous and endothermic. The pseudo first-order kinetic model can be successfully used to represent the adsorption process and the activation energy is 25.7 kJ mol−1. The dynamic experiments show that the breakthrough point is advanced when the flow rate increases and the bed adsorption capacity increases with increasing temperature. Furthermore, the desorption using the solution of 2% NaOH is suitable for desorption and reusing process, and scanning electron microscope (SEM) and fourier transform infrared spectroscopy (FT-IR) analysis reveals that used resin has good wear resistance and chemical stability. The results confirm that CT269DR resin can be employed as an efficient adsorbent for the removal of Rhodamine B from wastewater. [ABSTRACT FROM AUTHOR]

Nowadays, phenol and chlorophenols give rise to many organic pollutants. Concurrently, the occurring of phenolic compounds in aquatic ambit creates potential human health and environmental problems. There are a lot of technologies available for the treatment of organic pollutants. To remove phenol and chlorophenols, adsorption is a wastewater purification method. In this study, natural and activated clinoptilolite were carried out for the removal of phenol, ortho- chlorophenol, para -chlorophenol, and meta -chlorophenol. Activated clinoptilolite was prepared via acid activation and evaluated by means of Fourier transform infrared, scanning electron microscope, X-ray diffraction, X-ray fluorescence, and Brunauer–Emmett–Teller analysis. Phenol and chlorophenols have high adsorption rate, and equilibrium was reached in approximately 30 min. The maximum adsorptions of phenol, ortho- chlorophenol, meta -chlorophenol, and para -chlorophenols on the activated clinoptilolite were 6.7386, 8.6300, 9.5787, and 7.3758 mg g−1, respectively. The affinity order was in the following order: m -CP > o-CP > p-CP > Ph. The adsorption of phenol and chlorophenols decreased after pH = 6.25. Using the thermodynamic data, Gibbs free energy of the activated clinoptilolite was evaluated. The effects of different conditions such as pH, adsorption time, and initial concentration were analyzed. The adsorption rates of phenol and chlorophenols were constituted to be the maximum at approximately pH 6.5. Desorption of phenol and chlorophenols was carried out using ethyl alcohol solution (30%, v/v). The adsorption isotherms of phenol and chlorophenols on activated clinoptilolite were evaluated. The equilibrium adsorption data were the best suited to Freundlich adsorption isotherm pattern. [ABSTRACT FROM AUTHOR]

The surface heterogeneity of the multiwalled carbon nanotubes is investigated on the basis of adsorption isotherms from dilute aqueous phenol solutions at various temperatures. The Dubinin-Astakhov isotherm connected with the non-symmetrical distribution function of adsorption energies has been applied to describe adsorption equilibrium. Theoretical isosteric heats of adsorption connected with the Dubinin-Astakhov isotherm have been estimated as well. It is known that the decrease of the isosteric heat of adsorption with adsorbate loading is characteristic for the energetically heterogeneous surfaces. Theoretical description of kinetics is based on the Statistical Rate Theory of Interfacial Transport. The Statistical Rate Theory approach links the rate of transport between two phases with the difference in the chemical potentials of the molecules in these phases. Theoretical studies were verified successfully using the literature experimental adsorption data. [ABSTRACT FROM AUTHOR]

Activated carbon (AC) prepared from activation of ground peach stones with phosphoric acid under flowing air was used as a support for CeO2 and ZnO nanoparticles through hydrothermal method at 200°C for 120 min and followed by the calcination at 400°C for 180 min. The produced samples were named as AC, CeO2-AC, and ZnO-AC, respectively. The characterization of samples was made by means of scanning electron microscope, energy dispersive spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and Brunauer-Emmett-Teller surface area. A remarkable impact on the surface, structural, and textural properties of AC support was obtained as a result of loading for CeO2 or ZnO. Results of X-ray diffraction showed that nanocrystallines CeO2 and ZnO phases on the AC support were formed. Removal efficiency of the prepared samples was investigated through adsorption, photodegradation, and wet peroxide oxidation processes using Maxilon Red basic dye (MR). Accordingly, the prepared samples exhibited different removal behaviors towards MR dye depending on the total surface area and type of catalyst; for example, the maximum removal of MR dye was found in the following orders: AC>ZnO-AC>CeO2-AC, CeO2-AC>ZnO-AC>AC, and AC>CeO2- AC>ZnO-AC via adsorption, photodegradation, and catalytic oxidation with H2O2, respectively. It was found that photodegradation process was the best when compared with the other methods. The photocatalytic activity of CeO2-AC catalyst was the highest. The reusability tests showed that CeO2-AC exhibited superior photocatalytic performance and stability till the fourth run as compared to photocatalytic activity of ZnO-AC which decreased from 90% to 78% in the fourth run. Therefore, the prepared CeO2-AC catalyst is more effective than ZnO-AC as confirmed by reusability tests. [ABSTRACT FROM AUTHOR]

Cu(II) ion-imprinted polymer (IIP) was prepared by a surface molecular imprinting technique using Cu(II) as the template ion, aniline as the functional monomer, attapulgite (ATP) as the support and epichlorohydrin (ECH) as the cross-linking agent. In this study, the IIP was characterized using scanning electron microscope and Fourier transmission infrared spectrometry, and then the factors affecting adsorption were discussed. The selectivity and adsorption capacity for the Cu(II) ions on Cu(II) IIP were systematically studied. Under optimal conditions, the results of this study revealed that the IIP possesses a very strong adsorption and recognizing ability for the Cu(II) ions. The maximum adsorption capacity of IIP for Cu(II) was about 32.0 mg/g and its selectivity is twice that of a non-imprinted polymer. When the Cu(II)-polyaniline/ATP IIP was used repeatedly, its adsorption capacity remained constant. [ABSTRACT FROM AUTHOR]

The characterization and sorption properties of manganese oxide towards Cu(II) and Pb(II) ions from aqueous solution were investigated. Scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and infrared (IR) analyses were used to characterize the manganese oxide. Parameters affecting the adsorption of Cu(II) and Pb(II) ions, such as the adsorbent dosage, the ionic strength of the solution, the contact time, the solution pH, the initial metal ion concentration and the temperature, were investigated. The binding of Cu(II) and Pb(II) ions to manganese oxide was highly dependent on the pH of the solution, with the extent of adsorption increasing as the pH of the system increased. The uptake of both Cu(II) and Pb(II) ions was found to increase with temperature. Furthermore, the removal efficiency of Cu(II) and Pb(II) ions from aqueous solution increased with increasing adsorbent dosage and decreased with ionic strength. The adsorption equilibrium and adsorption kinetics of Cu(II) and Pb(II) ions onto manganese oxide were studied. The adsorption process was spontaneous and exothermic, with the order of affinity being Pb(II) > Cu(II). The same behaviour was observed during competitive adsorption, viz. adsorption from a binary solution of the ions concerned. [ABSTRACT FROM AUTHOR]