Pseudo 2nd Order Model Research Articles

Efficient separation of cerium from rare earth elements and major impurities using low cost manganese ferrites from highly acidic solutions

Sorption of REEs using spinel-ferrite nanoparticles has received great attention in the last decades, because of combining the advantages of iron and manganese metal oxides. Nano-manganese ferrite (MnFe2O4) was successfully synthesized using the co-precipitation method and modified with the addition of zinc to produce (Mn0.8Zn0.2Fe2O4). The synthesized materials were characterized using FTIR, SEM with EDX-mapping, XRD, chemical stability, and surface area. Several process parameters were studied to optimize the efficiency of Ce(III) separation from La(III), Eu(III), Pb(II), and Fe(III) from highly acidic media. The parameters include contact time, solution pH, and metal ion concentration. The sorption process was well fitted to the pseudo-2nd order model, which confirms the chemical nature of the sorption process where equilibrium was achieved after 30 minutes. The pH study's findings demonstrate that Ce(III) was most effectively separated at a very high, acidic pH of 0.5. Both MnFe2O4 and Mn0.8Zn0.2Fe2O4 have high chemical stability in different media where the weight loss was less than 10 %. The correlation coefficient and residual errors analysis confirm that the non-linear extended sips isotherm model more accurately expresses the behavior of the sorption process than the non-linear Freundlich and Langmuir isotherm models. The modified material Mn0.8 Zn0.2Fe2O4 shows higher sorption capacities for all the studied metal ions than MnFe2O4. The maximum sorption capacities of Ce(III), La(III), Eu(III), Pb(II), and Fe(III) in the mixture were 59.2, 6.5, 6.3, 15.4, and 13.7 mg/g, respectively.

Biosorption of Pb(II) Ions through Nanostructured Teff Straw based Magnetized Activated Biocarbon: Aspects on Modeling, Optimization, and Kinetics

<p>In this study, activated carbon (AC) was prepared from teff grass straw via chemical activation and microwave-assisted pyrolysis. The AC was modified by magnetization followed by it was characterized by particle size, FTIR, XRD, thermogravimetric study, pore size, and magnetic properties. Further, it was evaluated for its adsorptive removal performance of lead (II) ions from aqueous solution. A statistical model was developed by response surface method (RSM) and the crucial parameters, concentration of initial Pb(II), biosorbent loading, solution pH, and contact time were optimized for maximizing the adsorption of Pb(II) ions. The optimal values were 95.36 mg/L, 0.656 g/100 mL, 5.5, and 88.7 min, respectively for aforementioned parameters. Under the optimal condition, the Langmuir isotherm exhibited the most accurate correspondence with the obtained experimental data. The findings from the kinetic analysis were found to be statistically fit to the pseudo-2nd order model.</p>

Molecularly imprinted polymer for the selective removal of direct violet 51 from wastewater: synthesis, characterization, and environmental applications

Abstract Molecularly imprinted polymers (MIPs) are a diverse class of materials designed for selective molecular recognition. These polymers are synthesized with particular binding sites that are suited to a target molecule or a collection of structurally similar molecules through the use of a process called molecular imprinting. MIPs were synthesized in this work to specifically remove direct violet 51 from occupational leachates and aqueous solutions. Methacrylic acid functioned as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as the cross-linker, 2,2-azobisisobutyronitrile (AIBN) as the initiator, and alcohol as a porogenic solvent. To improve the dye removal effectiveness, a number of factors were optimized, including time, pH, analyte concentrations, and MIP/NIP dosages. The findings showed that MIPs had a much greater capacity for direct violet 51 adsorption than nonimprinted polymers (NIPs), with MIP adsorption capacity reaching 42.553 mg g−1 and NIP adsorption capacity reaching 7 mg g−1. The pseudo 2nd-order model described the adsorption kinetics, and the rate constant (K 2) for MIPs was found to be 0.00251 mg g−1 min. Furthermore, a high rebinding efficiency of 94 % was observed when the selectivity of MIPs for direct violet 51 was assessed against structurally similar templates.

Biosynthesis of calcium oxide nanoparticles by employing Mulberry (Morus nigra) leaf extract as an efficient source for Rhodamine B remediation

Green processes for synthesizing nanocomposites are a hot area of research today as traditional processes are expensive, inefficient, harmful for synthesizing organic and inorganic molecules, and unsuitable for large-scale operations. The present study investigates the capacity of green synthesized Calcium oxide nanoparticles (CaO NPs) for efficiently removing Rhodamine B. Chemical reduction was replaced with Mulberry (Morus nigera) leaf extract as an environmentally friendly reaction mechanism. CaO NPs are characterized by various analytical techniques including EDX, BET, SEM, FTIR, TGA, Zeta Potential, Point of Zero Charge (PZC), and XRD. Maximum adsorption of Rhodamine B by CaO NPs is revealed at an initial concentration of Rhodamine B of 80 ppm, a temperature of 343 K, and contact time of 60 min, 0.4 g of adsorbent at a pH value of 7. Maximum removal of Rhodamine B by CaO NPs was found to be 98.2% which is promising with this small amount of adsorbent (0.4 g). Diverse Kinetic and adsorption isotherms are employed in this study to determine the requirement and significance of the adsorption process. Various adsorption isotherms such as Freundlich, Temkin, Dubinin–Radushkevich (D–R), and Langmuir models have been employed. Among the kinetic adsorption isotherms Elovich, Intraparticle kinetic model, pseudo 1st order, and pseudo 2nd order models were applied. The current study investigates the thorough understanding of the Rhodamine B adsorption process including the mechanism of adsorption using condition optimization, characterization, and model applications. The proposed adsorbent can be employed for the green removal of Rhodamine B from wastewater of industry with maximum efficiency and favorable regeneration properties.

Synergistic degradation of toxic azo dyes using Mn-CuO@Biochar: An efficient adsorptive and photocatalytic approach for wastewater treatment

Congo red (CR) and Eriochrome Black T (EBT) is a toxic azo dye with a complex structure which represents a serious Ecotoxicological hazards for aquatic bodies. This research investigates the synergistic effects of Corn plants biochar and manganese (Mn)-composited copper oxide (CuO) in the adsorptive and photocatalytic degradation of toxic anionic dyes i.e. CR and EBT. The acquired materials were characterized by FTIR, XRD, SEM-EDX, XPS, TEM, BET, ZP, and pHZc test. The experiment demonstrated that Mn-CuO@BC composite exhibited a remarkable adsorption of ∼ 98 % and ∼ 95 % and photocatalytic degradation of 92 % and 88 % for CR and EBT respectively. It was further found that coupling of the H2O2 with Mn-CuO@BC enhances the photocatalytic efficiency of catalyst for CR and EBT i.e. upto ∼ 98 % and 96 % respectively possibly owing to the efficient ●OH radical. Adsorption kinetics followed a pseudo 2nd order model, indicating predominant chemisorption, and adsorption isotherms fit well with the Langmuir model. Further, toxicity degradation products of EBT were examined through ECOSAR indicated a reduced ecological impact. In general, this work highlight the dual functional advantages of the Mn-CuO@BC composite, providing an efficient and versatile approach for wastewater treatment involving complex dye pollutants.

Addressing small-scale temperature swing adsorption challenges using intensified fluidised bed technology for carbon capture process development

Polyethylenimine (PEI)-based adsorbents exhibit high CO2 capacities, making them potential candidates for mitigating unavoidable industrial CO2 emissions. However, desorption of CO2 from PEI, and from adsorbents in general, has received far less attention in the literature than adsorption. Whilst Temperature Swing Adsorption (TSA) is simple to conceptualise, it is difficult to implement in small-scale experiments in practice. Here we study the desorption characteristics of a commercial branched PEI adsorbent in a small-scale swirling fluidised bed reactor (TORBED) to improve the small-scale heat transfer rates. Our experimental results show that higher desorption temperatures, higher gas flow rates, and higher CO2 concentrations during adsorption can improve the desorption efficiency (defined as the amount of CO2 removed as a fraction of the initial amount adsorbed). In terms of kinetics, we found that the fractional order kinetic model provided the best fit to the PEI adsorbent, implying that this adsorbent involves multiple simultaneous molecular interactions, physisorption processes, and chemisorption processes, that cannot be described by simpler pseudo 1st or 2nd order models. Desorption rates in the TORBED in this study were 1 order of magnitude faster than fluidised beds, and 2–3 orders of magnitude faster than packed beds.

A new insight into the mechanism of MNB-assisted flotation of copper: A link between chalcopyrite and its-bearing bulk ore

The present study systematically explores the relationship between chalcopyrite mono-mineral and copper-bearing ore flotation in the presence and absence of micro- and nano-bubbles (MNBs). Ultrafine bubbles were generated through a cavitation mechanism, and their stability, size, and zeta potential were monitored over a period of 0–25 days. Micro-flotation and batch rougher kinetic flotation experiments were carried out with and without ultrafine bubbles using a modified Hallimond tube and 2.5 L Denver® flotation cell, respectively. The results showed that the presence of MNBs improved the recovery of chalcopyrite mono-mineral and its ore by 24.5 % and 7 %, respectively. Furthermore, the adsorption behavior of sodium isopropyl xanthate (SIPX) collector at various concentrations was analyzed in the presence and absence of stable MNBs using UV–visible spectroscopy, FTIR analysis and kinetic models. The adsorption studies supported the micro-flotation findings, demonstrating that the presence of MNBs not only boosted collector adsorption on the chalcopyrite surface (by an average of 73.8 %) but also improved the adsorption kinetics (by 69.44 %). The sorption kinetics followed the pseudo 2nd order model in the presence of MNBs, while in the absence of MNBs, both pseudo 1st order and pseudo 2nd order models were observed. The sorption of SIPX onto chalcopyrite was identified as a chemisorption process in the presence of MNBs, whereas it was a physicochemical sorption in the absence of MNBs.

PREPARATION AND CHARACTERIZATION OF NEW IMINE- FUNCTIONAL GROUP FOR FAST REMOVAL OF Cr (III) IN SOME SUPPLEMENTS FROM SHRIMP SHELL

A new imine-Schiff base adsorbent is prepared from extracted chitosan to make taking away exoskeletons of crustacean shrimp shells low-cost and environmentally friendly with the fast and high ability to remove Cr (III) from aqueous solution. The resulting composites were verified by different techniques FTIR, H-NMR, FESEM, EDX, XRD. On applying the adsorption kinetic model, the pseudo 2nd order model was best characterised, using adsorption equilibrium data; the Langmuir model provided a superior description. Further, the negative value of ∆G shows a spontaneous process in nature. Finally, the prepared adsorbent has been applied to a real sample of bodybuilder supplements.

Carbohydrate polymers based MnO2 nanostructures for catalytic and antibacterial activity; kinetic modeling and molecular docking analysis

In this project, cellulose nanocrystal-CNC, chitosan-CS, and starch-St doped MnO2 nanostructures (NSs) were synthesized by a co-precipitation approach. The motive of this research was to evaluate the effect of CNC, CS, and St on catalytic activity, kinetic adsorption, and antimicrobial potency with molecular docking (MD) analysis of MnO2. The hydrophilic head of polymers interacts with MnO2 NSs to regulate the growth, recombination rate, and stability of nanostructures. Notably, St-doped MnO2 exhibited the highest catalytic potency in an acidic medium in comparison to basic and neutral media. The kinetic modeling (pseudo-1st, pseudo-2nd order, Elovich, and intra-particle diffusion model) suggests that the adsorption of RhB dye by the NSs follows the pseudo-second-order kinetics. Among all samples, CNC-MnO2 and St-MnO2 proved to be an efficient antibacterial agents against E. coli and s. aureus bacteria, respectively. Findings revealed that polymer-based MnO2 nanostructures were the most efficient inhibitors of DNA gyrase against E. coli and S. aureus.

Zinc oxide nanoparticles encapsulated in alginate beads: a promising and recyclable adsorbent for simultaneous uptake of toxic metals

Heavy metal toxicity is a known problem and various methods are used for treatment. Adsorption has some advantages and it would be promising if environmentally friendly and cheap materials were utilized. Alginate and zinc oxide nanoparticles were selected and composite alginate beads were used for the removal of mixed metals from aqueous solutions. Batch and column experiments were conducted to determine some parameters’ effects and the adsorbent’s real application potential. According to the batch experiments, zinc oxide nanoparticles to alginate ratio of 0.5 g g−1, and pH levels nearby to the neutral range led to better metal removals. 0.5 ml min−1 of flow rate supplied better metal removal efficiencies in columns, with the highest treatment as 86% of Pb2+. Acid treatment can be successfully applied for the regeneration of the adsorbent, at least three times only with a 4% reduction in the adsorption efficiency. Heavy metal uptake was compatible with the pseudo 2nd order model indicating chemisorption as a dominant mechanism. Also, the intraparticle diffusion model illustrated adsorption might govern more than one step. The Langmuir model had the best fit and suggested monolayer covering for Pb2+, 76.3 mg g−1. Alginate-based nanocomposite beads were useful for mixed metal removal and could be used.

On-Line pH Measurement Cation Exchange Kinetics of Y3+-Exchanged Alginic Acid for Y2O3 Nanoparticles Synthesis.

A new sol-gel method that employs cation exchange from an aqueous metal ion solution with H+ ions of granulated alginic acid was developed for synthesizing high-purity Y2O3 nanoparticles. In this study, the cation exchange kinetics of H+~Y3+ in aqueous solution were analyzed using on-line pH technology and off-line inductively coupled plasma-atomic emission spectrometry (ICP-AES) analysis. Pseudo 2nd-order models were utilized to evaluate the parameters of the kinetics, suggesting that the concentration of H+~Y3+ involved in the cation exchange reaction was 1:1.733. Further, a comprehensive understanding of the Y-ALG calcination process was developed using thermo-gravimetric analysis, along with results obtained from differential scanning calorimetry (TGA/DSC). A detailed analysis of the XRD Rietveld refinement plots revealed that the crystallite sizes of Y2O3 nanoparticles were about 4 nm (500 °C) and 15 nm (800 °C), respectively. Differential pulse voltammetry (DPV) was employed to investigate the electrochemical oxidation of catechol. The oxidation peak currents of catechol at Y2O3 (500 °C)/GCE and Y2O3 (800 °C)/GCE showed two stages linear function of concentration (2.0~20.0 × 10-6 mol/L, 20.0~60.0 × 10-6 mol/L). The results indicated that the detection limits were equal to 2.4 × 10-7 mol/L (Y2O3 (500 °C)/GCE) and 7.8 × 10-7 mol/L (Y2O3 (800 °C)/GCE). The study not only provided a method to synthesize metal oxide, but also proposed a promising on-line pH model to study cation exchange kinetics.

Removal of chromium(III) from contaminated waters using cobalt ferrite: how safe is remediated water to aquatic wildlife?

The release of hazardous elements by industrial effluents to aquatic ecosystems is a potential threat to the environment. Chromium (Cr) is one of the elements whose levels in several freshwater ecosystems should be reduced to promote water reuse. In recent years, magnetic materials have gained increasing interest as sorbents because of their easy removal from treated water through magnetic separation. In this study, colloidal cobalt ferrite (CoFe2O4) particles were investigated as magnetic sorbents for chromium-aqueous chemical species. The oxidative stress responses of Mytilus galloprovincialis mussels exposed to 200 μg/L of Cr, resembling remediated water, were evaluated. More than 95% of Cr was removed from contaminated solutions by CoFe2O4 aqueous suspensions at pH 6 and pH 10. The kinetics of sorption experiments were examined using pseudo-1st order, pseudo-2nd order and Elovich models to evaluate which mathematical model has a better adjustment to the experimental data. The present study revealed that the levels of Cr that remained in remediated water induced limited biochemical changes in mussels, being considered safe for aquatic systems. Overall, the use of cobalt ferrite–based sorbents may constitute a promising approach to remediate contaminated water.

Adsorption of crystal violet using a composite based on graphene Oxide-ED@Cellulose: Adsorption modeling, optimization and recycling

The current work, provides the results of a study related to the synthesis of composite based on ethylene diamine modified reduced graphene oxide and cellulose (rGO-ED@Cellulose) to improve the dispersion of GO sheets. After improving its properties, the composite was employed for the adsorption of crystal violet, a cationic dye. Point zero charge (pHPZC) was used to characterize the composite, in addition to other methods including X-ray diffraction, scanning electron microscopy, and energy dispersion X-ray spectroscopy (FTIR, XRD, and SEM/EDS). Studies on batch adsorption were conducted with operational parameters such as contact time, dosage of the adsorbent, concentration of the dye, pH, and temperature. The optimal parameters found were t = 80 min, 10 ppm, pH = 6, m = 0.1 g and T = 25 °C, this resulted in a capacity of adsorption of crystal violet value of 260 mg. g−1 and an adsorption efficiency of 88 %. The kinetic study showed that the adsorption of the cationic CV dye on the composite follows a pseudo 2nd order model kinetic. The Langmuir model was found to be a good fit for the isothermal data of the crystal violet adsorption by the composite study and the adsorption process is exothermic. A statistical model was used to assess the efficacy of CV adsorption on rGO-ED@Cellulose composite surface locations. The evaluation was carried out in a practical setting, utilizing a three-level Response Surface Methodology (RSM) based on Box-Behnken Design and the Expert Design software package.

Effective removal of heavy metals from aqueous solution using CS/OMMT nanocomposite synthesized by gamma irradiation

The current investigation involved the fabrication of nanocomposites CS/OMMT through polymerization initiated by γ-rays irradiation. The product was characterized using FTIR and SEM techniques. The current analysis aimed to determine the adsorption performance of lead (II) ions onto nanocomposites that were synthesized, using a batch adsorption technique in an aqueous medium. The investigation analyzed the influence of different issues on the adsorption capability of the nanocomposite. Further, the lead (II) concentration, medium pH, contact time & adsorbent use were taken into account. Adsorption process order was determined with the help of kinetics. Kinetics data of pseudo 1st and 2nd order models were analyzed. There was a strong correlation between the data and the second-order kinetic model. Based on our research, we conclude that the nanocomposite showed good agreement with the Langmuir model of Pb(II) ions. The nanocomposite underwent a desorption procedure utilizing solutions of CaCl2, NaCl and 0.01 M HNO3 to attain complete elimination of Pb(II) ions. This process are revealed that CS/OMMT demonstrated remarkable efficacy as an absorbent for heavy metal ions, suggesting its potential as a viable method for purifying heavy metal-contaminated water.

Sequestration of chromium(vi) and nickel(ii) heavy metals from unhygienic water via sustainable and innovative magnetic nanotechnology.

In a stride towards sustainable solutions, this research endeavors to address the critical issue of water pollution via heavy metals by coupling the power of magnetic nanotechnology, in combination with a green chemistry approach, to eliminate two noxious inorganic pollutants: chromium(vi) and nickel(ii) from aqueous environments. The synthesis of magnetite (Fe3O4) nanoparticles was achieved using ferric chloride hexahydrate (FeCl3·6H2O) as a precursor, with the assistance of Ziziphus mauritiana Lam. leaves extract, known for its remarkable salt-reducing properties. A range of bio-adsorbents, derived from corncob biomass, corncob pyrolyzed biochar, and magnetite/corncob biochar nanocomposite (NC), were engineered for their eco-friendly and biocompatible characteristics. Extensive parametric optimizations, including variations in pH, contact time, dose rate, and concentration, were carried out to gain insights into the adsorption behavior and capacity of these bioadsorbents concerning Cr(vi) and Ni(ii). Equilibrium and kinetic studies were undertaken to comprehensively understand the adsorption dynamics. In the case of Ni(ii), the Freundlich isotherm model provided a satisfactory fit for all bio-adsorbents, demonstrating R2 values of 0.91, 0.95, and 0.96 for BM, BC, and NC, respectively. Furthermore, the pseudo 1st order model emerged as the most suitable fit for Cr(vi) sequestration in corncob BM with an R2 value of 0.98, while pseudo 2nd order models were robustly fitted for BC and NC, yielding R2 values of 0.88 and 0.99, respectively. The magnetite/corncob nanocomposite outperformed other bioadsorbents in removing heavy metals from wastewater due to its environmental friendliness, larger surface area, reusability, and cost-effectiveness at an industrial scale.

Pyrolyzed bone char for nitrobenzene adsorption: Insight into the physicochemical characterizations and adsorption mechanisms

In this study, the preparation of pyrolyzed bone chars for the removal of nitrobenzene (NB) from the water was examined. Adsorption properties of bone chars prepared at diverse pyrolysis temperatures (300–900 ℃) were investigated for removing NB from aqueous solutions. At higher temperatures (700 and 900 ℃), bone chars showed superior adsorption properties for NB removal, and physicochemical characterizations showed that the pyrolyzed bone chars possessed improved properties and amended porous structure after pyrolysis treatment. Pyrolysis temperatures of > 700 ℃ contributed to the dehydroxylation of hydroxyapatite of bone chars, increasing their NB adsorption performance. Maximum NB adsorption capacity of higher temperature pyrolyzed bone chars calculated from the Langmuir isotherm model was 142.41 and 204.34 mg/g for bone char-700 and bone char-900, respectively, indicating that the bone chars had the potential for enhanced NB adsorption. For adsorption isotherm parameters, two-parameter (Langmuir and Freundlich) models showed satisfactory results of NB adsorption on bone char from aqueous solution. Adsorption kinetic parameters of NB adsorption on bone chars showed pleasing results for the pseudo 2nd order model. This study shows that the pyrolyzed bone char is an efficient adsorbent for removing NB from water.

Copper (II) ions extraction by poly(N-vinylcaprolactam-mathacrylic acid) microgels for in situ reduction formation of copper nanoparticles to reduce pollutants

It is very important to eliminate organic dyes and most of the toxic transition metal ions from water because they are hazardous substances for livings. Many systems are reported to eliminate organic pollutants or transition metal ions solely from water. A new systematic way has been developed for effectively removal of both metal ions and organic pollutants (nitroarenes and toxic dyes). For this purpose, a spherical poly(N-vinylcaprolactam-co-methacrylic acid) P(NVC-MAAc) microgel system was developed by free radical precipitation polymerization (FRPP) method. The XRD, FTIR, SEM, DLS, and TEM techniques were used for characterization of P(NVC-MAAc) system and then used that system as an adsorbent for removal of copper (II) ions from water under a variety of conditions, including different P(NVC-MAAc) concentrations, pH, copper (II) ions contents, and agitation times. Various adsorption isotherms were applied to evaluate the best fitted adsorption isotherms for extraction of copper (II) ions with P(NVC-MAAc) microgel system. Furthermore, the kinetics of copper (II) ion adsorption on P(NVC-MAAc) were investigated using the pseudo-1st order (P1O), intra-particle diffusion model (InPDM), pseudo-2nd order (P2O), and Elovich model (EM). The loaded copper (II) ions in P(NVC-MAAc) microgel were then in-situ reduced to generate copper nanoparticles (NPs). The resulted [Cu-P(NVC-AAc)] hybrid microgels were used as catalyst to reduce toxic pollutants from water such as 4-nitrophenol (4NiP), 4-nitroaniline (4NiA), chromium (VI) ions (ChVI), rhodamine-B (RhB), methyl orange (MeO), and eyosin-Y (EyY). The values of apparent rate constant (kapp) for 4NiP, 4NiA, ChVI, RhB, MeO and EyY were found 0.725 min−1, 0.587 min−1, 0.097 min−1, 0.821 min−1, 0.860 min−1, and 0.833 min−1 respectively. As a result, a broad range of new organic transformations can be efficiently catalyzed by the Cu-P(NVC-MAAc) system.

Synthesis of magnetic biochar derived from waste wood of acacia Auriculiformis for the removal of arsenic

The current study has established a new method to prepare magnetic biochar from waste wood derived from the Acacia Auriculiformis. Slow pyrolysis method was deployed for the conversion of waste wood into biochar. Iron powder was transformed into iron-oxide nanoparticles which were then deposited onto the biochar's surface. The prepared adsorbent contains a high specific surface area of 266.564 m2g−1. SEM images demonstrate the formation of triangular pyramid-shaped nanoparticles in the adsorbent's inner-wall pores. According to XRD peaks, the adsorbent's surface was coated with crystalline, carbonaceous, and Fe3O4. FTIR analysis indicates that multiple aliphatic and aromatic stretching bonds of carbon and hydroxyl bond act as functional groups in the impregnation and arsenic adsorption process. Establishment of best fit model which is Freundlich indicated towards the multi-layer heterogeneous adsorption process. 95 % removal efficiency is achieved with batch study whereas kinetic pseudo 2nd order model represents the adsorption process. Surface mechanism involved electrostatic attraction followed by Bangham equation and Weber Morris intra-particle diffusion and complexation helping in adsorption of the arsenic ions. The maximum capacity of the manufactured biochar is estimated to be 294.1176 mgg−1.

Towards sustainable water purification: MOFs as a promising solution to eliminate toxic water pollutant resorcinol

Abstract Water pollutants especially alcoholic based aromatic compounds are documented as emergent water pollutants and caused serious health problems for all living organisms. It is a major challenge for all researchers to synthesize effective adsorbents to eliminate these water pollutants. For this purpose, two MOFs were synthesized and characterized using SEM, FTIR, EDX and PXRD techniques. These MOFs exhibited excellent adsorption capacity for resorcinol and adsorption process was spontaneous, endothermic and proceeds with physiosorption as confirmed using thermodynamics data (∆H ads = 30.473 kJ/mol). Furthermore, separation-factor value was in the range of 0.0238–0.1312 for 30–100 ppm resorcinol concentration which represents that adsorption process was favorable. Langmuir and Pseudo 2nd order Models were best described which represented that chemisorption process also favored due to presence of –OH group and N-atom between adsorbent and adsorbate as well as monolayer adsorption-process is proceeded. Moreover, ion-exchange and electrostatic-interactions are the major interactions which are responsible for adsorption of resorcinol. Along with electrostatic-interactions, ion-exchange, hydrogen-bonding and π–π stacking/interactions are also accountable for adsorptive elimination of resorcinol. In summary we can conclude that MOFs are considered outstanding adsorbents for elimination of water pollutants to purify water, as water is very important for healthy life.

Rietveld refinement, Morphological, Optical and Photocatalytic Dye Degradation Studies of Pristine and Sr-Doped SnS2 Hexagonal Nanoplates

In the present study, SrxSn1-xS2 hexagonal nanoplates have been synthesized via a cost-effective hydrothermal route and characterized by XRD, UV-DRS, PL, SEM, EDXS, Zeta potential, and dye degradation. The XRD pattern confirms the structure and FESEM corroborates the hexagonal nanoplate morphology of all the synthesized samples while EDX ascertains the Sr presence in doped samples. The optical band gap energy (Eg) of the samples has been estimated using UV-DRS and is found in the visible region. The negative surface charge is ascertained using the Zeta potential (ζ) analyzer. The dye degradation efficiency of pristine and SrxSn1-xS2 is tested on RhB under a visible lamp of 250W for 120min and found highest for x = 0.06 sample (90.93 %). The adsorption kinetics follows the pseudo 2nd order model whereas photodegradation kinetics follows 1st order kinetics model. Further isotherms processes studied in the dark follow the Langmuir model.