Initial Solution Concentration Research Articles

Tecoma stans intermediated green synthesis of copper oxide nanoparticles, its characterization, paracetamol degradation and biological activities

The main objective of the present research work is to green synthesize copper oxide nanoparticles (CuO NPs) and to study its potential against various enmities to safeguard our environment and health. Based on this approach, preparation of CuO NPs was accomplished using four different volumes (10, 25, 40, and 50 mL of leaves extract) of Tecoma stansleaves extract. Moreover, all the synthesized CuO NPs were characterized using XRD, UV–visible, FTIR, and SEM with EDS analysis. From the XRD pattern, the structures of all the synthesized CuO NPs were found to be monoclinic in phase. According to the UV–visible studies, the calculated band gap energy values for all the prepared CuO NPs were higher compared to bulk CuO, which was 1.2 eV. Further, the FTIR results showed the presence of CuO bond and SEM with EDS analysis revealed the surface morphology of CuO NPs andthe presence of elements showing the purity of synthesized CuO NPs, respectively. The optimized condition for the preparation of CuO NPs were 50 mL of leaves extract mixed with 50 mL of double distilled water (CuO4 NPs) showed a spheroidal morphology as evident from the HRTEM images. XPS analysis used to find the oxidation state of detected elements especially for copper and oxygen. The predicted BET and Langmuir surface area of CuO4 NPs were calculated to be 40.305 m2/g and 5074.12 m2/g respectively. Photocatalytic degradation of paracetamol (PCM) using CuO4 NPs was investigated, and the effect of parameters such as pH, initial concentration of PCM solution, and catalyst dosage were studied under UV light irradiation. The highest removal of 95.15 % had been achieved at 120 min under optimized reaction conditions. Additionally, CuO4 NPs also exhibited exemplary antibacterial activity against bacillus subtilis bacteria with a zone of inhibition of 26 mm. Further, in vitro cytotoxic behaviour of CuO4 NPs was estimated using A549 cancer cells by MTT assay. Thus, the green synthesis of CuO NPs using Tecoma stans leaves extract has the capacity to participate in photocatalytic and biological activities.

Improving both energetic and kinetic performances of osmotic battery for grid energy storage

Osmotic battery (OB), alternating the operation of reverse osmosis (RO) for charging and pressure-retarded osmosis (PRO) for discharging, is an emerging grid-scale energy storage system (ESS) that offers complementary advantages over other existing grid ESSs. OB utilizes osmotic pressure difference of two solutions as a media for energy storage. However, OB faces the issue of energetic-kinetic trade-off generally applicable in all the ESSs. This study aims to quantitatively analyze this trade-off in OB and to develop effective strategies to address this issue. Our analyses suggest that this trade-off can be addressed by (1) raising the initial high-salinity solution concentration (cHS,0), and (2) using more water permeable osmotic membranes with a suitable high-salinity solution. For example, increasing the cHS,0 from 1.2 M to 2.4 M increases energy density from 0.5 to >1.0 kWh·m−3 along with an enhanced power density and a stable high roundtrip efficiency (RTE) above 66 %, albeit requiring membranes with substantially improved mechanical strength. Furthermore, using high-permeance nanofiltration-type osmotic membranes with divalent high-salinity solution could improve the peak power density to above 50 W·m−2 while maintaining energetic performance. This study not only offers effective strategies to ease the energetic-kinetic trade-off but also recommends important directions for developing future osmotic membranes for OB.

Modified Fly Ash as an Adsorbent for the Removal of Pharmaceutical Residues from Water

In this work, different methods for fly ash modification were applied to obtain an adsorbent for the efficient removal of selected pharmaceuticals from a multiclass aqueous solution. Morphological and surface properties of the modified fly ash samples were analyzed by scanning electron microscopy, X-ray fluorescence, X-ray diffraction, Fourier transform infrared spectroscopy, and point of zero charge, and the influence of the applied modifications was determined by comparison with the results obtained for unmodified fly ash. Experimental parameters of the adsorption of the pharmaceutical onto the modified fly ash were optimized, and special attention was paid to the influence of different parameters on the adsorption capacities. Multivariate methods of analysis, such as artificial neural networks, applied to the obtained results showed that the contact time, the initial concentration of the pharmaceutical solution, and the pH value had the strongest influence on the adsorption process. Fly ash modified with chitosan and magnetic iron oxide showed the best adsorption properties (removal efficiency above 80% for the majority of the selected pharmaceuticals), and artificial neural networks confirmed its susceptibility to the modeling process.

Ibuprofen photodegradation promoted by ZnO and TiO2-P25 nanoparticles: A comprehensive kinetic, reaction mechanisms, and thermodynamic investigation

Photocatalytic activity, reaction kinetics, modeling, and thermodynamics of commercial TiO2-P25 and ZnO nanoparticles (NPs) for ibuprofen (IBU) photodegradation were investigated. Photodegradation experiments were performed in a batch reactor under UV irradiation. The photodegradation performances of TiO2-P25 and ZnO NPs were further studied and modeled under different operation conditions, by varying the reaction temperature, catalyst bulk density, and the initial concentration of the IBU solution. The descriptive kinetic models for the experimental data were tested, through the estimated kinetic parameters, together with the statistical information, revealing that the reaction rate in the case of TiO2-P25 is of first order while the ZnO NPs follow second-order kinetics with respect to IBU. The photodegradation mechanisms for both TiO2-P25 and ZnO NPs were determined to be Langmuir-Hinshelwood and Eley-Rideal, respectively. Thermodynamic parameters were assessed, particularly, changes in Gibbs free energy, enthalpy, and entropy indicating the efficient photodegradation performance of these NPs.

Removal of methylene blue from dye wastewater by cattail leaf-based porous carbon materials

ABSTRACT In this work, cattail leaf-based porous carbon materials (KCL-800-2 and PCL-500-2) with high specific surface were prepared from cattail leaf powder. The structure and morphology of cattail leaf-based porous carbon materials were characterized using SEM and BET. The results showed that the cattail leaf-based porous carbon materials have well-developed pore structure. The highest adsorption capacity of KCL (199.995 mg·g−1) was obtained with an alkaline-carbon ratio of 4:1, an activation temperature of 800°C and an activation time of 2 h. The highest adsorption capacity of PCL (92.0675 mg·g−1) was obtained with a phosphoric acid-carbon ratio of 2:1, an activation temperature of 500°C and an activation time of 2 h. The conditions for the adsorption of methylene blue on the KCL-800-2 and PCL-500-2 were investigated by a one-factor test. The optimization of the adsorption of methylene blue by KCL-800-2 and PCL-500-2 was carried out by a one-way test, and the results showed that the optimal adsorption conditions were temperature 298.15 K, PH 7, adsorption time 12 h, adsorbent dosage of 15, 20 mg, and the initial concentration of MB solution of 100 mg·L−1, 50 mg·L−1, and the adsorption capacity of the adsorbent under the conditions reached 127.3337 mg·g−1, 44.9886 mg·g−1 and 44.9886 mg·g−1, respectively. 44.9886 mg·g−1, respectively. The adsorption data of KCL-800-2 and PCL-500-2 on methylene blue (MB) fitted well with the Langmuir isothermal model and pseudo-second-order model. The adsorption process was a spontaneous, heat-absorbing entropy, monomolecular layer adsorption process.

Novel Poly(N‐(1‐cyclohexylethyl)Acrylamide‐co‐Styrene‐co‐Ethyleneglycol Dimethacrylate) Synthesis for Efficient Methylene Blue Adsorption from Aqueous Solutions Synthesis

AbstractSynthesis and evaluation of a new polymeric adsorbent for adsorbing methylene blue (MB) from these economical aqueous solutions were investigated. In the first step of the study, N‐(1‐cyclohexylethyl)acrylamide (CEA) monomer was synthesized using S‐(+)‐1‐cyclohexylethylamine and acryloyl and the obtained CEA was analyzed by FTIR, 1H‐NMR, and 13C‐NMR. Then, a poly(CEA‐co‐Styrene‐co‐EGDMA) copolymer was obtained by cross‐linking CEA monomer, ethylene glycol dimethacrylate (EGDMA) and styrene monomers by subsequent radical polymerization episodes. FTIR, solid‐NMR, and elemental analysis methods were used for the characterization of this copolymer. In the last step of the study, the obtained poly(CEA‐co‐Styrene‐co‐EGDMA) copolymer was used as an adsorbent to adsorb MB from aqueous solutions. In the study, various factors such as adsorption properties, adsorbent dose, contact time, initial concentration, and solution pH were investigated. In the study, the most suitable adsorbent dose was determined as 0.1 g, initial solution concentration as 500 mg/L, contact time as 70 min, and pH as 7. Adsorption capacity was determined as 256.4 mg/g at 25 °C. As a result of the analysis of kinetic data, it was found that the model with the highest regression coefficient and the best fit with the experimental data was the pseudo‐second‐order kinetic model.

Elimination of torasemide from aqueous medium: influence of sorption and photocatalytic processes parameters supported by DFT analysis.

The sorption and photocatalytic activity of pharmaceutical torasemide using an immobilized TiO2 photocatalyst were investigate. The experimental design included optimization of reaction conditions such as pH and initial pharmaceutical concentration in aqueous solution using the response surface modeling approach, scavenger tests to gain insight into the photocatalysis mechanism, and application of the process to more complex water matrices. TiO2 in the role of sorbent showed a low capacity for torasemide (12.23-29.83μg/g within 24h of contact), making this type of removal inefficient on its own. Investigating the sorption process influenced by different process parameters such as pH, temperature, ionic strength, and dosage of TiO2 applied, the low tendency to this kind of material was affirmed by low Kd values (0.70 to 6.78mL/g) obtained by linear isotherms. Photocatalysis proved to be the better choice for the removal of torasemide from water, with the best kinetics at pH 4 and concentration of 5mg/L with half-time for degradation of 34.83min. Computational DFT analysis identified the zwitterionic torasemide structure as predominant under neutral and acidic conditions. It also showed that negatively charged areas around nitrogen-containing fragments probably have the highest potential to promote the TiO2 sorption at low pH conditions, where it is highest, through electrostatic attractions and N-H∙∙∙∙∙OTiO2 hydrogen-bonding contacts.

Exploring non-thermal plasma technology for microalgae removal

The global population and economic development surge has substantially increased water demand, resulting in heightened sewage and pollutant generation, posing environmental hazards. Addressing this challenge necessitates the implementation of efficient and cost-effective water reclamation methods. Non-thermal plasma technology (NTP) has emerged as a promising solution, garnering attention for its superior efficiency compared to alternatives. While existing studies have predominantly focused on energy efficiency and pollutant removal, limited research has delved into the biological removal aspect, particularly concerning algae. This study utilized a dielectric barrier plasma diffuser to eliminate Spirulina microalgae (Spirulina platensis) from wastewater solutions, demonstrating higher algae removal and superior mass transfer compared to alternative plasma methods. The effect of sample volume, input voltage and power, flow rate, and initial solution concentration on the algae removal was investigated. Investigation of operational parameters revealed the best condition resulting in a 98 % removal rate and 20 g/kWh energy efficiency. The best conditions for the removal of Spirulina microalgae were considered in a sample volume of 50 mL, a voltage of 7.6 kV, a flow rate of 700 mL/min, and an initial solution concentration of 1280 mg/liter. Scanning Electron Microscope (SEM) images illustrated the impact of active species on cell structure, leading to the destruction of spiral form and loss of reproductive ability. The study underscores the potential of NTP for efficient algae removal and identifies key active species involved in the process. The removal of Spirulina microalgae was attributed to a combination of singlet oxygen (1O2), hydroxyl radicals, and ozone.

ДОСЛІДЖЕННЯ АДСОРБЦІЇ CrО42- ТА Cr2О72- ПОЛІАНІЛІНОМ ІЗ ВОДНИХ РОЗЧИНІВ

The optical properties of aqueous solutions of chromate CrО42- and dichromate Cr2О72- ions were studied. Optical spectra were used to study the adsorption of chromate CrО42- and dichromate Cr2О72- ions by a sample of polyaniline (PAn) from aqueous solutions of different concentrations. It was established that the removal and adsorption of CrО42- and Cr2О72- by the PAn sample depends on the concentration of oxyanions in the initial solutions. Adsorption studies of PAn sample with respect to oxyanions CrО42- and Cr2О72- were carried out from solutions with concentrations of 50, 100, 150, 200 and 250 mg/L. Examination of the samples after the adsorption tests revealed that the polyaniline sample retains adsorbed chromium, apparently in the Cr(III) state. The analysis of SEM-images, EDX-spectra and maps of elements proves that the distribution of adsorbed chromium is practically uniform over the surface of the adsorbent, and the intensity of its signal on the elemental maps depends on the initial concentrations of solutions of oxyanions CrО42- and Cr2О72-. Examination of the PAn sample using SEM-EDX spectra before and after adsorption revealed that the morphologies of the samples differ. The analysis of the EDX spectra of the elemental composition of the samples after adsorption of CrО42- and Cr2О72- confirmed that they contain, in addition to the PAn elements, also chromium. The distribution of chemical elements in the samples after adsorption revealed that they are almost uniformly distributed surfaces, and the intensity of its signal on EDX spectra depends on the initial concentrations of oxyanion solutions CrО42- and Cr2О72-. The value of CrО42- adsorption by the PAn sample is almost twice as small as the value of Cr2О72- adsorption. By comparing the contents of atoms of elements, in particular sulfur (S) and oxygen (O), before and after adsorption, it was found that S is replaced by Cr, and the content of O slightly increases with an increase in the initial concentration of Cr(VI) in the solutions.

Synthesis of magnetic chitosan-composite biochar and its removal of copper ions (Cu2+) and methylene blue (MB) dye from aqueous solutions.

This study presents the synthesis and evaluation of a magnetic chitosan-modified biochar (M-BC-CS) composite, developed from waste maize straw, for the efficient removal of copper ions (Cu2+) and methylene blue (MB) dye from aqueous solutions. The composite was characterized using advanced techniques such as SEM, BET, FTIR, XPS, and XRD, confirming its enhanced surface area, porosity, and magnetic properties. The study is aimed at investigating the optimal conditions for adsorption of Cu2+ and MB by M-BC-CS through analysis of the influence of diverse adsorbent dosages, pH levels, reaction times, and initial solution concentrations. The findings demonstrated that the equilibrium duration for the adsorption of Cu2+ and MB by M-BC-CS was 60min, resulting in corresponding equilibrium adsorption quantities of 54.42mg/g and 67.23mg/g, respectively. To elucidate the adsorption mechanism, the present investigation applied the pseudo-second-order kinetic model and the Langmuir isotherm. The outcomes suggested that the adsorption process is attributable to single molecular layer chemisorption. XPS and FTIR analysis determined that ion exchange and electrostatic interactions are the predominant mechanisms responsible for the simultaneous adsorption of Cu2+ and MB, and a competitive relationship exists between these mechanisms. In addition, M-BC-CS exhibited exceptional magnetic separation performance, enabling effortless and effective separation when exposed to an external magnetic field. Furthermore, the results demonstrated that M-BC-CS has good reusability and high adsorption capacity also in real wastewater, thus emphasizing its potential as a promising adsorbent for the elimination of Cu2+ and MB from aqueous solutions.

Kinetic Adsorption Studies of Cationic Dyes onto Molecular Sieve and Activated Carbons

Background: Dye-containing wastewater causes irreparable damage to the ecological water system. Although adsorbents are widely used for treating wastewater containing dyes, the comparative investigation on these materials is still insufficient for their wide applications in the industries. Objective: With the aim of comparing efficient and fast adsorbent materials for cationic dyes, we analyzed and evaluated the adsorbents of the MCM-41 molecular sieve and activated carbons. Methods: The adsorption performance was studied on the common colored organics, such as cationic dyes of rhodamine B (RhB) and methylene blue (MB) dyes. The present work examined the impact of experimental variables, including initial dye concentration, adsorption time, and pH, on the adsorption process and performance, as well as the adsorption kinetics of the diverse adsorbents towards two cationic dyes. Results: MCM-41 molecular sieves showed relatively high adsorption capacity for RhB and AC-2, which made their adsorption capacity for MB much higher than that of MCM- 41 molecular sieves. A comprehensive analysis was conducted using pseudo-first-order and pseudo-second-order to decipher the mechanism of dye adsorption. The heterogeneous adsorption mechanism could explain the dye adsorption behavior of MCM-41 molecular sieve and activated carbons. Conclusion: The results demonstrated the influence of the pore structure and surface properties of the adsorbents on the adsorption capacity of dye molecules in an aqueous solution. For the initial concentration of cationic dye solutions of 20 mg/L, the MCM-41 molecular sieve had a MB adsorption capacity of 130.8 mg/g under alkaline conditions at pH=10, while the activated carbon adsorbents showed a stable MB adsorption capacity of 266.6 mg/g under different pH conditions, proving their applicability in treating wastewater containing dyes under different acid/base environments.

ADSORPTION OF TEXTILE DYE ACID GREEN 42 (AG42) ON ACTIVATED CARBON FROM CHICKEN EGGSHELLS (CAC30)

The present work is a contribution to the valorization of chicken eggshells, an abundant waste product in Cote dIvoire, as a credible alternative to commercial activated carbon.Chemicalactivation of the precursorwascarriedoutwith30%phosphoricacidfor24h of contactin a ratio of 200 g of material to 100 mL of acid, and calcined at 600°C for 1h. The surface of the activated carbon obtained was studied using the BET (Brunauer-Emmett and Teller) method, which consists in establishing the adsorption isotherm for nitrogen N2. The results reveal a specific surface area of 5.42 m2.g-1, 65.68% of micropores and a pHzc of 7.40. Chemical characteristics determined by Boehms method indicate the basic nature of the surface. The elemental composition is dominated by oxygen(50.53%),calcium(30.78%)andcarbon(11.33%).The experiments demonstrated that the removalof AG42by adsorption on CAC30 is influenced by contact time, activated carbon mass, solution pH, and initial concentration and temperature of the dye aqueous solution. Adsorption kinetics followed the pseudo-second-order model and the isotherm is described by the Langmuir model. The thermodynamic study revealed the spontaneous (ΔG < 0) and exothermic (ΔH < 0) nature of dye adsorption, with a well-organized distribution of dye molecules at the adsorption sites (∆S°< 0).

Efficiency of heat-treated sepiolite in the adsorption of Cd, Zn, and Co from aqueous solutions: A low-cost approach for wastewater treatment

This study investigated the adsorption of Cd, Co, and Zn ions onto unmodified and heat-treated sepiolite, focusing on the effect of contact time, initial pH, and heat pretreatments. Kinetic experiments were conducted in triplicate, and equilibrium experiments indicated that Co2+ had the highest adsorption preference, followed by Zn2+ and Cd2+. The adsorption efficiency for Co2+ significantly increased with higher initial pH, whereas Zn2+ and Cd2+ showed optimal adsorption at lower pH levels. Heat-treated sepiolite at 250 ℃ exhibited a higher surface area and adsorption capacity in comparison with unmodified and 150 ℃-treated sepiolite, which indicated the importance of heat pretreatment. The pseudo-second-order kinetic model better described the adsorption process, and it was confirmed chemisorption as the rate-limiting step. By increasing the contact time, adsorption rates enhanced, with equilibrium achieved within 480 min for all systems. Higher initial solute concentrations led to an increase in adsorption processes, with Co ions consistently showing higher adsorption efficiency in competitive multi-ionic solutions. Adsorption percentages varied with pH and thermal treatment, indicating the importance of these parameters in optimizing sepiolite’s adsorption capacity for heavy metal removal.

Adsorption Desulfurization of Simulated Diesel Fuel Using Graphene Oxide

Graphene oxide (GO) was synthesized from graphite powder by the improved Hammers method and used for the adsorption of organosulfur compound (dibenzothiophene, DBT) from model diesel fuel. FT-IR spectroscopy, X-ray diffraction, SEM, EDX, and BET were used to characterize the GO. Several factors, such as solution pH, initial DBT concentration, adsorption contact time, adsorption temperature, and adsorbent dosage were used to test the DBT removal efficiency. The results show that the maximum removal was 96.4% at pH = 5, initial solution concentration of 200 ppm, adsorption time of 45 min, temperature of 45C and adsorbent dosage of 0.4 g/25 mL.

Synergistic Degradation of Methylene Blue by Hydrodynamic Cavitation Combined with Hydrogen Peroxide/Vitamin C System.

In this study, a new combined process of hydrodynamic cavitation (HC) and a hydrogen peroxide/vitamin C (H2O2/Vc) system was proposed for the degradation of methylene blue (MB) in wastewater. An impact-jet hydraulic cavitator was used as the cavitation generation equipment, and H2O2/Vc was selected as a homogeneous oxidation system. The degradation characteristics of MB were investigated. The results showed that the degradation effect of HC in combination with the H2O2/Vc system was more effective than that of the individual HC or H2O2/Vc system. A maximum degradation rate of 87.8% was achieved under the following conditions: H2O2 concentration of 0.03 mol/L, Vc concentration of 0.021 mol/L, inlet pressure of 0.3 MPa, initial solution concentration of 4 μmol/L, solution volume of 150 mL, and reaction time of 10 min. The synergy index was 1.615, indicating a synergistic effect between the HC and H2O2/Vc system. The data of the hydroxyl radical (·OH) yield under the conditions of HC, the H2O2/Vc system, and the HC + H2O2/Vc system were fitted and analyzed. A correlation equation for ·OH yield was established, further revealing the synergistic mechanism of the HC and H2O2/Vc system. The intermediate products of MB degradation were detected based on LC-MS, and three possible degradation pathways of MB degradation were proposed. The combined process of HC and H2O2/Vc systems exhibited relatively low energy efficiency and operating cost, indicating that it was in line with the development direction of wastewater treatment.

Folic acid allergy and the role of the basophil activation test

Background: Despite the large use of folic acid supplements, there are very few cases of reported allergy. Clinical case: A 38-year-old woman, experienced palmoplantar pruritus, generalized urticaria, angioedema and conjunctival hyperemia, 30 minutes after the intake of a 5mg folic acid tablet. She was taken to the Emergency Department and on discharge was referred to the Allergy and Clinical Immunology Department, where the patient underwent a diagnostic workup. The Skin Prick Test (SPT) was positive for the 5mg/mL concentration and the Basophil Activation Test (BAT) was considered positive for both dilutions, from an initial solution concentration of 5mg/ml: 1/100 dil (CD63=9.03%; SI=10.1) and 1/160 dil (CD63=7.46%; SI=8.4). Discussion/ Conclusion: We report a patient with an immediate reaction to folic acid with positive SPT and BAT, which favors an IgE-mediated allergy. To our knowledge, this is the first case describing the use of a BAT in the diagnostic workup of folic acid allergy.

Deriving Flow Velocity and Initial Concentration From Liesegang‐Like Patterns

AbstractZebra rocks, characterized by their striking reddish‐brown stripes, rods, and spots of hematite (Fe‐oxide), showcase complex self‐organized patterns formed under far‐from‐equilibrium conditions. Despite their ease of recognition, the underlying mechanisms of pattern‐forming processes remain elusive. We introduce a novel advection‐dominated phase‐field model that effectively replicates the Liesegang‐like patterns observed in Zebra rocks. This numerical model leverages the concept of phase separation, a well‐established principle governing Liesegang phenomena in a two‐dimensional setting. Our findings reveal that initial solute concentration and fluid flow velocity are critical determinants in pattern morphologies. We quantitatively explain the spacing and width of a specific Liesegang‐like pattern category. Furthermore, the model demonstrates that vanishingly low initial concentrations promote the formation of oblique patterns, with inclination angles influenced by rock heterogeneity. Additionally, we establish a quantitative relationship between band thickness and geological parameters for orthogonal bands. This enables the characterization of critical geological parameters based solely on static patterns observed in Zebra rocks, providing valuable insights into their formation environments. The diverse patterns in Zebra rocks share similarities with morphologies observed on early Earth and Mars, such as banded iron formations and hematite spherules. Our model, therefore, offers a plausible explanation for the formation mechanisms of these patterns and presents a powerful tool for deciphering the geochemical environments of their origin.

Mixed ligand iso-reticular MOFs as integrated photo-catalytic adsorbents for the removal of bromo-phenol blue: Kinetics, thermodynamics and mechanistic study

The designing of mixed linker MOFs with identical framework structures and different chemical components provides opportunities for enhancing their inborn adsorption and photo-degradation performances. Herein, we synthesized zinc, copper, manganese, and cobalt-based iso-reticular MOFs via the solvothermal method using 2,5-furan dicarboxylic acid and 1,2-bis(4-pridyl) ethylene as green ligands. The synthesized MOFs were applied for the adsorption-assisted photo-catalytic decontamination of bromophenol blue (BPB) from wastewater without using any co-catalyst under visible light irradiation. Note-worthily, Cu-MOF (BUT-206-Cu) exhibits high adsorption capacity (299 mg/g) and removal efficiency (97 %), mainly owing to the high surface area (280 m2/g), opened porous structure, additional defective sites, efficient energy transfer, and excellent stability in aqueous, and acidic environments resulting from the strong co-ordination environment of the copper cations. The impact of key factors, including initial pH and concentration of the dye solution, on the adsorption and degradation efficiency of BUT-206-Cu was investigated. Moreover, trapping experiments and EPR results revealed that OH• and h+ were the main active species in the photocatalytic degradation of BPB. Adsorption and degradation kinetics of BPB were observed to obey pseudo-second-order and pseudo-first order models, respectively. The thermodynamics study revealed that the adsorption of BPB fitted the Langmuir model, and values of the ΔGads, ΔHads, and ΔSads revealed that the adsorption process is spontaneous, physical, and exothermic and leads to increased randomness in the system. BUT-206-Cu exhibited excellent reusability for up to five cycles, indicating its potential as an environmentally friendly integrated photocatalytic adsorbent for removing BPB from wastewater.

Adsorption Studies of Pb<sup>2+</sup>, Cu<sup>2+</sup> and Cr<sup>3+</sup> from Aqueous Solution Using <i>Azadirachta Indica </i>(Neem) Seed Husk and <i>Adansonia Digitata </i>(Baobab) Seeds

The adsorption of Pb<sup>2+</sup>, Cu<sup>2+</sup> and Cr<sup>3+</sup> from aqueous solution using Neem seed husk (NSH) and baobab seed (BS) were studied through the use of batch adsorption system. The adsorbents were prepared by drying at 120°C for 24hours and were characterized using FT-IR, XRD, and SEM analysis. The FTIR spectroscopy revealed the presence of O-H, N-H, C-H, C=C, C=O, and C-O stretching; XRD revealed the particle sizes as 44.51nm for NSH and 42.61nm while the morphology of the NSH and BS were revealed by SEM to be porous for NSH and BS. Various parameters such as, initial metal ion concentration, adsorbent dosage, contact time, Temperature and pH of metal ion solution were investigated in a batch-adsorption System. The adsorption uptake was found to increase with increase in adsorbent dose, contact time and temperature but decreases with the initial concentration. The uptake of the metal ions increases and reaches optimum at pH of 4-6. The maximum adsorption capacity was found to be Pb-NSH (15.267mg/g) and Cu-NSH (19.46mg/g). Adsorption of Cu<sup>2+</sup>onto NSH fitted Langmuir isotherm model with (R<sup>2</sup> > 0.93) while Adsorption of Pb-NSH Fitted Freundlich isotherm Model with (R<sup>2</sup>> 0.99). Kinetic data fitted pseudo-second-order model (R<sup>2</sup> > 0.98) which was more suitable in explaining the adsorption rate. Thermodynamic data showed that Gibb’s free energy (ΔG°) values for all metal ions were negative indicating feasibility and favorability of adsorption. Positive enthalpy change (ΔH°) and Entropy change (ΔS°) values indicate endothermic processes and increase in randomness.

Determination of interdiffusion coefficients in single crystal superalloys based on solute distribution at the dendritic scale using the Gaussian solution model

Since the initial solute concentration distribution of the sinusoidal solution model shows a significant deviation from the actual concentration distribution of nickel-based single crystal (SX) superalloy dendrites, it is limited to calculate the diffusion coefficient of SX in the homogenization treatment. Therefore, this work proposes a new Gaussian solution model to calculate the diffusion coefficients and the diffusion activation energy of alloying elements in SX superalloy at high temperatures. The diffusion activation energies of W, Ta, and Ti elements in the studied alloy are consistent with the results from other works. This model could more accurately determine the diffusion coefficient of elements during the dendrite homogenization process of SX superalloys since it reflects actual physical processes. Moreover, it has the potential to use in various alloy systems and contributes to the formulation of effective homogenization treatments.