Displaying publications 441 - 460 of 944 in total

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  1. Effective adsorption of cadmium and lead using SO3H-functionalized Zr-MOFs in aqueous medium
    Gul S, Ahmad Z, Asma M, Ahmad M, Rehan K, Munir M, et al.
    Chemosphere, 2022 Nov;307(Pt 1):135633.
    PMID: 35810866 DOI: 10.1016/j.chemosphere.2022.135633
    Cadmium (Cd) and Lead (Pb) from industrial wastewater can bioaccumulate in the living organisms of water bodies, posing serious threats to human health. Therefore, efficient remediation of heavy metal ions of Cd (II) and Pb (II) in aqueous media is necessary for public health and environmental sustainability. In the present study, water stable Zirconium (Zr) based metal organic frameworks (MOFs) with SO3H functionalization were synthesized by solvothermal method and used first time for the adsorption of Cd (II) and Pb (II). Synthesis of UiO-66-SO3H, nano-sized (<100 nm) MOFs, was confirmed by FTIR, XRD, FESEM and BET. Effects of contact time, pH and temperature were investigated for adsorption of Cd (II) and Pb (II) onto SO3H-functionalized Zr-MOFs. The UiO-66-SO3H displayed notable rejections of 97% and 88% towards Cd (II) and Pb (II), respectively, after 160 min at 25 °C and pH (6) with an initial concentration of 1000 mg/L. Adsorption capacities of Cd (II) and Pb (II) were achieved as 194.9154 (mg/g) and 176.6879 (mg/g), respectively, at an initial concentration of 1000 mg/L. The Pseudo second-order kinetic model fitted well with linear regression (R2) of value 1. The mechanism was confirmed mainly as a chemisorption and coordination interaction between sulfone group (-SO3H) and metal ions Cd (IIa) and Pb (II). These results may support effective adsorption and can be studied further to enrich and recycle other heavy metals from wastewater.
    Matched MeSH terms: Kinetics
  2. Bio-inspired magnetic chitosan/Iron oxide macromolecules for multiple anionic dyes adsorption from aqueous media
    Vijayasree VP, Abdul Manan NS
    Int J Biol Macromol, 2024 Oct;277(Pt 1):134103.
    PMID: 39047997 DOI: 10.1016/j.ijbiomac.2024.134103
    Organic anionic dyes are major water pollutants due to their low degradability caused by complex aromatic structures. Not only do they exert toxic, mutagenic, teratogenic, tumorigenic, and genotoxic effects, but they also decrease fertility and cause irritation to the skin and respiratory system in humans. This long-term toxicity has detrimental effects on aquatic organisms and their surroundings, resulting in an imbalanced ecosystem. In this study, a Cs@Fe3O4 magnetic biosorbent was synthesised to uptake three anionic dyes and characterised for FTIR, BET/BJH, XRD, TGA, VSM, and FESEM analyses. The biosorbent average surface area was confirmed to be 52.6524 m2/g, with average pore sizes of 7.3606 nm and 6.9823 nm for adsorption-desorption processes, respectively. Batch adsorption studies pH values, contact times, temperature, initial dye concentrations, and adsorbent dosages were examined. Several isotherm and kinetic models were studied to determine the adsorption mechanism. The adsorption data of these dyes at equilibrium was observed to match Langmuir's isotherm and pseudo-second-order kinetic models. The thermodynamic study revealed that the adsorption process for these dyes was an exothermic reaction. Maximum adsorption capacities for congo red, methyl orange, and metanil yellow were 117.77 mg/g, 137.77 mg/g, and 155.57 mg/g, respectively. The reusability of recovered Cs@Fe3O4 after dye adsorption was evaluated up to five continuous adsorption-desorption cycles for its possible industrial applications.
    Matched MeSH terms: Kinetics
  3. Production of eco-friendly adsorbent of kaolin clay and cellulose extracted from peanut shells for removal of methylene blue and congo red removal dyes
    Reghioua A, Atia D, Hamidi A, Jawad AH, Abdulhameed AS, Mbuvi HM
    Int J Biol Macromol, 2024 Apr;263(Pt 1):130304.
    PMID: 38382796 DOI: 10.1016/j.ijbiomac.2024.130304
    This present work targets the production of an eco-friendly adsorbent (hereinafter KA/CEL) from kaolin clay functionalized with cellulose extract obtained from peanut shells. The adsorbents were used for decolorization of two different types of organic dyes (cationic: methylene blue, MB; anionic: Congo red, CR) from an aqueous environment. Several analytical methods, including Brunauer-Emmett-Teller (surface properties), Fourier Transforms infrared (functionality), scanning electron microscope, Energy dispersive X-Ray (morphology), and pHpzc test (surface charge), were used to attain the physicochemical characteristics of KA/CEL. The Box-Behnken Design (BBD) was applied to determine the crucial factors affecting adsorption performance. These included cellulose loading at 25 %, an adsorbent dose of 0.06 g, solution pH set at 10 for MB and 7 for CR, a temperature of 45 °C, and contact times of 12.5 min for MB and 20 min for CR dye. The adsorption data exhibited better agreement with the pseudo-second-order kinetic and Freundlich models. The Langmuir model estimated the monolayer capacity to be 291.5 mg/g for MB and 130.7 mg/g for CR at a temperature of 45 °C. This study's pivotal finding underscores the promising potential of KA/CEL as an effective adsorbent for treating wastewater contaminated with organic dyes.
    Matched MeSH terms: Kinetics
  4. Enhanced photocatalytic regeneration of carboxymethyl cellulose/lignin/ZnO complex hydrogel after methylene blue adsorption
    Fu J, Yap JX, Leo CP, Chang CK
    Int J Biol Macromol, 2024 Aug;274(Pt 2):133510.
    PMID: 38960270 DOI: 10.1016/j.ijbiomac.2024.133510
    The biodegradable, nontoxic, and renewable carboxymethyl cellulose (CMC) hydrogel has been developed into a green adsorbent. However, the weak chemical interaction limits its adsorption capability and reusability. This work incorporated lignin with complex structure and ZnO nanoparticles with photocatalytic properties into CMC hydrogel beads to improve the removal of methylene blue (MB) through chemical interaction. Scanning electron microscopic images and Fourier-transform infrared spectra confirmed the compatibility between lignin and ZnO nanoparticles as well as the increment of active sites for dye removal. The MB adsorption on CMC hydrogel beads was more significantly affected by the temperate and initial concentration compared to contact time, pH, and adsorbent dosage. The MB adsorption capacity of CMC hydrogel was improved to 276.79 mg/g after incorporating lignin and ZnO nanoparticles. The adsorption followed the pseudo-second-order kinetic model and Langmuir isotherm model, indicating chemical adsorption. After 6 cycles, the adsorption capacity was reduced by about 15 %. The UV irradiation could recover and improve MB adsorption capacity of CMC hydrogel beads containing ZnO nanoparticles due to the introduction of reactive oxygen species.
    Matched MeSH terms: Kinetics
  5. Enzymatic preparation of diacylglycerols: lipase screening, immobilization, characterization and glycerolysis performance
    Xie R, Peng X, Lee YY, Xie P, Tan CP, Wang Y, et al.
    J Sci Food Agric, 2025 Jan 30;105(2):816-828.
    PMID: 39258418 DOI: 10.1002/jsfa.13872
    BACKGROUNDS: Glycerolysis, with its advantages of readily available raw materials, simple operation, and mild reaction conditions, is a primary method for producing diacylglycerol (DAG). However, enzymatic glycerolysis faces challenges such as high enzyme costs, low reuse efficiency, and poor stability. The study aims to develop a cost-effective immobilized enzyme by covalently binding lipase to pre-activated carriers through the selection of suitable lipases, carriers, and activating agents. The optimization is intended to improve the glycerolysis reaction for efficient DAG production.

    RESULTS: Lipase CN-TL (from Thermomyces lanuginosus) was selected through glycerolysis reaction and molecular docking to catalyze the glycerolysis reaction. Optimizing the immobilization method by covalently binding CN-TL to poly(ethylene glycol) diglycidyl ether (PEGDGE)-preactivated resin LX-201A resulted in the preparation of the immobilized enzyme TL-PEGDGE-LX. The immobilized enzyme retained over 90% of its initial activity after five consecutive reactions, demonstrating excellent reusability. The DAG content in the product remained at 84.8% of its initial level, further highlighting the enzyme's potential for reusability and its promising applications in the food and oil industries.

    CONCLUSIONS: The immobilized lipase TL-PEGDGE-LX, created by covalently immobilizing lipase CN-TL on PEGDGE-preactivated carriers, demonstrated broad applicability and excellent reusability. This approach offers an economical and convenient immobilization strategy for the enzymatic glycerolysis production of DAG. © 2024 Society of Chemical Industry.

    Matched MeSH terms: Kinetics
  6. Advancement of lignin into bioactive compounds through selective organic synthesis methods
    Jadhav P, Bhuyar P, Misnon II, Rahim MHA, Roslan R
    Int J Biol Macromol, 2024 Sep;276(Pt 2):134061.
    PMID: 39043289 DOI: 10.1016/j.ijbiomac.2024.134061
    The conversion of lignin into bioactive compounds through selective organic synthesis methods represents a promising frontier in the pursuit of sustainable raw materials and green chemistry. This review explores the versatility of lignin-derived bioactive compounds, ranging from their application in drug discovery to their role in the development of biodegradable materials. Despite notable advancements, the synthesis routes and yields of highly bioactive molecules from lignin still require further exploration and improvement. This review provides an in-depth examination of the progress made in understanding the complex structure of lignin and developing innovative approaches to exploit its potential. Specifically, the types of lignins covered include softwood Kraft lignin, hardwood organosolv lignin, and soda lignin. This work is divided into three parts: first, the transformation of lignin into bioactive molecules with chemically active centres and functionalised hydroxyl groups through depolymerisation; second, kinetic modelling techniques essential for understanding the chemical kinetics of lignin and enabling significant scaling up in the conversion of organic molecules; third, efficient catalytic pathways for synthesising molecules with anticancer and antibacterial properties. In conclusion, this comprehensive review spurs further investigations into lignin-derived bioactive compounds, their applications, and the advancement of sustainable processes.
    Matched MeSH terms: Kinetics
  7. Waste newspaper as cellulose resource of activated carbon by sodium salts for methylene blue and congo red removal
    Hao YS, Othman N, Zaini MAA
    Int J Biol Macromol, 2024 Oct;277(Pt 4):134353.
    PMID: 39089559 DOI: 10.1016/j.ijbiomac.2024.134353
    The work was aimed at evaluating the adsorptive properties of waste newspaper (WN) activated carbons chemically produced using sodium salts for methylene blue (MB) and congo red (CR) removal. The activated carbons, designated as AC1, AC2, AC3 and AC4 were prepared through impregnation with NaH2PO4, Na2CO3, NaCl and NaOH, respectively and activation at 500 °C for 1 h. The activated carbons were characterized for surface chemistry, thermal stability, specific area, morphology and composition. The AC1 with a surface area of 917 m2/g exhibits a greater MB capacity of 651 mg/g. Meanwhile, a greater CR capacity was recorded by AC2 at 299 mg/g. The pseudo-second order model fitted well with the kinetic data, while the equilibrium data could be described by Langmuir model. The thermodynamic parameters, i.e.., positive ΔH°, negative ΔG° and positive ΔS° suggest that the adsorption of dyes is endothermic, spontaneous and feasible at high solution temperature. To conclude, WN is a potential cellulose source for producing activated carbon, while NaH2PO4 activation could be employed to convert WN into activated carbon for effective dye wastewater treatment.
    Matched MeSH terms: Kinetics
  8. Efficient removal of low concentrations of copper and lead ions in water using chitosan-condensed tannin composite microspheres
    Wang L, Chen X, Xi X, Lee SH, Lum WC, Huang Y, et al.
    Int J Biol Macromol, 2024 Dec;282(Pt 6):137438.
    PMID: 39528202 DOI: 10.1016/j.ijbiomac.2024.137438
    Condensed tannin was solidified onto chitosan microspheres to prepare chitosan-tannin (CT) composite microspheres with a simple preparation method to study its performance in adsorbing copper (Cu2+) and lead ions (Pb2+) in aqueous media. The study investigated the influence of the mass ratio of tannin and chitosan, pH value, adsorption time, and initial concentrations of Cu2+ and Pb2+ on the adsorption capacity of Cu2+ and Pb2+ ions. Additionally, the study examined the adsorption isotherms and kinetics of Cu2+ and Pb2+ on CT composite microspheres. The adsorption process aligns more closely with the fitting results of the Langmuir model. The maximum capacity for saturated monolayer adsorption of CT composite microspheres for Cu2+ and Pb2+ was 37.6 and 52.9 mg/g, respectively. The adsorption process of CT composite microspheres for Cu2+ and Pb2+ was primarily driven by single-layer chemical adsorption. In addition, metal ions adsorbed onto CT composite microspheres can be released by treating them with a dilute solution of strong acid. Furthermore, the CT composite microspheres exhibited impressive removal efficiencies of 82 % and 95 % for Cu2+ and Pb2+ respectively, even at low concentrations of 2 mg/L. The CT composite microspheres have the ability to easily separate the adsorbed Cu2+ and Pb2+ ions.
    Matched MeSH terms: Kinetics
  9. Design of composite chitosan/algae/zeolite by freeze- or air-drying: A comparative adsorbent analysis for optimized removal of brilliant green dye
    Suhaimi A, Jawad AH, Yusoff MZM, Wilson LD, ALOthman ZA
    Int J Biol Macromol, 2025 Feb;288:138650.
    PMID: 39674466 DOI: 10.1016/j.ijbiomac.2024.138650
    A bio-composite material was developed that contains chitosan, food-grade algae, and zeolite for the removal of brilliant green (BG) dye. The synthesized bio-composite was dried via two different methods (air-drying; AD, and freeze-drying; FD). The physicochemical characterization of air-dried chitosan-algae-zeolite (Cs-Alg-Zl-AD) and freeze-dried chitosan-algae-zeolite (Cs-Alg-Zl-FD) were investigated by spectroscopy (FTIR, SEM-EDX, and XPS), diffraction (XRD), surface charge via pHpzc, specific surface area (SSA) and elemental analyses. The utilization of Box-Behnken Design (BBD) was intended to optimize the three input variables, which are adsorbent dosage, pH of medium, and contact time. The adsorption optimization process yielded optimal conditions, which were verified through a desirability test and implemented in batch-mode equilibrium experiments. The Cs-Alg-Zl-FD has a higher specific surface area (SSA = 3.29 m2/g) compared to Cs-Alg-Zl-AD (SSA = 1.79 m2/g). The Cs-Alg-Zl-FD shows greater adsorptive removal of BG (98.6 %) over Cs-Alg-Zl-AD (88.6 %), in parallel agreement with differences in the SSA. Moreover, the maximum BG dye adsorption capacities of Cs-Alg-Zl-FD (119.5 mg/g) and Cs-Alg-Zl-AD (108 mg/g) at pH = 8.1 and 25 °C. The Freundlich model fits best with Cs-Alg-Zl-AD while Langmuir and Temkin models account for the Cs-Alg-Zl-FD dye adsorption. The Cs-Alg-Zl-FD shows greater dye adsorption over four adsorption cycles, as compared with the Cs-Alg-Zl-AD.
    Matched MeSH terms: Kinetics
  10. Adsorption isotherms, kinetics, and thermodynamics of Au(III) on chitosan/palm kernel fatty acid distillate/magnetite nanocomposites
    Chang SH, Jampang AOA, Din ATM
    Int J Biol Macromol, 2025 Apr;304(Pt 1):140913.
    PMID: 39938848 DOI: 10.1016/j.ijbiomac.2025.140913
    This study examined the adsorption isotherms, kinetics, and thermodynamics of Au(III) onto chitosan/palm kernel fatty acid distillate/magnetite nanocomposites (CPMNs) to enhance the understanding of adsorption behavior and mechanisms. Adsorption experiments were conducted across various initial Au(III) concentrations, contact times, and temperatures. The experimental data were analyzed using nonlinear isotherm and kinetic models, and thermodynamic parameters were evaluated. The results revealed that the Langmuir model best fits the adsorption equilibrium data, showing a maximum monolayer adsorption capacity of 1.102-1.163 mmol/g (217-229 mg/g). The pseudo-first-order model best describes the kinetic data, suggesting first-order kinetics and a physisorption-dominated process. Thermodynamic analysis indicated that the adsorption is spontaneous, endothermic, entropy-driven, and highly favorable, primarily governed by physisorption. This study provides significant insights into the adsorption mechanisms of CPMNs for Au(III), contributing to advancing cost-effective and eco-friendly adsorbents for industrial use, such as wastewater treatment and metal recovery in mining, metallurgy, and electronic waste recycling industries.
    Matched MeSH terms: Kinetics
  11. Enhancing fish sludge bioconversion kinetics for nutrient recovery in aquaponics using a modified biological aerated filter with a novel media of polyhedral hollow spheres
    Chen A, Zhang H, Zi Y, Gao Y, Lee CT, Li C
    J Environ Manage, 2025 Jan;373:123709.
    PMID: 39724672 DOI: 10.1016/j.jenvman.2024.123709
    Nutrient recovery from aquaculture sludge is vital for promoting hydroponic plant growth and achieving near-zero solid waste discharge in aquaponic systems. Modified biological aerated filters (MBAFs) are promising because of the dual capabilities of aquaculture sludge collection and aerobic mineralization. However, the bioconversion kinetics, which is indirectly related to the packed media, need to be improved. In this study, a novel polyhedral hollow sphere (PHS) medium was used in an MBAF (MBAF-PHS) to overcome the shortcomings of the current medium, facilitating fish sludge retention and enhancing subsequent bioconversion kinetics for nutrient recovery. An average rate of 36.9 g/d for dry weight of fish sludge was achieved during 29 d of filtration and an average reduction rate of 31.30 g/d during 26 d of bioconversion. The total mass of fish sludge was converted by 76.2% via the co-action of the solubilization of organic solids and degradation of dissolved organic matter. MBAF-PHS was competitive for macronutrient recovery compared with the MBAF-sponge previously used. The ratios of the final concentrations of the macronutrients (P, Mg, and S) to the concentrations in Hoagland solution (Cf/CH, %) were 278.1, 162.8, and 200.9%, respectively, whereas the ratios of N, K, and Ca were 65.9, 37.1, and 51.0%, respectively. High bioconversion kinetics of NO3--N and PO43--P were obtained within 7 d with an MNO3-N/MTN of 79.9% and MPO4-P/MDTP of 80.3%. The nutrient bioconversion of fish sludge was associated with the diversity of the microbial community in the MBAF-PHS, especially the population of nitrogen-removing microbial species that developed after 9 d of mineralization.
    Matched MeSH terms: Kinetics
  12. Adsorption of sulfamethoxazole in an aqueous environment onto a novel magnetic sporopollenin-cellulose triacetate
    Saheed IO, Ying LR, Yaacob SFFS, Hanafiah MAKM, Latip AFA, Suah FBM
    Int J Biol Macromol, 2025 Mar;296:139787.
    PMID: 39809393 DOI: 10.1016/j.ijbiomac.2025.139787
    Antibiotics are emerging environmental contaminants posing critical health risks due to their tendency to concentrate in living things and eventually infiltrate the human body. Sulfamethoxazole (SMZ) is among the commonly detected antibiotics in wastewater requiring effective removal approach. A sustainable, thermally stable and easily separable magnetic sporopollenin-cellulose triacetate (Msp-CTA) was developed via a simple step synthesis for eliminating SMZ from aqueous solution. The assessment of Msp-CTA characteristics via instrumentations revealed a mesoporous adsorbent having COO-, -OH, CO, and Fe - O as its potential adsorption binding sites. Improved stability gained from blending sporopollenin (Sp) and cellulose triacetate (CTA) was affirmed through TGA analysis. Minimal competition for the adsorption sites by H+ and OH- favours efficient SMZ adsorption onto Msp-CTA at pH 3 and 5 with %removal of 78.7 and 83.1 %, respectively, using 40 mg/L initial SMZ concentration. The monolayer adsorption capacities 15.14 and 15.52 mg/g were obtained from nonlinear and linear Langmuir isotherms, respectively. The adsorption process is best described by Temkin > Hill > Langmuir > Freundlich isotherms based on proximity of correlation coefficient R2 to 1. The best fit to Temkin suggests that SMZ adsorption's energy decreases proportionally with increasing surface coverage of Msp-CTA. The adsorption process is arbitrated to conform best to pseudo-second order (PSO) kinetic, though a bias is perceived in the linear fitting. Msp-CTA shows reusable potential with 65.9 % desorption at third cycle. The thermodynamic studies revealed an endothermic process. Hence, Msp-CTA demonstrates potential as an alternative adsorbent for sulfonamide-based antibiotics' removal from wastewater.
    Matched MeSH terms: Kinetics
  13. Cross-linked chitosan/pencil clay hybrid beads for the adsorption of reactive black 5
    Khanday WA, Soon KA, Ahmed MJ, Hummadi EH
    Int J Biol Macromol, 2025 Jan;285:138301.
    PMID: 39638171 DOI: 10.1016/j.ijbiomac.2024.138301
    Chitosan (CH) and pencil clay (CL) were utilized to prepare stable epichlorohydrin cross-linked chitosan-clay hybrid beads (CCHB) for the adsorptive removal of anionic reactive black 5 (RB5) dye. Among various percentage weight ratios of chitosan/clay hybrid beads, 40 % CH-60 % CL was selected as the best adsorbent owing to its stability and removal efficiency. The pore properties of CCHB in terms of surface area, total pore volume, and average pore width were 40.33 m2/g, 0.088 cm3/g, and 86.06 Å, respectively. The adsorption behavior of RB5 on CCHB followed Langmuir and pseudo-second-order models. Thermodynamic parameters confirm the endothermic and spontaneous nature of RB5 adsorption and the regeneration studies reveal a negligible decrease in removal efficiency of CCHB after 5 adsorption-desorption cycles. The CCHB exhibited adsorption capacities of 169.49, 200.00, and 227.27 mg/g for RB5, respectively, at 30, 40, and 50 °C. The prepared chitosan-clay hybrid bead adsorbent can be efficiently applied for anionic wastewater treatment.
    Matched MeSH terms: Kinetics
  14. Lipase-catalyzed esterification for efficient acylglycerols synthesis in a solvent-free system: Process optimization, mass transfer insights and kinetic modeling
    Zou S, Zhang Z, Lee YY, Ai H, Zhang Y, Wang Y
    Food Chem, 2025 May 15;474:143151.
    PMID: 39891972 DOI: 10.1016/j.foodchem.2025.143151
    Acylglycerols are widely used in the food industry due to their antimicrobial, emulsifying and nutritional properties. This study investigated the key reaction parameters, mass transfer mechanisms, and kinetic features of lipase-catalyzed esterification in a solvent-free system. Taguchi method was further employed to explore the relationship between "reaction parameter - yield composition". The results revealed that the maximum selectivity were achieved fror MAG (57.72 %), DAG (82.67 %) and TAG (79.29 %) under different enzymatic conditions. Fatty acid-to-glycerol molar ratio had the greatest impact on DAG selectivity, contributing 38.08 % of total impact level. Mass transfer analysis showed that external mass transfer limitation could be effectively overcome at stirring speeds above 600 rpm. Kinetic analysis confirmed that the reaction followed the Ping-Pong BiBi mechanism with alcohol and acid inhibition (SSE = 0.000643). This work provided a theoretical basis for developing more efficient and selective catalytic processes, aiding in quality control, reactor design, and industrial scale-up.
    Matched MeSH terms: Kinetics
  15. Adsorption of methylene blue dye from aqueous solution using low-cost adsorbent: kinetic, isotherm adsorption, and thermodynamic studies
    Al-Asadi ST, Al-Qaim FF, Al-Saedi HFS, Deyab IF, Kamyab H, Chelliapan S
    Environ Monit Assess, 2023 May 16;195(6):676.
    PMID: 37188926 DOI: 10.1007/s10661-023-11334-2
    Fig leaf, an environmentally friendly byproduct of fruit plants, has been used for the first time to treat of methylene blue dye. The fig leaf-activated carbon (FLAC-3) was prepared successfully and used for the adsorption of methylene blue dye (MB). The adsorbent was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and the Brunauer-Emmett-Teller (BET). In the present study, initial concentrations, contact time, temperatures, pH solution, FLAC-3 dose, volume solution, and activation agent were investigated. However, the initial concentration of MB was investigated at different concentrations of 20, 40, 80, 120, and 200 mg/L. pH solution was examined at these values: pH3, pH7, pH8, and pH11. Moreover, adsorption temperatures of 20, 30, 40, and 50 °C were considered to investigate how the FLAC-3 works on MB dye removal. The adsorption capacity of FLAC-3 was determined to be 24.75 mg/g for 0.08 g and 41 mg/g for 0.02 g. The adsorption process has followed the Langmuir isotherm model (R2 = 0.9841), where the adsorption created a monolayer covering the surface of the adsorbent. Additionally, it was discovered that the maximum adsorption capacity (Qm) was 41.7 mg/g and the Langmuir affinity constant (KL) was 0.37 L/mg. The FLAC-3, as low-cost adsorbents for methylene blue dye, has shown good cationic dye adsorption performance.
    Matched MeSH terms: Kinetics
  16. Eco-friendly and cost-effective adsorbent derived from blast furnace slag with black liquor waste for hazardous remediation
    Naggar AH, Dhmees A, Seaf-Elnasr TA, Chong KF, Ali GAM, Ali HM, et al.
    Environ Sci Pollut Res Int, 2024 Jan;31(3):3872-3886.
    PMID: 38093080 DOI: 10.1007/s11356-023-31453-0
    The current investigation concerns with preparation eco-friendly and cost-effective adsorbent (mesoporous silica nanoparticles (SBL)) based on black liquor (BL) containing lignin derived from sugarcane bagasse and combining it with sodium silicate derived from blast furnace slag (BFS) for thorium adsorption. Thorium ions were adsorbed from an aqueous solution using the synthesized bio-sorbent (SBL), which was then assessed by X-ray diffraction, BET surface area analysis, scanning electron microscopy with energy dispersive X-ray spectroscopy (EDX), and Fourier transforms infrared spectroscopy (FTIR). Th(IV) sorption properties, including the pH effect, uptake rate, and sorption isotherms across various temperatures were investigated. The maximum sorption capacity of Th(IV) on SBL is 158.88 mg/L at pH value of 4328 K, and 60 min contact time. We demonstrated that the adsorption processes comport well with pseudo-second-order and Langmuir adsorption models considering the kinetics and equilibrium data. According to thermodynamic inspections results, the Th(IV) adsorption process exhibited endothermic and random behavior suggested by positive ΔH° and ΔS° values, while the negative ΔG° values indicated a spontaneous sorption process. The maximum Th(IV) desorption from the loaded SBL (Th/SBL) was carried out at 0.25 M of NaHCO3 and 60 min of contact. Sorption/desorption processes have five successive cycles. Finally, this study suggests that the recycling of BFS and BL can be exploited for the procurement of a promising Th(IV) adsorbents.
    Matched MeSH terms: Kinetics
  17. Syntheses, in vitro, and in silico studies of rhodanine-based schiff bases as potential α-amylase inhibitors and radicals (DPPH and ABTS) scavengers
    Egu SA, Ali I, Khan KM, Chigurupati S, Qureshi U, Salar U, et al.
    Mol Divers, 2023 Apr;27(2):767-791.
    PMID: 35604512 DOI: 10.1007/s11030-022-10454-0
    A two-step reaction method was used to synthesize a series of rhodanine-based Schiff bases (2-33) that were characterized using spectroscopic techniques. All compounds were assessed for α-amylase inhibitory and radical scavenging (DPPH and ABTS) activities. In comparison to the standard acarbose (IC50 = 9.08 ± 0.07 µM), all compounds demonstrated good to moderate α-amylase inhibitory activity (IC50 = 10.91 ± 0.08-61.89 ± 0.102 µM). Compounds also demonstrated significantly higher DPPH (IC50 = 10.33 ± 0.02-96.65 ± 0.03 µM) and ABTS (IC50 = 12.01 ± 0.12-97.47 ± 0.13 µM) radical scavenging activities than ascorbic acid (DPPH, IC50 = 15.08 ± 0.03 µM; ABTS, IC50 = 16.09 ± 0.17 µM). The limited structure-activity relationship (SAR) suggests that the position and nature of the substituted groups on the phenyl ring have a vital role in varying inhibitory potential. Among the series, compounds with an electron-withdrawing group at the para position showed the highest potency. Kinetic studies revealed that the compounds followed a competitive mode of inhibition. Molecular docking results are found to agree with experimental findings, showing that compounds reside in the active pocket due to the main rhodanine moiety.
    Matched MeSH terms: Kinetics
  18. Fabrication of calix[4]arene/polyurethane for the adsorptive removal of cationic dye from aqueous solutions
    Ishak S, Rosly NZ, Abdullah AH, Alang Ahmad SA
    Environ Monit Assess, 2023 Oct 12;195(11):1303.
    PMID: 37828347 DOI: 10.1007/s10661-023-11909-z
    Calix[4]arene/polyurethane (C4PU) has been synthesized and characterized as an alternative adsorbent for the adsorption of methylene blue (MB) and malachite green (MG) dyes from the aqueous solution. C4PU was synthesized by reacting p-tert-butyl calix[4]arene with hexamethylene diisocyanate (HMDI) as the cross-linking agent. Different polymer ratios were synthesized, and C4PU-4 shows better adsorption than other ratios. The polymer was characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET) analysis, and point of zero charges (pHPZC). The isotherms and kinetics of the adsorption of MB and MG were studied under a range of experimental conditions, including pH, adsorbent dosage, initial dye concentration, and contact time. The adsorption was determined by the adsorption percentage of MB and MG dyes from the solution. The Langmuir isotherm model best describes the adsorption process for both dyes, and it follows a pseudo-second-order kinetic model, with the maximum adsorption capacity (qmax) of MB and MG, respectively, was found to be 1.991 mg·g-1 and 2.240 mg·g-1.
    Matched MeSH terms: Kinetics
  19. Plant-mediated synthesis of silver-doped ZnO nanoparticles with high sonocatalytic activity: Sonocatalytic behavior, kinetic and thermodynamic study
    Chan YY, Pang YL, Lim S, Chong WC, Shuit SH
    Environ Sci Pollut Res Int, 2024 Jun;31(28):40495-40510.
    PMID: 36417069 DOI: 10.1007/s11356-022-24145-8
    Together with the rapid growth of technology, the discharge of wastewater from industry into environment had become a hot topic among society nowadays. More attention had been given to the development of water treatment techniques. In this study, sonocatalysis was proposed to degrade the organic pollutants using silver-doped zinc oxide (Ag-ZnO) nanoparticles which were synthesized via green synthesis process using Clitoria ternatea Linn (Asian Pigeonwings flower). The characterization results revealed that the incorporation of Ag into the ZnO lattice decreased the crystallite size and increased the specific surface area of ZnO nanoparticles. It is noteworthy that about 98% of sonocatalytic degradation efficiency of malachite green (MG) was successfully achieved within 30 min in the presence of 5 wt.% Ag-ZnO with 1.0 g/L of catalyst loading under 500 mg/L of initial dye concentration, 80 W of ultrasonic power, 45 kHz of ultrasound frequency, and 2.0 mM of oxidant concentration. The kinetic study showed that the sonocatalytic degradation of organic dye was fitted well into second-order kinetic model with high R2 value (0.9531). In the thermodynamic study, negative value of standard Gibbs free energy and low value of activation energy (+ 24.43 kJ/mol) were obtained in the sonocatalytic degradation of MG using the green-synthesized Ag-ZnO sample. HIGHLIGHTS: • Facile synthesis of silver-doped zinc oxide nanoparticles using plant extract which act as reducing and stabilizing agents • Optical, physical, and chemical characterization of green-synthesized nanomaterials were performed • Evaluation of sonocatalytic degradation of organic dye using green-synthesized nanomaterials • Sonocatalytic behavior, kinetic and thermodynamic studies of sonocatalytic reaction.
    Matched MeSH terms: Kinetics
  20. Surface display of aspartate ammonia-lyase from Lactobacillus paracasei on Pichia pastoris
    Chang CC, Huang YH, Fu HK, Chang KW, Chen SH, Yu YT, et al.
    World J Microbiol Biotechnol, 2025 Apr 15;41(4):136.
    PMID: 40232580 DOI: 10.1007/s11274-025-04360-4
    This study explores the surface display of Lactobacillus paracasei aspartate ammonia-lyase (LpAAL) on Pichia pastoris using glycosylphosphatidylinositol (GPI) anchoring technology. LpAAL, an enzyme with broad substrate specificity, has significant potential in various industries, including food, pharmaceuticals, and cosmetics, due to its ability to catalyze the conversion of L-aspartate into fumarate and other related reactions. The surface-displayed LpAAL on yeast (yLpAAL) demonstrated improved stability, especially under high temperature and alkaline conditions, making it suitable for industrial processes that demand robust and stable enzymes. Kinetic analysis revealed a slight increase in Km value (6.3 mM) for yLpAAL comparing to free LpAAL (5.9 mM), reflecting reduced substrate affinity, but without a notable impact on overall efficiency. Additionally, yLpAAL exhibited enhanced storage stability and reusability, maintaining over 85% of its activity after six consecutive cycles. We successfully demonstrate the surface display technology to enhance enzyme performance by yLpAAL, offering a promising strategy for industries requiring durable and efficient enzymes in challenging environments.
    Matched MeSH terms: Kinetics
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