Fabrication and Adsorption Behavior of Magnesium Silicate Hydrate Nanoparticles towards Methylene Blue

Study on the Performance and Mechanism of Glass Fiber-Reinforced MgO-SiO2-H2O Cement

The magnesium silicate hydrate system (MgO-SiO2-H2O) possesses issues such as susceptibility to cracking, brittleness, and poor volumetric stability, which hinder its development and practical use in engineering applications. This study aimed to enhance the properties of the MgO-SiO2-H2O system by incorporating glass fiber as a reinforcing material. The mechanical properties, shrinkage properties, and properties during accelerated aging were tested at different content levels of glass fiber. Additionally, the reaction mechanism and microscopic morphology were characterized using microscopic testing methods. The results revealed that the addition of glass fiber improved the mechanical properties of the MgO-SiO2-H2O system; meanwhile, with an increase in fiber content, the mechanical properties showed an initial increase followed by a decreasing trend. With a glass fiber content of 0.6%, the system exhibited a flexural strength of 7.9 MPa at 28 d, a compressive strength of 42.5 MPa at 28 d, and a 27.2% increase in splitting tensile strength compared to the control group. At a fiber content of 0.9%, the flexural toughness steadily increased, reaching a maximum value of 2.238 N·m, which is 5.41 times greater than that of the control group. Moreover, the incorporation of glass fiber effectively inhibited the shrinkage of the MgO-SiO2-H2O system. Accelerated aging experiments confirmed that the glass fiber in the MgO-SiO2-H2O system did not undergo significant deterioration or corrosion, thereby maintaining long-term stability. These findings have important theoretical and practical significance for the application and development of the MgO-SiO2-H2O system.

Adsorption of Basic Yellow 28 and Basic Blue 3 Dyes from Aqueous Solution Using Silybum Marianum Stem as a Low-Cost Adsorbent

In the present study, the ability of an adsorbent (SLM Stem) obtained from the stem of the Silybum Marianum plant to treat wastewater containing the cationic dyes basic blue 3 (BB3) and basic yellow 28 (BY28) from aqueous solutions was investigated using a batch method. Then, the SLM Stem (SLM Stem-Natural) adsorbent was carbonized at different temperatures (200-900 °C) and the removal capacity of the products obtained for both dyes was examined again. The investigation continued with the product carbonized at 800 °C (SLM Stem-800 °C), the adsorbent with the highest removal capacity. The dyestuff removal studies were continued with the SLM Stem-Natural and SLM Stem-800 °C adsorbents because they had the highest removal values. The surface properties of these two adsorbents were investigated using IR, SEM, and XRD measurements. It was determined that the SLM Stem-Natural has mainly non-porous material, and the SLM Stem-800 °C has a microporous structure. The optimal values for various parameters, including adsorbent amount, initial dye solution concentration, contact time, temperature, pH, and agitation speed, were investigated for BY28 dye and were 0.05 g, 15 mg/L, 30 min, 40 °C, pH 6 and 100 rpm when SLM Stem-Natural adsorbent was used and, 0.15 g, 30 mg/L, 30 min, 40 °C, pH 10, and 150 rpm when SLM Stem-800 °C adsorbent was used. For BB3 dye, optimal parameter values of 0.20 g, 10 mg/L, 30 min, 25 °C, pH 7, and 100 rpm were obtained when SLM Stem-Natural adsorbent was used and 0.15 g, 15 mg/L, 40 min, 40 °C, pH 10, and 100 rpm when SLM Stem-800 °C adsorbent was used. The Langmuir isotherm described the adsorption process best, with a value of r2 = 0.9987. When SLM Stem-800 °C adsorbent was used for BY28 dye at 25 °C, the highest qm value in the Langmuir isotherm was 271.73 mg/g. When the study was repeated with actual water samples under optimum conditions, the highest removal for the BY28 dye was 99.9% in tap water with the SLM Stem-800 °C adsorbent. Furthermore, the reuse study showed the adsorbent's efficiency even after three repetitions.

Utilization of Waste Biomaterial as an Efficient and Eco-Friendly Adsorbent for Solid-Phase Extraction of Pantoprazole Contaminants in Wastewater

The objective of this analysis is to establish the potential of biodegradable agro-industrial waste materials as biosorbents in the solid-phase extraction (SPE) technique for sample preparation. In this regard, waste coffee husk (CH) powder was collected, washed, treated chemically, characterized, and applied as an SPE adsorbent to extract pantoprazole from the wastewater samples. Sample detection was accomplished using the UPLC-MS/MS system. The positive mode of electrospray ionization was exploited for the ionization of the sample, and quantification of the target analyte was performed by the multiple reaction monitoring modes. The precursor to product ion transition of 384.02→1380.05 and 384.02→200.05 was used as qualifiers and quantifiers, respectively. Optimization of the particle size, adsorbent dose, and contact time were evaluated to select the best combination of features. The efficiency and regeneration capability of the CH were compared with respect to a commercially available silica-based C18 SPE adsorbent, and it was found that CH possessed comparable (~50%) extraction, as well as regeneration capacity (~95%). The developed biosorbent was applied in a wastewater sample spiked with the target analyte and recovery studies were performed, which found a range of 93.0 to 102.0% with a %RSD of 3.72 to 12.7%. Thus, CH can be exploited as a ‘greener’ replacement for the commercially available adsorbents for the extraction/retention of active pharmaceutical ingredients present in water/wastewater samples.

Visible Light Active Magnesium Silicate–Graphitic Carbon Nitride Nanocomposites for Methylene Blue Degradation and Pb2+ Adsorption

Magnesium silicate nanosheets (MgSiNS) and graphitic carbon nitride (g-C3N4) nanocomposites were produced by varying different weight percentages of g-C3N4. The obtained nanocomposites were characterized by various techniques such as X-Ray diffraction (XRD), Fourier transformed infrared spectroscopy (FT-IR), diffuse reflectance UV–vis spectroscopy (DR UV–vis), N2-physisorption, transmission electron microscopy (TEM), and X-ray photon spectroscopy (XPS). The photocatalytic activities of the nanocomposites were measured using visible light irradiation to degrade methylene blue (MB) and Pb2+ adsorption in aqueous solution. The ideal physicochemical properties such as porosity, band gap energy, and functional groups in the MgSiNS-GN20 composite (80% MgSiNS and 20 wt % of g-C3N4) offered high Pb2+ adsorption (0.005 mol/g) and excellent MB degradation efficiency (approximately 93%) at pH 7 within 200 min compared to other composites. In addition, the influences of different reaction parameters such as the effect of pH, the load catalyst, and the concentration of MB and Pb+2 ions were examined. The obtained results indicate that inexpensive and eco-friendly MgSiNS and g-C3N4 composites could be recycled several times, hence representing a promising material to purify water from both organic and inorganic contaminants.

Poly(lactic acid)-poly(ethylene glycol)/Magnesium Silicate Membrane for Methylene Blue Removal: Adsorption Behavior, Mechanism, Ionic Strength and Reusability Studies

In this work, the effect of magnesium silicate (MgSiO3) as a filler on poly(lactic acid)-poly(ethylene glycol) (PLA-PEG) membrane was investigated towards the enhancement of adsorption capacity for removal of cationic dye. The preparation and fabrication of membranes were performed through copolymerization and phase inversion techniques. Analysis of functional groups, tensile strength, morphology and surface wettability were employed in the characterization of the membranes. After the addition of MgSiO3, it was found that the PLA-PEG/MgSiO3 membrane presented a higher hydrophilic property with improved mechanical strength. Next, the adsorption of methylene blue (MB) was optimized using response surface methodology (RSM) with the parameters mass of membrane and initial concentration of MB solution. The effects of pH and ionic strength were also examined to determine the mechanism involved during adsorption processes, which later were found to be electrostatic interaction and ion-exchange mechanism. From the isotherms and kinetics studies, the PLA-PEG/MgSiO3 membrane was well fitted by the Freundlich model and pseudo second order model, respectively. This membrane also demonstrated reusable character of up to six cycles.

Porous ZnCl2-Activated Carbon from Shaddock Peel: Methylene Blue Adsorption Behavior

It is of great interest and importance to resource utilization of waste biomass to produce porous carbon for environmental treatments. Pore structure and properties of the obtained carbon mainly relate to carbonization conditions and biomass types. In this work, a series of porous, biomass-activated carbons (AC) were prepared using shaddock peel, with ZnCl2 as a pore-forming agent. The effect of carbonization temperature and the mass ratio between ZnCl2 and shaddock peel were thoroughly investigated. The material composition, surface chemical properties, and surface structures of samples were carefully characterized. The specific surface area and adsorption capacity to methylene blue (MB) of adsorbents were changed with the carbonization temperature and the mass ratios between ZnCl2 and shaddock peel; when the temperature was at 1000 °C and the mass ratio was equal to 2:1, the resulting adsorbent had the largest specific surface area of 2398.74 m2/g and average pore size of 3.04 nm, which showed the highest adsorption capacity to MB to be 869.57 mg/g. The adsorption processes of biomass AC adsorbent matched the pseudo-second-order kinetic model and Langmuir isotherm model. This efficient and environmentally friendly biomass AC adsorbent from shaddock peel, activated by ZnCl2, is a promising candidate for the treatment of water pollution.

Activated Graphene Oxide-Calcium Alginate Beads for Adsorption of Methylene Blue and Pharmaceuticals

The remarkable adsorption capacity of graphene-derived materials has prompted their examination in composite materials suitable for deployment in treatment of contaminated waters. In this study, crosslinked calcium alginate–graphene oxide beads were prepared and activated by exposure to pH 4 by using 0.1M HCl. The activated beads were investigated as novel adsorbents for the removal of organic pollutants (methylene blue dye and the pharmaceuticals famotidine and diclofenac) with a range of physicochemical properties. The effects of initial pollutant concentration, temperature, pH, and adsorbent dose were investigated, and kinetic models were examined for fit to the data. The maximum adsorption capacities q_max obtained were 1334, 35.50 and 36.35 mg g⁻¹ for the uptake of methylene blue, famotidine and diclofenac, respectively. The equilibrium adsorption had an alignment with Langmuir isotherms, while the kinetics were most accurately modelled using pseudo- first-order and second order models according to the regression analysis. Thermodynamic parameters such as ΔG°, ΔH° and ΔS° were calculated and the adsorption process was determined to be exothermic and spontaneous.

A facile synthesis of one-dimensional hierarchical magnetic metal silicate microtubes with enhanced adsorption performance

One-dimensional (1D) hierarchical magnetic hollow micro/nanotubes have attracted special attention in the field of adsorption owing to their high surface area, easy separation and short mass diffusion. Here, we report a facile approach for synthesizing one-dimensional hierarchical magnetic metal silicate microtubes through an extended Stöber method, carbonization treatment and subsequent hydrothermal reaction with metal ions in an alkaline solution. The unique 1D hierarchical magnetic microtubes have a large surface area, good structural stability and high magnetic response. Benefiting from these advantages, the resultant microtubes display excellent performance as good adsorbents for bovine hemoglobin (BHb) and methylene blue (MB). Furthermore, this strategy can also be applied to prepare other 1D hierarchical magnetic metal silicate composites.

Ethylene glycol-assisted fabrication and superb adsorption capacity of hierarchical porous flower-like magnesium oxide microspheres for phosphate

Hierarchical porous flower-like MgO microspheres were fabricated via an ethylene glycol-assisted route under mild conditions and exhibited an outstanding maximum adsorption capacity of 574.71 mg g⁻¹ for phosphate.