The adsorption behavior of 2,4-dichlorophenol (2,4-DCP) using phosphonium-based ionic liquid immobilized in polysulfone (PSF) capsules was systematically investigated to elucidate the underlying mechanisms and performance characteristics. The study focused on understanding how solution pH, temperature, and salinity influence the removal efficiency, as well as determining the kinetic and equilibrium pathways governing the process. Experimental results revealed that the optimal pH range for maximum 2,4-DCP adsorption was between 3.0 and 9.0. At lower pH values (below 3), protonation of the phenolic hydroxyl group enhances hydrogen bonding with the phosphonium cation, favoring adsorption. Conversely, at high pH (above 10), deprotonation leads to the formation of negatively charged 2,4-DCP anions, which experience electrostatic repulsion from the ionic liquid phase, reducing adsorption capacity. Despite this, the system maintained a relatively stable performance across the tested pH range, indicating resilience to moderate variations commonly found in industrial effluents. Temperature had no significant effect on adsorption capacity within the range of 25–70 °C, suggesting that the process is thermodynamically favorable and likely exothermic, consistent with physisorption-dominated interactions. This thermal stability further supports the feasibility of applying the capsules in diverse environmental conditions without requiring energy-intensive temperature control.GDAP1L1 Antibody Purity
Kinetic analysis demonstrated that the adsorption process followed a pseudo-second-order model, with a correlation coefficient (R²) of 0.GALE Antibody In Vivo 9877, confirming that the rate-limiting step involves chemical interaction between 2,4-DCP and the immobilized ionic liquid. The half-adsorption time (t₁/₂) was calculated to be approximately 16.2 minutes, indicating rapid uptake kinetics. Weber-Morris model fitting confirmed that intraparticle diffusion governs the mass transfer mechanism, as evidenced by a linear relationship between qt and t⁰·⁵, with a slope corresponding to a diffusion coefficient of 4.027 × 10⁻⁵ cm²/min. The initial rapid uptake phase reflects fast external diffusion, while the gradual plateau indicates slower internal diffusion into the capsule’s porous structure. Additionally, the presence of a non-zero intercept in the Weber-Morris plot suggests the existence of a boundary layer resistance, which may be attributed to the slow transport of 2,4-DCP molecules through the polymer matrix before reaching active sites. In terms of salt tolerance, increasing NaCl concentration up to 1000 mg/L did not significantly impair adsorption performance, demonstrating the robustness of the system in saline environments—common in industrial wastewater. This insensitivity to ionic strength is advantageous over conventional adsorbents, where competitive ion effects often reduce efficiency.PMID:34579948
Equilibrium studies were conducted using Langmuir, Freundlich, and Redlich-Peterson isotherm models. Among them, the Redlich-Peterson model provided the best fit (R² = 0.9782), with a β value of 0.821, close to 1.0, indicating a near-ideal monolayer adsorption mechanism. The Langmuir model yielded a maximum adsorption capacity (qmax) of 404.50 mg/g, one of the highest reported for similar systems. The separation factor (RL = 0.0231) confirmed favorable adsorption conditions. Furthermore, the Freundlich model parameter n = 3.037 > 1 implies heterogeneous surface adsorption, consistent with physisorption via van der Waals forces and dipole interactions. The absence of a significant contribution from chemisorption was supported by the low activation energy derived from kinetic data. Overall, the combination of high capacity, rapid kinetics, excellent pH and salinity tolerance, and predictable mechanistic behavior establishes these PSF capsules as a highly effective and reliable platform for removing recalcitrant organic pollutants like 2,4-DCP from aqueous solutions. Their compatibility with fixed-bed reactors and potential for regeneration make them a promising candidate for scalable water treatment technologies targeting persistent phenolic contaminants.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com