Mechanistic understanding of the adsorption of natural organic matter by heated aluminum oxide particles (HAOPs) via molecular dynamics simulation

Room temperature fabrication of magnetic covalent organic frameworks for efficient enrichment of parabens in water

A novel 4 + 2 covalent magnetic organic framework (COF) with core-shell structure was synthesized for the first time with N, N, N', N'-Tetrakis (4-aminophenyl)-1, 4- benzenediamine (TPDA) and 2, 6-Pyridinedicarboxaldehyde (PCBA) at room temperature. The synthesized magnetic TPDA-PCBA-COF has a large specific surface area and superparamagnetism, which makes it an ideal sorbent for trace analytes enrichment. To this end, we combined it with magnetic solid phase extraction (MSPE) to enrich trace parabens in environmental water. The parameters affecting the enrichment efficiency of magnetic solid phase extraction, such as the amount of Fe₃O₄@TPDA-PCBA-COF, extraction time, pH of samples, salt concentration, desorption solvent volume and desorption time, were optimized. A simple method for extraction and determination of parabens in water samples by MSPE combined with high performance liquid chromatography (HPLC) was established under optimized conditions. The validation results revealed that the linear ranges were at 1.0-5.0 × 10² ng mL^-1 with R value between 0.9915 and 0.9999, the spiked recoveries were in the range of 82.8% to 99.9% and RSDs were lower than 10%. The method was further applied to the determination of parabens in water samples, with recoveries in the range of 82.2% to 110.0% and RSDs ≤ 7.7%. These results suggest that the magnetic TPDA-PCBA-COF could be used as a promising adsorbent for efficient extraction and quantitation of parabens in environmental water samples.

Synthesis of heated aluminum oxide particles impregnated with Prussian blue for cesium and natural organic matter adsorption: Experimental and machine learning modeling

Heated aluminum oxide particles impregnated with Prussian blue (HAOPs-PB) are synthesized for the first time using different molar ratios of aluminum sulfate and PB to improve the adsorption of cesium (¹³³Cs⁺) and natural organic matter (NOM) from an aqueous solution. The Cs⁺ adsorption from various aqueous solutions, including surface, tap and deionized water by synthesized HAOPs-PB, is investigated. The influencing factors such as HAOPs-PB mixing ratio, pH and dosage are studied. In addition, pseudo 1st and 2nd order is tested for adsorption kinetics study. A machine learning model is developed using gene expression programming (GEP) to evaluate and optimize the adsorption process for Cs⁺ and NOM removal. Synthesized adsorbent showed maximum adsorption at a 1:1 M ratio of aluminum sulfate and PB in DI, tap, and surface water. The pseudo 2nd order kinetics model described the Cs ⁺ adsorption by HAOPs-PB more accurately that indicating physiochemical adsorption. Adsorption of Cs⁺ showed an increasing trend with higher HAOPs-PB concentration, while high pH also favored the adsorption. Maximum NOM adsorption is found at a higher HAOPs-PB dosage and a neutral pH value. Furthermore, the proposed GEP model shows outstanding performance for Cs⁺ adsorption modeling, whereas a modified-GEP model presents promising results for NOM adsorption prediction for testing dataset by learning the relationship between inputs and output with R² values of 0.9348 and 0.889, respectively.

A Review on the Morphology and Material Properties of the Gas Separation Membrane: Molecular Simulation

Gas membrane separation technology is widely applied in different industry processes because of its advantages relating to separation performance and economic efficiency. It is usually difficult and time consuming to determine the suitable membrane materials for specific industrial separation processes through traditional experimental research methods. Molecular simulation is widely used to investigate the microscopic morphology and macroscopic properties of materials, and it guides the improvement of membrane materials. This paper comprehensively reviews the molecular-level exploration of the dominant mechanism and influencing factors of gas membrane-based separation. The thermodynamics and kinetics of polymer membrane synthesis, the molecular interactions among the penetrated gases, the relationships between the membrane properties and the transport characteristics of different gases in the composite membrane are summarized and discussed. The limitations and perspectives of the molecular simulation method in the study of the gas membrane separation process are also presented to rationalize its potential and innovative applications. This review provides a more comprehensive reference for promoting the materials' design and engineering application of the gas separation membrane.