Adsorption of aspirin on the macropore resin with six functional group sites: Multiple functional group sites in macropore resin versus the micropore filling in hypercrosslinked resin

Remediation of water tainted with noxious aspirin and fluoride ion using UiO-66-NH2 loaded peanut shell

One green adsorbent, UiO-66-NH2 modified peanut shell (c-PS-MOF), was prepared in a green synthetic route for improving the capture level of aspirin (ASP) and fluoride ion (F-). The adsorption properties of c-PS-MOF were evaluated by batch experiments and its physicochemical properties were explored by various characterization methods. The results showed that c-PS-MOF exhibited a wide range of pH applications (ASP: 2-10; F-: 3-12) and high salt resistance in the capturing processes of ASP and F-. The unit adsorption capacity of c-PS-MOF was as high as 84.7 mg·g-1 for ASP as pH = 3 and 11.2 mg·g-1 for F- under pH = 6 at 303 K from Langmuir model, respectively. When the solid-liquid ratio was 2 g·L-1, the content of ASP (C0 = 100 mg·L-1) and F- (C0 = 20 mg·L-1) in solution can be reduced to 0.48 mg·L-1 and 1.05 mg·L-1 separately. The recycling of c-PS-MOF can be realized with 5 mmol·L-1 NaOH as eluent. Analysis of simulated water samples showed that c-PS-MOF could be used to remove ASP and F- from actual water. The c-PS-MOF is promising to bind ASP and F- from rivers, lakes, etc.

Effects of Pore Parameters and Functional Groups in Coal on CO2/CH4 Adsorption

The mechanisms of CO₂/CH₄ adsorption in coal are the theoretical foundation for CO₂ sequestration in coal seams targeted for enhanced coalbed methane recovery. Herein, by changing the model (low rank coal: WMC, middle rank coal: XM and high rank coal: CZ) with plenty of side aliphatic chains and functional groups established in the literature, the influence and mechanism of pore parameters and functional groups(-CH₃, -OH, -C₂O, -C=O) on the adsorption of CO₂ and CH₄ in different rank coals are systematically studied. Using the Connolly surface algorithm to calculate the pore volume (V ^F) and the specific surface area (S ^SA) of coal with different functional groups, it can be seen that the influence of the functional group change on the pore structure is related to the coal rank. Changing the various functional groups in the original coal structure to a unified functional group (-CH₃, -OH, -C₂O, or -C=O) will increase the accessible pore volume (V ^F) and the specific surface area (S ^SA), except in low-rank and middle-rank coal, where the ordered arrangement of -C=O will decrease V ^F and S ^SA. The adsorption capacities of different pore parameters and functional groups were calculated by Grand Canonical Monte Carlo simulation and density functional theory. On pure adsorption, the pore parameters exert greater influence than the functional groups. By comparing the adsorption energy of the original pore structure containing functional groups and that of modified pores without functional groups, the contributions of the pore structure and original functional groups on CO₂/CH₄ adsorption are 71 and 29% and 83 and 17%, respectively. Small-diameter pores and -C₂O have a strong adsorption capacity. In terms of competitive adsorption, the -C=O functional groups and pore diameters ranging from 1.0 to 2.0 nm can significantly enhance the selectivity of CO₂ over CH₄. The CH₄ and CO₂ adsorption does not occur via rigorous monolayer adsorption; multilayer adsorption can occur for CH₄ and CO₂ with pore diameters of 1.0-2.0 and 1.0-2.2 nm, respectively, thus causing micropore filling. These quantitative results establish a foundation for the development of adsorption theory for CO₂/CH₄ in coal.

DETA impregnated attapulgite hybrid ZIF-8 composite as an adsorbent for the adsorption of aspirin and ibuprofen in aqueous solution

The diethylenetriamine (DETA) impregnated modified attapulgite hybrid ZIF-8 composite is a new type of amine impregnated hybrid MOF adsorbent, which has an excellent ability to remove aspirin and ibuprofen from aqueous solution.

Performance Evaluation of Biodiesel Produced from Waste Tire Pyrolytic Oil as a Lubricant Additive in Oil Drilling Systems

This study investigates the performance of biodiesel produced from distilled waste tire pyrolytic oil through transesterification as a lubricant additive for aqueous drilling fluid systems. Aqueous-based drilling fluids have a high coefficient of friction as compared to oil-based drilling fluids. The inclusion of a biodiesel additive was for smooth application/operation. The friction-reducing physicochemical properties of the additive were analyzed and compared with the guidelinesof the United States specification (ASTM Standard) and the European specification (EN Standard). The chemical structure of the produced biodiesel was analyzed using gas chromatography–mass spectrometry (GC-MS). The results show that the distilled waste tire pyrolytic oil contains aliphatic, naphthenic, and aromatic hydrocarbons. The free fatty acid value reduced from 5.6% (for pyrolytic oil) to 0.64% after the transesterification process. A saponification value of 203.36 mg/g was recorded for the pyrolytic oil, and this value was also reduced to 197.35 mg/g after the transesterification process. The kinematic viscosity was reduced from 11.2 to 5.3 mm2/s for the obtained biodiesel, and this value is within the ASTM D6751 and EN 14214 standard values (1.9 to 6 and 3.5 to 5 mm2/s, respectively). The cetane number (47.75) was obtained for the biodiesel, and this is within the minimum range stipulated in ASTM D6751 guidelines. The produced biodiesel’s chemical structure analysis using GC-MS shows that it comprises of decanoic acid methyl ester and methyl ester. Furthermore, comparative analysis of the quantified friction-reducing physicochemical properties of the additive shows that the biodiesel produced from the distilled pyrolytic oil is a suitable additive for the improved lubrication of the friction-prone metallic parts of drill bits when water-based drilling fluids are employed for drilling oil and gas wells.