Application Of Adsorption Technology Research Articles

MIL-161 Metal-Organic Framework for Efficient Au(III) Recovery from Secondary Resources: Performance, Mechanism, and DFT Calculations.

The recovery of precious metals from secondary resources is significant economically and environmentally. However, their separation is still challenging because they often occur in complex metal ion mixtures. The poor selectivity of adsorbents for gold in complicated solutions prevents further application of adsorption technology. In this study, a Zr-based MOF adsorbent, MIL-161, was synthesized using s-tetrazine dicarboxylic acid (H2STz) as an organic ligand. MIL-161 demonstrated a high adsorption capacity of up to 446.49 mg/g and outstanding selectivity for gold(III) in a simulated electronic waste solution as a result of the presence of sulfur- and nitrogen-containing groups. In addition, the MIL-161 adsorbents were characterized using Fourier transform infrared (FT-IR), field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TG), Brunner-Emment-Teller (BET), and X-ray photoelectron spectroscopy (XPS). Additionally, the adsorption kinetics, isotherms, and thermodynamics of the MOF adsorbents were also thoroughly examined. More importantly, the experimental results and DFT calculations indicate that chelation and electrostatic interactions are the main adsorption mechanisms.

Optimization of Binary Adsorption of Metronidazole and Sulfamethoxazole in Aqueous Solution Supported with DFT Calculations

Sulfamethoxazole [SMX] and metronidazole [MNZ] are emergent pollutants commonly found in surface water and wastewater, which can cause public health and environmental issues even at trace levels. An efficient alternative for their removal is the application of adsorption technology. The present work evaluated single and binary adsorption processes using granular activated carbon (CAG F400) for SMX and MNZ in an aqueous solution. The binary adsorption process was studied using a Box–Behnken experimental design (RSD), and the results were statistically tested using an analysis of variance. Density functional theory (DFT) modeling was employed to characterize the interactions between the antibiotics and the CAG F400 surface. For the individual adsorption process, adsorption capacities (qe) of 1.61 mmol g−1 for SMX and 1.10 mmol g−1 for MNZ were obtained. The adsorption isotherm model that best fit experimental data was the Radke–Prausnitz isotherm model. The adsorption mechanism occurs through electrostatic and π-π dispersive interactions. For the binary adsorption process, the total binary adsorption capacity achieved was 1.13 mmol g−1, evidencing competitive adsorption. The significant factors that determine the removal of SMX and MNZ from a binary solution were the solution pH and the initial concentration of antibiotics. From DFT studies, it was found that SMX adsorption on CAG F400 was favored with adsorption energy (Eads) of −10.36 kcal mol−1. Finally, the binary adsorption results corroborated that the adsorption process was favorable for both molecules.

Global trends and prospects in the removal of pharmaceuticals and personal care products: A bibliometric analysis

This study examined 9066 publications on the removal of pharmaceuticals and personal care products (PPCPs) published between 1998 and 2019 through a bibliometric approach based on the SCIE and SSCI databases. The overall research distribution of PPCPs, characteristics of pollutants, water pollution types, and up-to-date treatment technologies were revealed. The results showed that the number of articles relating to the removal of PPCPs increased significantly, with China contributing the most, followed by the United States and Spain. Water Research is the most productive journal, and the h-index is the highest (110). Five clusters were identified from the keyword network, namely polluted water types, biological treatment, adsorption, advanced oxidation, and membrane treatment technology. Through the elaboration of clustering and its relationship, it was found that research and development of technologies were the main concerns, and the application of adsorption technology was the most extensive. The most commonly used adsorbent is carbon material, while nanomaterial and biomaterial adsorbent are promising. These findings help to identify the global trend of PPCPs removal and provide valuable references for further research in this area.

Improvement of Malang Tahu Quality Using Sweet Potato Natural Dyes by Adsorption Technology

Tahu is a popular culinary product in Malang town. This product is produced from soyabean and rich of protein. Besides, tahu is also rich of water, so that surface of tahu tends to polar. Colorization of tahu by extract of yellow and sweet potatoes is interesting because both sweet potatoes contains different polarity molecular dyes, i.e. polar anthocyanin in the purple sweet potato but non-polar beta carotene in the yellow sweet potato. In this paper, changing of tahu’s color after colorization by extract of both sweet potatoes was observed at different times of adsorption process (2, 4, 6 h), different compositions of the sweet potato and water (100g/1L and 300g/1L), and effect of palm oil addition (250 mL oil/1L water). Result of observation showed that the higher time of adsorption process, the higher ratio of the sweet potato weight and water volume, the darker color of the colorized tahu. Addition of the palm oil just improved extraction of β - carotene from the yellow sweet potato but did not improve the adsorption of the dyes on the tahu surface. Results of this study are used for supporting program of community service DPP SPP 2020 of Inorganic lecturers, as application of adsorption technology using tahu food as adsorbent and application of intermolecular force theory as part of Inorganic Chemistry I course.

Highly efficient and selective removal of Cr(VI) by covalent organic frameworks: Structure, performance and mechanism

In consideration of increasingly serious environmental issues, and concern for the environmental impact by heavy metals, materials have been developing to act as adsorbents with high capacity and selectivity for metal ions in the environment. Covalent organic frameworks (COFs) are potential materials for addressing these environmental challenges as their molecular skeletons can be aimed at particular application by predesigned affine functional groups. Here, two COFs namely COF1 and COF2 with different hydroxyl group distributions were successfully synthesized from 1,3,5-triaminobenzene (TAB) and 2,3-dihydroxyterephthalaldehyde (2,3-Dha) or 2,5-dihydroxyterephthalaldehyde (2,5-Dha), respectively. COF2 exhibited a high adsorption capacity of 649.35 mg g−1 for Cr(VI) in water, performing better than COF1 and most of previously reported adsorbents. COF1, however, performed better than COF2 at a low Cr(VI) concentration (<20 mg L−1), while COF2 was more efficient at higher concentration due to the more available and homogenic sites provided by the para –OH functional group. Both COFs showed a good performance in removing Cr(VI) within a wide solution pH, and exhibited high selectivity for Cr(VI) in mixed ion solutions. According to FTIR and XPS spectra analysis, the synergism from electrostatic interaction and intramolecular hydrogen bond mainly devoted to the capture of Cr(VI) in acidic or slightly basic solution. Based on the aforementioned research, designing COFs with high selectivity and adsorption capacity for the targeted containments would be a tendency in the further application of adsorption technology.

Regeneration of PFOS loaded activated carbon by hot water and subsequent aeration enrichment of PFOS from eluent

Regeneration and reuse of spent activated carbon (AC) as well as recovery of the desorbed pollutants are challenging in the application of adsorption technology. In this study, the regeneration of perfluorooctanesulfonate (PFOS)-saturated coal-based granular AC by hot water and subsequent aeration method to enrich PFOS from eluent were investigated. The regeneration time, water temperature and solid-liquid ratio affected the regeneration efficiency of PFOS treated AC. PFOS was desorbed quickly from the AC within 30 min by hot water. High water temperature (92 °C) and low solid-liquid ratio (0.5) led to the highest desorption of 36.7% in one cycle (6 h). Over 90% PFOS on the spent AC was desorbed by 92 °C hot water with the solid-liquid ratio of 0.5 after six cycles. Subsequent experiments were conducted to enrich PFOS, and aeration of the regeneration eluent achieved the enrichment factors of 50.6–62.0 for PFOS at initial PFOS concentrations of 10–100 μg/L. The concentration of PFOS in the concentrated solution was 2.2 g/L following sequential sorption, regeneration and aeration treatments when the influent PFOS concentration was 2.7 μg/L.

Experimental and Numerical Analysis of the Influence of Thermal Control on Adsorption and Desorption Processes in Adsorbed Natural Gas Storage

Natural gas,the most environmentally friendly fossil fuel, can be stored in a vessel based on adsorption technology, designed for energy efficient storage of natural gas at relatively medium pressures (3‒4 MPa).The application of adsorption technology will reduce the energy consumption for gas compressing or gas liquefying compared to compressed and liquefied natural gas storage methods,also, it will lead to cost savings in compressing and cooling equipment. While charging/discharging of adsorbed natural gas (ANG) vessel, the latent heat of adsorption counteracts to adsorption/desorption process, as the result, thermal effect causes a reduction of vessel capacity. Therefore,the influence of thermal control on adsorption and desorption processes in adsorbed natural gas vessel was studied experimentally and numerically in this paper. The study focusing on the three dimensional heat exchange is important in order to understand the heat transfer phenomena and analyze influence of thermal control comprehensively. The temperature and adsorption uptake profiles in the vessel were demonstrated in the numerical simulation. Comparison of experimental and simulation results showed that deviation between experimental and numerical results was 0.1%.

吸附技术在铀分离富集过程中的应用研究

本文综述了吸附技术在铀的富集、分离过程中应用进展，对无机吸附材料、生物吸附材料和有机吸附材料对铀的吸附过程和机理进行了总结；在此基础上进一步指出了铀吸附技术的具体研究方向，为铀的分离富集技术的发展提供借鉴。 In this paper, the application of adsorption technology in the enrichment and separation of uranium is reviewed. The adsorption process and mechanism of the inorganic material, biological materials and organic material were summarized. On the basis of the review, the specific research direction of uranium adsorption technology is pointed out. The results could provide reference for the development of separation and enrichment of uranium.

The Separation and Purification of Gases Using Solid Adsorbents

Abstract This paper presents a bibliography of some of the published work concerning the adsorption of gases and vapors by solid materials. The papers considered all contain experimental data which are mainly adsorption equilibrium isotherm data, although some of the references include kinetic data. The references are grouped according to the gases adsorbed with a brief statement of the conditions under which the data were obtained. The aim is to provide a reference source for use in the design stage when considering applications of adsorption technology. The factors to be considered in the design of adsorption separation systems are considered and the areas identified where research and publication are required.