Triptycene-based micorporous polymer is functionalized with CO sub(2)-philic tetrazole moieties via ZnCl sub(2)-catalyzed post-polymerization. Gas adsorption experiments indicate that it possesses ...high CO sub(2) uptake capacity, reaching 134 cm super(3) g super(-1) (26.5 wt%) at 1.0 bar and 273 K, along with high selectivity towards CO sub(2) over N sub(2) and CH sub(4). The porous polymeric networks present the promising potentials as efficient adsorbents in clean energy applications. Triptycene-based micorporous polymer is functionalized with CO sub(2)-philic tetrazole moieties via ZnCl sub(2)-catalyzed post-polymerization, which shows high CO sub(2) uptake capacity, reaching 134 cm super(3) g super(-1) (26.5 wt%) at 1.0 bar and 273 K.
A novel kind of solid amine-containing fibrous adsorbent (PP-GMA-TETA) was prepared through irradiation grafting copolymerization with glycidyl methacrylate (GMA) onto polypropylene (PP) fiber, ...followed by reacting with triethylenetetramine (TETA) to introduce primary and secondary amine groups on its surface. The effects of the reaction conditions, such as the TETA concentration, temperature, and reaction time on amination degree of PP-GMA-TETA, were investigated. Adsorption capacity of PP-GMA-TETA with 77.7% amination degree could reach 4.72 mmol/g. After adsorption, the spent fiber could be completely regenerated at 100 °C by steam for 20 min and its adsorption behavior kept almost constant within six recycles. The comparison of adsorption capacities of amine fibers aminated with various aminating agents also demonstrated that fibers with higher content of primary amine would obtain faster adsorption rates and higher adsorption capacities.
SiO sub(2)iO core-shell nanoparticles with variable NiO shell thickness have been prepared via homogeneous precipitation. The as prepared and calcined core-shell nanoparticles have been characterized ...using powder X-ray diffraction, thermal gravimetric analysis, FT-IR spectroscopy, scanning electron microscopy, transmission electron microscopy, and surface area measurements. The shell thickness and the particle size of NiO in the core-shell nanoparticles have been controlled using different concentrations of the nickel salt. The NiO shell thickness, as observed by the TEM, varies from about 46 to 144 nm. The SiO sub(2)iO core-shell nanoparticles show higher remanent magnetization, saturation magnetization, and lower coercivity compared to pure NiO nanoparticles. The SiO sub(2)iO core-shell nanoparticles have been tested as adsorbents for the removal of methylene blue from an aqueous solution and the core-shell nanoparticles possess good adsorption efficiency for the cationic dye compared to pure NiO and SiO sub(2).
The removal of contaminants from wastewaters is a major challenge in the field of water pollution. Among numerous techniques available for contaminant removal, adsorption using solid materials, named ...adsorbents, is a simple, useful and effective process. The adsorbent matter can be mineral, organic or biological. Activated carbon is the preferred, conventional material at the industrial scale. Activated carbon is extensively used not only for removing pollutants from wastewater streams, but also for adsorbing contaminants from drinking water sources, e.g., groundwater, rivers, lakes and reservoirs. However, the widespread use of activated carbon is restricted due to a high cost. In the last three decades, numerous approaches using non-conventional adsorbents have been studied for the development of cheaper and more effective adsorbents to eliminate pollutants at trace levels. This review gives an overview of liquid–solid adsorption processes using conventional and non-conventional adsorbents for pollutant removal. The manuscript outlines the principles of adsorption and proposes a classification for adsorbent materials. Finally, the various mechanisms involved in the adsorption phenomena are discussed.
Using expanded WangaLandau simulations, we study the adsorption of hydrogen in a series of covalent organic frameworks (COF-102, COF-105 and COF-108). In the present implementation, this new method, ...based on the WangaLandau sampling, allows for a uniform sampling of the number of molecules adsorbed in the COFs. We show that this method leads to a highly accurate estimate of the grand canonical partition function for the system and gives excellent results for the adsorption isotherms of , both at and , when compared to prior simulation work and experiments. Moreover, various thermodynamic properties of adsorption, including entropy, Gibbs free energy and Helmohltz free energy, as well as the desorption properties are calculated, providing insight into the adsorption phenomenon. We finally propose a ranking for the performance of the three COFs for adsorption, based on the isothermal work required to regenerate the adsorbent , and find the following order for applications at ambient temperature.
A noticeable interest and steady rise in research studies reporting the design and assessment of smart adsorbents for sequestering aqueous metal ions and xenobiotics has occurred in the last decade. ...This motivates compiling and reviewing the characteristics, potentials, and performances of this new adsorbent generation's metal ion and xenobiotics sequestration. Herein, stimuli‐responsive adsorbents that respond to its media (as internal triggers; e.g., pH and temperature) or external triggers (e.g., magnetic field and light) are highlighted. Readers are then introduced to selective adsorbents that selectively capture materials of interest. This is followed by a discussion of self‐healing and self‐cleaning adsorbents. Finally, the review ends with research gaps in material designs.
Smart adsorbents respond to internal (e.g. pH, temperature) and/or external (e.g. magnetic field, light) triggers, and deliver selective adsorption behavior. In this review, the characteristics and adsorption performances of smart adsorbents in taking up aqueous environmental micropollutants are discussed. The self‐healing and self‐cleaning properties of specific smart adsorbents are also discussed in context of their reusability.
Dye effluents released from numerous dye-utilizing industries are harmful towards the environment and living things. Consequently, existence of dye effluent in environmental water bodies is becoming ...a growing concern to environmentalists and civilians. A long term sustainable and efficient dye effluent treatment method should be established to eliminate this issue. Dye wastewater should be treated first before release to minimize its negative impacts towards the environment and living things. However, due to lack of information on efficient dye removal methods, it is difficult to decide on a single technique that resolves the prevailing dye effluent issue. Therefore, this paper reviews existing research papers on various biological, chemical and physical dye removal methods to find its efficiency through percentage of dye removal. Although there are numerous existing tried and tested methods to accomplish dye removal, most of them have a common disadvantage which is the generation of secondary pollution to the environment. This paper highlights enzyme degradation (biological) and adsorption (physical) dye removal as these are known as one of the most efficient dye removal techniques these days. This paper also suggests the usage of a combined adsorbent as it is envisioned that this technique has better efficiency and is able to remove dyes at a faster rate.
Micropollutants, also called emerging contaminants, consist of an extensive group of synthetic and natural substances, including pharmaceuticals, personal care products, steroid hormones, and ...agrochemicals. Currently, the monitoring of residual pharmaceuticals in the environment has been highlighted due to the fact that many of these substances are found in wastewater treatment plants effluents and surface waters, in concentrations ranging from ng L−1 to μg L−1. Most of these compounds are discharged into the environment continuously through domestic sewage treatment systems. In the present work, it is presented an overview of water pollution by these pollutants, as well as a review of the recent literature about the use of low-cost adsorbents for the removal of the main pharmaceuticals found in surface water, focusing on municipal and agroindustrial wastes as precursors. It was possible to observe several examples of high adsorption capacities of these compounds with such materials, however other aspects must be considered in order to evaluate the real applicability in water and wastewater treatment, such as competition, recyclability and production cost.
•Pharmaceuticals have been found in surface water in ng L−1 to μg L−1.•Pharmaceuticals can be persistent in the environment.•Adsorption is effective in removing organic and inorganic pollutants from water.•Adsorption has been investigated for the removal of several pharmaceuticals.•Municipal and agro-industrial wastes can be used as precursors of adsorbents.
The aim of this study was to evaluate the effects of different anti-mycotoxin feed additives on the concentration of mycotoxins in milk, urine, and blood plasma of dairy cows fed artificially ...multi-mycotoxin-contaminated diets. Secondarily, performance, total-tract apparent digestibility of nutrients, and blood parameters were evaluated. Twelve multiparous cows (165 ± 45 d in milk, 557 ± 49 kg body weight, and 32.1 ± 4.57 kg/d milk yield at the start of the experiment) were blocked according to parity, milk yield, and days in milk and used in a 4 × 4 Latin square design experiment with 21-d periods, where the last 7 d were used for sampling and data analysis. Treatments were: 1) Mycotoxin group (MTX), basal diet (BD) without anti-mycotoxin feed additives; 2) Hydrated sodium calcium aluminosilicate (HSCA), HSCA added to the BD at 25g/cow/d; 3) Mycotoxin deactivator 15 (MD15), MD (Mycofix® Plus, dsm-firmenich) added to the BD at 15 g/cow/d; and 4) Mycotoxin deactivator 30 (MD30), MD added to the BD at 30 g/cow/d. Cows from all treatments were challenged with a blend of mycotoxins containing 404 μg aflatoxins B1 (AFB1), 5,025 μg deoxynivalenol (DON), 8,046 μg fumonisins (FUM), 195 μg T2 toxin (T2), and 2,034 μg of zearalenone (ZEN) added daily to the BD during the last 7 d of each period. Neither performance (milk yield and composition) nor nutrient digestibility was affected by treatments. All additives reduced aflatoxin M1 (AFM1) concentration in milk, whereas MD15 and MD30 group had lower excretion of AFM1 in milk than HSCA. DON, FUM, T2, or ZEN were not detected in milk of MD15 and MD30. Concentrations in milk of DON, FUM, T2, and ZEN were similar between MTX and HSCA. Except for AFM1, none of the analyzed mycotoxins were detected in urine of MD30 group. Comparing HSCA to MD treatments, the concentration of AFM1 was greater for HSCA, whereas MD30 was more efficient at reducing AFM1 in urine than MD15. AFM1, DON, FUM, and ZEN were not detected in the plasma of cows fed MD30, and DON was also not detected in MD15 group. Plasma concentration of FUM was lower for MD15, similar plasma FUM concentration was reported for HSCA and MTX. Plasma concentration of ZEN was lower for MD15 than MTX and HSCA. Serum concentrations of haptoglobin and hepatic enzymes were not affected by treatments. Blood concentration of sodium was lower in HSCA compared with MD15 and MD30 groups. In conclusion, the mycotoxin deactivator proved to be effective in reducing the secretion of mycotoxins in milk, urine, and blood plasma, regardless of the dosage. This reduction was achieved without adverse effects on milk production or total-tract digestibility in cows fed multi-mycotoxin-contaminated diets over a short-term period. Greater reductions in mycotoxin secretion were observed with full dose of MD.
Alternative to current liquid amine technologies for post‐combustion CO2 capture, new technologies such as adsorbent‐based processes are developed, wherein material lifetime and degradation is ...important. Herein a robust method to determine degradation rates in a laboratory setup is developed, which was validated with a continuous multi‐staged fluidized bed pilot plant designed to capture 1 ton CO2 per day. An amine functionalized polystyrene adsorbent showed very good agreement between the experimental 1000‐hour laboratory degradation rates and 2200 hours of degradation in a pilot plant. This validates how laboratory experiments can be extrapolated for sorbent screening and for scale‐up. Resulting, the oxidative degradation in the desorber at high temperatures (120 °C) and low O2 concentrations (150 ppmv) is 3 times higher compared to the adsorber at low temperatures and high O2 (56 °C, 7 vol %). Laboratory degradation experiments can hence be used to further optimize process operations to limit degradation or screen for potential new adsorbents.
A robust method to determine degradation rates of an amine functionalized polystyrene adsorbent in a laboratory setup is developed and validated with a continuous multi‐staged fluidized bed pilot plant. The very good agreement between experimental 1000‐hour laboratory and 2200‐hour pilot degradation showcases how small scale experiments can be extrapolated for scale‐up and adsorbent screening.
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