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Ferrandon, O., H. Bouabane, and M. Mazet. "Contribution à l'étude de la validité de différents modèles, utilisés lors de l'adsorption de solutés sur charbon actif." Revue des sciences de l'eau 8, no. 2 (April 12, 2005): 183–200. http://dx.doi.org/10.7202/705218ar.
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Les résultats de l'adsorption sur charbon actif en poudre de solutions aqueuses de différents composés organiques: phénol, aniline, nitrobenzène, acide salicylique, nitro-4 phénol, méthyl-2 dinitro-4,6 phénol, phénylalanine et tyrosine ont été traités à l'aide des équations de Langmuir, Elovich, Freundlich, Temkin, Fowler-Guggenheim, Hill et De Boer, Kiselev afin de déterminer divers paramètres d'équilibre: la capacité maximum d'adsorption, l'énergie d'adsorption, l'énergie d'interaction, les constantes d'équilibre adsorbat-adsorbant et les interactions (éventuelles) entre les molécules adsorbées. La relation de Temkin (3=RTt~Q In KoC permet de déterminer la variation de l'énergie d'adsorption ~Q et la constante Ko de l'équilibre (~3 est le degré de re- couvrement du charbon par le soluté, et C la concentration à l'équilibre). L'équa- tion de Fowler-Guggenheim KC=~3/(1~3) Exp (2 ~ W/RT) conduit à la déter- mination de l'énergie d'interaction W entre molécules adsorbées et à une constante d'équilibre K. Par contre, dans l'équation de Hill et de De Boer KlC=~/(1~)) Exp [~/(1~) - K2~/RTI, K2 représente une constante d'énergie d'interaction entre molécules adsorbées et, dans celle de Kiselev KIC=~3/[(1+ ~) (1 + Kn~3)]~ Kn est une constante de formation de complexe éventuel entre molécules adsorbées. On vérifie que l'application de la relation de Temkin est satisfaisante pour tous les composés étudiés et permet de les classer selon leur affinité sur le charbon mais les résultats obtenus en utilisant les équations suivantes (Fowler ...) montrent qu'il n'y aurait pas de formation de complexe ou d'interaction entre molécules adsorbées.
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Fabre, B., J. Ayele, M. Mazet, and P. Lafrance. "Adsorption du pentachlorophenol sur divers matériaux : Influence de co-adsorbats organiques (Substances humiques et lindane)." Revue des sciences de l'eau 3, no. 3 (April 12, 2005): 277–92. http://dx.doi.org/10.7202/705075ar.
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Nous avons réalisé, pour de faibles concentrations, l'étude de l'adsoprtion d'un pesticide le pentachlorophénol, sur plusieurs matériaux adsorbants : le charbon actif, la kaolinite et la bentone. Les résultats montrent que l'adsorption du pentachlorophénol sur la kaolinite reste négligeable tandis que la bentone SD-3 (argile traitée) permet d'obtenir des résultats intéressants avec toutefois une capacité maximale d'adsorption 10 à 100 fois plus faible que celle du charbon actif. Le charbon actif reste le meilleur matériau adsorbant pour le pentachlorophénol. La solubilité de ce composé étant très variable en fonction du pH du milieu on constate que l'adsorption du pentachlorophénol-pentachlorophénate (5 mg.l-1) diminue pour des valeurs de pH supérieures au pKa du couple acide-base que nous avons déterminé expérimentalement, égal à 5,9 ± 0,1. L'adsorption du pentachlorophénol n'est pas affectée par la présence d'acides humiques (obtenus à partir de substances commerciales) utilisés comme coadsorbats (10 mg.l-1) alors que les acides fulviques (20 mg.l-1) extraits de sols semblent provoquer une promotion de l'adsorption. On observe d'autre part que le pentachlorophénol n'affecte pas l'adsorption des acides humiques mais augmente légèrement celle des acides fulviques. Ces remarques suggèrent la possible formation d'un complexe acides fulviques-pentachlorophénol. Lorsqu'on utilise le lindane, pesticide hydrophobe comme coadsorbat (165 mg.l-1), on observe encore d'une façon systématique pour tous les nombreux essais une légère promotion de l'adsorption.
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Rasoulifard, Mohammad Hossein, Soghra Khanmohammadi, and Azam Heidari. "Adsorption of cefixime from aqueous solutions using modified hardened paste of Portland cement by perlite; optimization by Taguchi method." Water Science and Technology 74, no. 5 (June 14, 2016): 1069–78. http://dx.doi.org/10.2166/wst.2016.230.
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In the present study, we have used a simple and cost-effective removal technique by a commercially available Fe-Al-SiO2 containing complex material (hardened paste of Portland cement (HPPC)). The adsorbing performance of HPPC and modified HPPC with perlite for removal of cefixime from aqueous solutions was investigated comparatively by using batch adsorption studies. HPPC has been selected because of the main advantages such as high efficiency, simple separation of sludge, low-cost and abundant availability. A Taguchi orthogonal array experimental design with an OA16 (45) matrix was employed to optimize the affecting factors of adsorbate concentration, adsorbent dosage, type of adsorbent, contact time and pH. On the basis of equilibrium adsorption data, Langmuir, Freundlich and Temkin adsorption isotherm models were also confirmed. The results showed that HPPC and modified HPPC were both efficient adsorbents for cefixime removal.
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Ouattara, Victor Tiéba, Zoumana Konate, Gustave Francis Messoum, Emmanuel Koffi Kassin, Mathias Gnion Tahi, Louis Anselme Koko, Brahima Kone, Emmanuel Acka Dick, and Maméri Camara. "Effets de la fertilisation organo-phosphatée sur la fertilité en matière organique et complexe adsorbant d’un ferralsol sous cacaoyers dans la région de Divo (Côte d’Ivoire)." International Journal of Biological and Chemical Sciences 12, no. 6 (February 22, 2019): 2901. http://dx.doi.org/10.4314/ijbcs.v12i6.33.
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Botana-de la Cruz, Anakaren, Philip E. Boahene, Sundaramurthy Vedachalam, Ajay K. Dalai, and John Adjaye. "Mesoporous Adsorbents for Desulfurization of Model Diesel Fuel: Optimization, Kinetic, and Thermodynamic Studies." Fuels 1, no. 1 (November 14, 2020): 47–58. http://dx.doi.org/10.3390/fuels1010005.
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Mesoporous alumina-based adsorbents consisting of a π-electron acceptor complexing agent (2,7-dinitro-9-fluorenone) were synthesized and characterized. Adsorbents were screened for the removal of sulfur compounds from a model ultra-low-sulfur diesel fuel via a charge transfer complex (CTC) mechanism. The sulfur adsorption isotherms and kinetics were examined. The kinetics of sulfur adsorption followed a pseudo-second-order model with the CTC adsorbents. Among the three adsorbents screened, a commercial γ-Al2O3 CTC adsorbent showed the highest desulfurization in a short-run period. The regeneration of spent adsorbent was studied with three different polar solvents, namely chloroform, dichloromethane, and carbon tetrachloride. Dichloromethane was found to be the most suitable solvent for extracting a major portion of sulfur compounds occupied in the pores of the spent adsorbent. γ-Al2O3 CTC adsorbent can be reused after regeneration. Thermodynamic parameters such as Ea, ΔG, ΔH, and ΔS provided a better insight into the adsorption process.
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Gordon, Hungerford, Laycock, Ouwerkerk, and Fletcher. "Adsorbents for the Sequestration of the Pimelea Toxin, Simplexin." Proceedings 36, no. 1 (February 12, 2020): 90. http://dx.doi.org/10.3390/proceedings2019036090.
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Pimelea poisoning affects cattle grazing arid rangelands of Australia, has no known remedy and significant outbreaks can cost the industry $50 million per annum. Poisoning is attributable to consumption of native Pimelea plants containing the toxin simplexin. Charcoal, bentonite and other adsorbents are currently used by the livestock industry to mitigate the effects of mycotoxins. The efficacy of such adsorbents to mitigate Pimelea poisoning warrants investigation. Through a series of in vitro experiments, different adsorbents were evaluated for their effectiveness to bind simplexin using a simple single concentration, dispersive adsorbent rapid screening method. Initial experiments were conducted in a rumen fluid based medium, with increasing quantities of each adsorbent: sodium bentonite (Trufeed®, Sibelco Australia), biochar (Nutralick®Australia) and Elitox® (Impextraco, Belgium). Data showed the unbound concentration of simplexin decreased with increasing quantities of each adsorbent tested. Sodium bentonite performed best, removing ~95% simplexin at 12 mg/mL. A second experiment using a single amount of adsorbent included two additional adsorbents: calcium bentonite (Bentonite Resources, Australia) and a synthetic adsorbent (Waters, USA). The concentration of simplexin remaining in the solution after 1 h, the amount able to be desorbed off the adsorbent-toxin matrix with replacement fresh fluid, and the amount remaining bound to the adsorbent were measured. All samples containing an adsorbent were statistically different compared to the blank (p < 0.05), indicating some binding activity. Future work will explore the binding mechanisms and behaviour of the toxin-adsorbent complex in the lower gastrointestinal tract.
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Olufemi, Babatope Abimbola, and Anne Nlerum. "Parametric Statistical Significance of Iron (II) Ions Adsorption by Coconut Shell in Aqueous Solutions." NUST Journal of Engineering Sciences 11, no. 1 (March 10, 2019): 17–25. http://dx.doi.org/10.24949/njes.v11i1.285.
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The parametric statistical adsorption of chemically unmodified coconut shell powder (CSP) to adsorb iron (II) ions from aqueous solutions was examined in this work. It was observed that the adsorption capacity increased with increasing adsorbent dose, reducing adsorbate dose, increasing contact time, decreasing temperature and reducing particle size. As observed about one gram of the adsorbent was sufficient enough to remove 98 % iron (II) ions. A total contact time of about 40 minutes was sufficient for almost complete adsorption of the ions, while a pH of about 6.0 exhibited the maximum adsorption capacity. The sorption data were fitted into Langmuir, Freundlich, Temkin and the Dubinin-Radushkevich isotherms, fitted most with the Freundlich Isotherm model. The energy values obtained from the Temkin and Dubinin-Radushkevich isotherm model indicated high chemisorption phenomenon with the adsorbents. Investigation of some kinetic models confirmed that the adsorption of iron (II) ions using CSP was a pseudo-second order kinetic process, which further corroborates that chemisorption dominates the adsorption. Fourier Transform Analysis (FTIR) further established and justified the outcome of the study. The adsorption was parametrically justified statistically with Analysis of Variance (ANOVA) and Bonferroni-Holm Posthoc significance test. Conclusively, coconut shell proved strongly to be an effective and suitable adsorbent for removing iron (II) ions from aqueous solutions.
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Irdhawati, Irdhawati, Alling Andini, and Made Arsa. "DAYA SERAP KULIT KACANG TANAH TERAKTIVASI ASAM BASA DALAM MENYERAP ION FOSFAT SECARA BATH DENGAN METODE BATH." Jurnal Kimia Riset 1, no. 1 (August 29, 2016): 52. http://dx.doi.org/10.20473/jkr.v1i1.2443.
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AbstrakKulit kacang tanah digunakan sebagai adsorben untuk menyerap ion fosfat dalam larutan. Sebelum digunakan sebagai adsorben, kulit kacang tanah dicuci, dikeringkan, dihaluskan menggunakan blender dan diayak dengan ukuran partikel ≤ 100 mesh. Serbuk halus diaktifkan dengan asam (H2SO4) dan basa (NaOH) pada berbagai konsentrasi. Selanjutnya, adsorben dengan dan tanpa aktivasi digunakan untuk menentukan kadar fosfat yang terserap secara optimum. Parameter adsorpsi yang digunakan adalah waktu kontak dan kapasitas adsorpsi. Kapasitas adsorpsi diukur dengan mereaksikan ion fosfat dengan adsorben, dan sisa analit dalam larutan ditambahkan dengan amonium molibdat membentuk senyawa kompleks amonium fosfomolibdat berwarna biru dalam larutan asam. Konsentrasi senyawa kompleks ditentukan dengan metode spektrofotometri UV-Visible.Hasil dalam proses aktivasi menunjukkan konsentrasi optimum asam adalah 0,05 M, dan basa sebesar 0,5 M. Waktu kontak optimum diperoleh 45 menit untuk adsorben tanpa aktivasi dan aktivasi basa, sedangkan untuk aktivasi asam 30 menit. Kapasitas adsorpsi optimum berturut-turut adalah 8,5 mg/g; 8,8 mg/g, dan 10,4 mg/g menggunakan adsorben tanpa aktivasi, teraktivasi asam dan teraktivasi basa. Adsorben teraktivasi basa memiliki kapasitas adsorpsi tertinggi dibandingkan adsorben tanpa aktivasi dan teraktivasi asam. Kata kunci: kulit kacang tanah, ion fosfat, adsorpsi, amonium fosfomolibdat AbstractPeanut shell was used as adsorbent to adsorb phosphate ion in solution. Before using as adsorbent, the peanut shell was washed, dried, mashed and sifted with particle size <100 mesh. The fine powder was activated by acid (H2SO4) and base (NaOH) with various concentrations. Furthermore, the adsorbent with and without activation was used to determine the optimum phosphate concentration that can be adsorbed. The parameters adsorption such as contact time and adsorption capacity, were examined. The adsorption capacity was measured by reacting the phosphate ion with adsorbent, and the rest of analyte in the solution reacted with ammonium molybdate formed ammonium phospho molybdate complex compound whose blue color in acidic solution. The concentration of complex compound can be determined by UV-Visible spectrophotometry method. The results in activation process showed the optimum concentration of acid is 0.05 M, and base is 0.5 M. The optimum contact time obtained 45 minutes for adsorbent without and base activated, while 30 minutes for acid activated. The optimum adsorption capacity is 8.5 mg/g, 8.8 mg/g, and 10.4 mg/g using adsorbent without, acid, and base activated, respectively. Adsorbent in base activated has the highest adsorption capacity compared with no and acid activated. Keywords: peanut shell, phosphate ion, adsorption, ammonium phospho molybdate
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Baimatova, N., M. Derbissalin, A. Kabulov, and B. Kenessov. "Adsorption of Benzene, Toluene, Ethylbenzene and o-Xylene by Carbon-Based Adsorbents." Eurasian Chemico-Technological Journal 18, no. 2 (November 30, 2016): 123. http://dx.doi.org/10.18321/ectj433.
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This study explored the possibility of applying different carbon-based adsorbents for removal of benzene, toluene, ethylbenzene and o-xylene (BTEX) from indoor air in static and dynamic modes. To determine BTEX removal effectiveness, the approach based on solid-phase microextraction (SPME) in combination with gas chromatography – mass spectrometry (GC-MS) was used. In static mode, removal effectiveness of BTEX from indoor air using different carbon-based adsorbents (shungite, walnut shell, saxaul, apricot pits, activated charcoal, Tenax, carbon black) varied from 80% to 100%. Optimal preparation conditions for shungite-based adsorbent are no activation and addition of NaOH at 1:0.8 ratio. Shungite-based adsorbent was not able to remove BTEX from polluted indoor air at the flow rate 300 mL/min corresponding to the linear flow rate 25 cm/s, a minimum value for most commercial air purification systems. At the flow rate 75 mL/min (6.25 cm/s), a saturation time of shungite-based adsorbent made up 368 min for benzene and 437 min for toluene. At this flow rate, BTEX adsorption capacities of the shungitebased adsorbent were 0.3, 2.1, 0.2 and 0.3 μg/g, respectively. Compared to shungite, activated charcoal allowed the complete removal of BTEX at both flow rates in the whole studied time frame. Thus, shungite-based adsorbents are not recommended for BTEX removal from air because of much greater efficiencies of classic activated charcoal adsorbents. Applied methodology based on SPME-GC-MS allowed simple, fast and inexpensive collection of data and can be recommended as the analytical for developing new adsorbents and systems for air purification.
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Chernykh, Oleg Yu, Petr A. Krasochko, Irina A. Krasochko, Aleksey I. Albulov, Viktor N. Dubinich, and Marina V. Dubinich. "Development of complex adsorbent of mycotoxins BIOTOKS." Veterinaria Kubani, no. 1 (February 27, 2020): 19–22. http://dx.doi.org/10.33861/2071-8020-2020-1-19-22.
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Summary. Mycotoxins are secondary low molecular weight metabolites of micromycetes. These compounds most often contaminate feed and products of plant and animal origin. More than 400 mycotoxins have been described, of which 47 are highly toxic. For the prevention of mycotoxicosis of farm animals and poultry in the process of intensive management of animal husbandry, organic, inorganic and complex mycotoxin adsorbents are used. The complexity of adsorption of secondary metabolites of micromycetes is caused by the heterogeneous physicochemical properties of both the mycotoxins (molecular polarity, molecular weight, etc.) and adsorbents. We investigated the general sorption capacities of organic and inorganic components for designing the mycotoxin adsorbent and the «Biotox» complex mycotoxin adsorbent, as well as the degree of adsorption and desorption of regulated mycotoxins when interacting with some modifications of chitosan. As a result of the research, it was found that chitosan succinate (150.13 ± 0.17) and spirulina (142.12 ± 0.10) have the highest total sorption capacity. When determining the level of adsorption of regulated mycotoxins, it was established that all modifications of chitosan effectively bind toxic metabolites of micromycetes. However, based on the results of studies of the total sorption capacity, data on the sorption and desorption of mycotoxins and the dynamics of the processes, chitosan succinate has the best performance. To construct the complex adsorbent of mycotoxins, we used: Tripoli (as a mineral component), chiosan succinate (as an organic adsorbent and at the same time as a prebiotic), lacto-and bifidobacteria to restore the intestinal microflora in mycotoxicosis. Adsorbents with different contents of modified chitosan were developed: 3% and 10%, with a total sorption capacity of 30.04 ± 0.02 mg / g. and 91.3 ± 0.05 mg / g. respectively.
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Kumawat, Priyanka, Rashmi Sharma, and Arun K. Sharma. "A Comparative Adsorption Study on Low-cost Synthetic, Nano and Doped ZnO for the Removal of Copper Surfactants Urea Complexes: Equilibrium, Kinetics, and Thermodynamics." Nanoscience & Nanotechnology-Asia 10, no. 6 (November 30, 2020): 790–805. http://dx.doi.org/10.2174/2210681209666190723120309.
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Background: The effective removal of heavy metals from aqueous wastes is among the most important issues for many industrialized countries. Present paper reports about the synthesis of copper neem urea complex (CNU) and its characterization using elemental and spectroscopic techniques such as IR, NMR, and ESR. Methods: The NPs of ZnO and doped with SiO2 which was extracted from industrial ash’s) was synthesized by precipitation method and characterized through UV, SEM-EDX and XRD techniques. Three low cost adsorbents such as synthetic ZnO, nano ZnO and doped ZnO with SiO2 were chosen for the adsorption of copper surfactant complex of urea from non-aqueous solutions i.e. petroleum ether. Effect of various parameters like contact time, pH, adsorbent dosage, temperature and initial metal concentration on the removal through degradation and adsorption of CNU were investigated and optimized. Results: Isothermal studies indicated that the adsorption of CNU followed Langmuir adsorption isotherm. Kinetic studies indicated that removal of the CNU by the three adsorbents followed second order kinetics. With a maximum adsorption capacity of 7.58 mg/g using all three adsorbents showed an effective and efficient removal 95.8% of CNU from non-aqueous solutions by using ZnO doped with SiO2 compare to synthetic ZnO and nano ZnO. This is the first report of removal of the CNU complex based on the three adsorbents. Conclusion: The potential of application for the treatment of solutions containing these complexes in multi-metal solutions is indicated.
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Dudarev, Vladimir I., Nadezhda V. Irinchinova, and Elena G. Filatova. "ADSORPTION OF IONS OF NICKEL (II) FROM WATER SOLUTIONS WITH CARBON ADSORBENTS." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 60, no. 1 (March 1, 2017): 75. http://dx.doi.org/10.6060/tcct.2017601.5455.
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For citation:Dudarev V.I., Irinchinova N.V., Filatova E.G. Adsorption of ions of nickel (II) from water solutions with carbon adsorbents. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 1. P. 75-80.Adsorption methods of cleaning remains beyond comparison for deep extraction of heavy metal ions from dilute solutions. Their practical application allows achieving the high efficiency of wastewater treatment with minimal impact on the environment. It is known that nickel is one of carcinogenic elements. Thus, free nickel ions (II) are twice toxic than complex compounds. The maximum content of nickel ion (II) at the production of spent electroplating solutions is 50 mg/l, in washing waters – from 2 to 5 mg/l. In this paper we studied the adsorption capacity of carbon adsorbents IPI-T, synthesized from waste phenol-formaldehyde resin with respect to the nickel ions (II). Carbon аdsorbents IPI-T are black granules of irregular shape with an average particle size from 2 to 5 mm, and a surface area of 480 m2/g. Adsorption equilibrium time in static conditions corresponding to the constancy of the concentration of heavy metal ions in solution was four hours. A study of the adsorption capacity of carbon adsorbents IPI-T was performed at pH of 9.5. The adsorption process accompanied by the slight decrease in pH. Isotherms were build according to the results of research of adsorption at different temperatures. The shape of the isotherms obtained corresponds to poly-molecular adsorption. The resulting isotherms were processed using adsorption models of BET and Dubinin-Radushkevich. It was shown that the adsorption process model is best described by BET. Model Dubinin-Radushkevich was used to calculate the free energy of adsorption. The value of the free energy of adsorption indicates that the binding of nickel ion (II) has a physical nature. It was found that with the temperature increasing the adsorption capacity of carbon adsorbents IPI-T decreases. The dynamic activity of the adsorbent was characterized by the time of beginning of pass of the adsorbate till «breakthrough». Maximum protective effect of the adsorbent was 5 hours, and it was recovered 150 mg of nickel ions (II). The effectiveness of wastewater treatment of galvanic production from heavy metal ions was not less than 98%.
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Folens, Karel, Alebel Abebe, Jingyue Tang, Frederik Ronsse, and Gijs Du Laing. "Biosorption of residual cisplatin, carboplatin and oxaliplatin antineoplastic drugs in urine after chemotherapy treatment." Environmental Chemistry 15, no. 8 (2018): 506. http://dx.doi.org/10.1071/en18115.
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Environmental contextPlatinum complexes are widely used to treat cancer; however, these compounds are also rapidly excreted in the urine of patients and can therefore enter waterways, presenting a toxic hazard to the environment. The biopolymer chitosan was found to be an effective and fast adsorbent for capturing multiple platinum complexes currently applied in medicine. This new approach using biomaterials is proposed to treat such drug residues while at the same time recovering the valuable metal from urine. AbstractThe majority of platinum used in antineoplastic drugs is rapidly excreted through the urine. These residual platinum compounds are highly toxic, and may eventually reach the aquatic environment if not remediated. Furthermore, platinum is a precious metal that is also relatively scarce, and it is therefore also economically worthwhile to capture and recycle it. We propose that biomass-derived adsorbents would be effective for recovering platinum from diluted streams, including synthetic human urine. Compared with ultrapure water, the salts and small biomolecules present in urine pose additional competition for active binding on the biosorbents’ surface. Chitosan, biochar, wood ash and granular activated carbon were found to effectively adsorb between 0.23 and 0.97mgg−1 inorganic PtIV when a minimal adsorbent dose of 10gL−1 was applied. The fastest adsorption rate was observed using chitosan (k2=728gmg−1min−1), followed by wood ash (k2=49.4gmg−1min−1) and biochar (k2=6.18gmg−1min−1). Substantial differences in platinum recovery were observed among inorganic PtIV, cisplatin, carboplatin and oxaliplatin, which indicates that the adsorbate speciation is highly important for establishing a hydrometallurgical purification technique.
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Dmytruk, Andriy, and Volodymyr Ovechko. "Spectral Investigation of Physical Adsorption in Porous Glass." Surface Review and Letters 10, no. 02n03 (April 2003): 289–93. http://dx.doi.org/10.1142/s0218625x03005517.
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An oscillators model of physical adsorption on a silica surface has been built considering the molecular adsorbent-adsorbate complex as two relatively individual parts united by a weak van der Waals interaction. An experimental study of the NIR spectra of ammonia and p-xylene molecules adsorbed in a porous glass has been carried out. Theory and experiment agree well.
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Trofimchuk, A. K., S. L. Didukh, A. N. Mukhina, and V. N. Losev. "Preconcentration And Determination Of Nickel Ions Using Silica With Functional Groups Of Sulfonic Derivatives Of Nitroso Naphthols." Methods and Objects of Chemical Analysis Vol. 14, No.1 (2019): 30–36. http://dx.doi.org/10.17721/moca.2019.30-36.
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Silica based adsorbents modified with polyhexamethylene guanidine and sulfonic derivatives of nitroso naphthols - nitroso-N salt (NNS) and nitroso-R salt (NRS), have been proposed for preconcentration and solid-phase photometric determination of Ni(II) in industrial solutions. Adsorbents with the surface concentration of the reagents of 1.5 and 3 μmol/g have been studied. Adsorbents with NNS functional groups quantitatively extract Ni(II) at pH 5.5-7.5, while with NRS functional groups – at pH 5.5-7.0, giving complex compounds with the composition Ni(II) : Reagent = 1 : 3. After Ni(II) adsorption the adsorbents became orange (λ = 510 нм) or brown (λ = 490 нм) for NNS and NRS respectively. The pH range of maximum color intensity coincides with the pH range of the quantitative extraction of Ni(II). The procedure of solid-phase photometric determination of Ni(II) in form of diffuse reflectance spectroscopy has been developed. The analytical range of the procedure is 0.1 – 3.0 μg of Ni(II) per 0.1 g of the adsorbent with the surface concentration of the reagent of 1.5 μmol/g and 0.15 – 6 μg of Ni(II) per 0.1g of the adsorbent with the surface concentration of the reagent of 3 μmol/g. The procedure was used for determination of Ni(II) in the rinsing and waste waters of galvanic manufactory. The results accuracy was confirmed by ICP-OES analysis.
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Khudayberganova, Nagima, Abdumalik Rizaev, and Eldor Abduraxmonov. "Adsorption properties of benzene vapors on activated carbon from coke and asphalt." E3S Web of Conferences 264 (2021): 01022. http://dx.doi.org/10.1051/e3sconf/202126401022.
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The industry produces a variety of wastes in production processes. This has a negative impact on the state of ecological balance. Today, in the oil industry, many different types of oil waste are accumulated as reserves. Focusing them on targeted production is one of the most pressing issues today. The use of a high-vacuum adsorption device is important in producing adsorbents from coke and asphalt from residual oil products and in the complete determination of the sorption properties of the obtained adsorbents. Benzene and toluene adsorption isotherms, the sorption volume, and properties of the new adsorbent can be described in detail by studying the adsorption heat.
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Garbacz, Jerzy K., Mariusz Kozakiewicz, and Barbara Rymian. "Phenomenological Variant of Quasi-Chemical Approximation in the Description of the Dimerisation of Adsorbate Molecules in a Multilayer Adsorption Phase on a Homogeneous Surface." Polish Hyperbaric Research 68, no. 3 (September 1, 2019): 33–40. http://dx.doi.org/10.2478/phr-2019-0011.
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Abstract This article is related thematically to two of our earlier publications, which demonstrated full equivalence of statistical and phenomenological methods in the description of physical gas adsorption on the surface of a solid body, and the fundamental possibility of analytical solution of adsorbate-adsorbate association problems in the entire multi-layer adsorption phase. The quasi-chemical scheme of secondary interactions leading to the formation of horizontal multimolecular adsorption complexes has been elaborated. A new adsorption equation was formulated taking into account the dimerisation of adsorbed molecules in the whole adsorption phase, as well as the influence of topography of the binding sites of adsorbent surfaces on the form of this solution.
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Parvin, Shahanaz, Al Mamun, Md Fazle Rubbi, Md Abdur Ruman, Md Moshiur Rahman, and Biplob Kumar Biswas. "Utilization of egg-shell, a locally available biowaste material, for adsorptive removal of congo red from aqueous solution." Aceh International Journal of Science and Technology 9, no. 2 (September 7, 2020): 63–74. http://dx.doi.org/10.13170/aijst.9.2.16767.
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Egg-shell, a locally obtainable biowaste material, was successfully used for common textile dye (congo red) removal from synthetic wastewater solution. All adsorptive experiments were carried out in a batch method. Experiments were conducted to understand the consequence of different functioning parameters, for example, the pH of the solution, adsorbent dosage, reaction time, and initial adsorbate concentration. The surface morphology of the egg-shell was analyzed by scanning electron microscopy (SEM) images of the adsorbent (before as well as after adsorption) showed that there was a change in surface morphology, which ensured the congo red adsorption on the adsorbent surface. The adsorbent dose was determined to be 1g as optimum value, while the solution pH 5 was seemingly the best operating pH at the tested conditions. Complete adsorption was achieved in 120 min while the pseudo-second-order kinetic model portrayed the sorption kinetics quite nicely. Langmuir adsorption model (monolayer adsorption) was the best-suited model for describing the sorption process in the concern of the correlation coefficient. The values of dimensionless separation parameters (RL) signified that the adsorption process was promising for all studied concentrations. A considerably great extent of sorption capacity (153.85 mg/g) of egg-shell adsorbent indicated that it could be employed for wastewater treatment in textile and related industries
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Giraldo, Liliana, Paola Rodriguez-Estupiñán, and Juan Carlos Moreno-Piraján. "Isosteric Heat: Comparative Study between Clausius–Clapeyron, CSK and Adsorption Calorimetry Methods." Processes 7, no. 4 (April 10, 2019): 203. http://dx.doi.org/10.3390/pr7040203.
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This work presents the calorimetric study of five adsorbents with different chemical and textural characteristics: MOF-199, MCM-41, SBA-15, activated carbon prepared from corn cob (GACKP) and graphite. These solids were used to establish the differences between isosteric heats evaluated by three different methods: Clausius–Clapeyron (C-C), Chakraborty, Saha and Koyama (CSK) and Adsorption Calorimetry (A-Cal). The textural characterization results show solids that have values of specific surface area between 2271 m2·g−1 for the MOF-199 and 5.2 m2·g−1 for the graphite. According to the results obtained for the isosteric heats for each sample, the magnitude varies depending on the coverage of the adsorbate and the textural characteristics of each adsorbent. Solids with an organized structure have isosteric heat values that are coincident among the three methods. Meanwhile, heterogeneous solids such as activated carbon values evaluated by the CKS and C-C have a high dispersion method regarding the adsorption calorimetry method. The results obtained show that the adsorption calorimetry, being a direct experimental measurement method, presents less dispersed data. At low quantities, the isosteric heat of nitrogen adsorption decreased in the order MOF-199, GACKP, MCM-41, SBA-15 and Graphite. The order for the isosteric heats values was coherent with the surface characteristics of each of the solids, especially with the pore size distribution. Finally, throughout the coverage examined in this work, the isosteric heats for nitrogen adsorption determined by adsorption calorimetry (A-Cal) were larger than the evaluated by C-C and CSK indirect methods of vaporization. According to the results, it is shown that the adsorption calorimetry allows values of the isosteric heats of adsorption with an error of less than 2% to be established and also reveals the complex nature of the heterogeneity or homogeneity of the adsorbent.
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Jaid, Ghaidaa Majeed, Azhar Jabbar Bohan, and Ghaed Khalaf Salman. "Artificial Neural Network Modeling for Removal of Cd (II) and Pb (II) from Wastewater by Using Three Ferrite Nanomaterial (Cu0.9Zn0.1Fe2O4, Cu0.8Zn0.2Fe2O4, and Cu0.7Zn0.3Fe2O4) and Study the Antimicrobial Effectiveness of these Ferrite Substances." Revista de Chimie 71, no. 10 (November 3, 2020): 67–80. http://dx.doi.org/10.37358/rc.20.10.8351.
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Adsorption of Pb(II) and Cd(II) from wastewater utilizing three nano-magnetic materials (Cu0.9Zn0.1Fe2O4, Cu0.8Zn0.2 Fe2O4, and Cu0.7Zn0.3 Fe2O4) were studied. The nano-magnetic materials were prepared from the Cu Frites powder and then the Cu ions were replaced by Zn ions in three concentrations, these materials were characterized by X-ray diffraction (XRD) which has conformed good crystallinity with spinel structure and particle size in the range (26.5�23.9 nm). Artificial neural networks were applying to model the removal of Pb(II) and Cd(II) on three adsorbents from wastewater. The operating conditions that affect on adsorption process are adsorbent dose (0.1, 0.25, and 0.5) g, pH (3, 7, and 9), and contact time (15, 30, and 45) min. Three Multilayered feed-forward neural networks (3:9:2) were successfully used for modeling of removing heavy metals on three adsorbents. The antimicrobial effectiveness of ferrite substances was studied against two types of bacteria. The three adsorbents showed an excellent removal for Cd (II) ions 100% complete removal on Cu0.9Zn0.1 Fe2O4, Cu0.8Zn0.2 Fe2O4, and it was 95% on Cu0.7Zn0.3 Fe2O4, and less removal for Pb (II) ions on Cu0.9Zn0.1Fe2O4, Cu0.8Zn0.2 Fe2O4 were 78.4% and 78.8%, and 83.4% on Cu0.7Zn0.3 Fe2O4. ANN models show efficient simulation with a high correlation coefficient (R2 = 0.99) for all three adsorbents, Sensitivity Analysis demonstrated that pH, time, and a dose of the adsorbent have a strong impact on the process of removal.The results for antimicrobial effectiveness showed that Cu0.9Zn0.1 Fe2O4 had the most antibacterial properties against two types of bacteria and the S. aureus killing rate was less than the E. coli killing rate of all ferrite composite nanoparticles.
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Assaf, Jean Claude, Sahar Nahle, Ali Chokr, Nicolas Louka, Ali Atoui, and André El Khoury. "Assorted Methods for Decontamination of Aflatoxin M1 in Milk Using Microbial Adsorbents." Toxins 11, no. 6 (May 29, 2019): 304. http://dx.doi.org/10.3390/toxins11060304.
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Aflatoxins (AF) are carcinogenic metabolites produced by different species of Aspergillus which readily colonize crops. AFM1 is secreted in the milk of lactating mammals through the ingestion of feedstuffs contaminated by aflatoxin B1 (AFB1). Therefore, its presence in milk, even in small amounts, presents a real concern for dairy industries and consumers of dairy products. Different strategies can lead to the reduction of AFM1 contamination levels in milk. They include adopting good agricultural practices, decreasing the AFB1 contamination of animal feeds, or using diverse types of adsorbent materials. One of the most effective types of adsorbents used for AFM1 decontamination are those of microbial origin. This review discusses current issues about AFM1 decontamination methods. These methods are based on the use of different bio-adsorbent agents such as bacteria and yeasts to complex AFM1 in milk. Moreover, this review answers some of the raised concerns about the binding stability of the formed AFM1-microbial complex. Thus, the efficiency of the decontamination methods was addressed, and plausible experimental variants were discussed.
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Zaytsev, Dmitriy S., Andrey V. Tvardovskiy, Andrey V. Shkolin, and Anatoliy A. Fomkin. "ADSORPTION DEFORMATION OF MICROPOROUS CARBON ADSORBENT FAS AT ADSORP-TION OF WATER AND ACETONE VAPORS." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 62, no. 2 (February 7, 2019): 43–47. http://dx.doi.org/10.6060/ivkkt.20196202.5807.
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For the first time, complex studies were carried out on adsorption deformation – sorbostriction of microporous carbon adsorbent FAS at adsorption of water and acetone vapors from the flow of carrier gas – nitrogen in non-equilibrium conditions. The results of this phenomenon were analyzed and the laws of the sorption of the microporous carbon adsorbent FAS during the adsorption of substances of different classes and different purposes in non-equilibrium conditions are established. In work a microporous carbon adsorbent FAS, obtained on the basis of furfural was used. Active coals on the basis of thermosetting plastics grades of FAS are significantly better than commercially-produced carbon adsorbents based on coal and peat on their mechanical properties and low ash content at a much greater development of the volume of the adsorbent micropores. We used the facility for studies of adsorption deformation of a solid adsorbent, manufactured in the Institute of Physical Chemistry and Electrochemistry of RAS. For the measurements we used a flow dilatometer, allowing measuring the adsorption deformation of the adsorbent while passing through it portions of the test substance or mixture in the carrier gas flow. It is shown that exit time of curves of sorbostriction to the maximum is individually for each of the studied substances, which enables you to use the effect of sorbostriction to detect the presence of certain substances in the mixture. The results of the wave sorbostriction of microporous carbon adsorbent FAS at adsorption of water and acetone vapors from the flow of carrier gas - nitrogen allow to conclude on the high selectivity of adsorption and the possibility of using the adsorbent as a sensor to control the content of these substances in a flow of nitrogen.
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A. Bezdeneznych, L., O. V. Kharlamova, and V. M. Shmandiy. "Composite Granulated Adsorbents Based on Chitosan and Agricultural Processing Waste for Sewage Treatment." International Journal of Engineering & Technology 7, no. 4.3 (September 15, 2018): 320. http://dx.doi.org/10.14419/ijet.v7i4.3.19825.
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To minimize the impact of industrial enterprises on water objects, a wide variety of adsorbents (based on activated carbon, natural materials, nanomaterials, vegetable waste of agro-industrial complex, etc.) is used. Recently, chitin and chitosan have attracted the attention of scientists due to a number of unique physico-chemical and biological properties (adsorption, antioxidant, radioprotective, immunomodulating, lamina-forming). We have improved the method of obtaining powdered chitosan and established the basic physical and chemical parameters (bulk density, humidity). The method of obtaining chitosan granules and composite materials based on chitosan and modified sunflower husks (MSH) has been further developed by the "drip method". The adsorption properties of powder chitosan, chitosan granules and MSH were studied. It is set that a granular adsorbent has a high adsorbtivity in comparing to the original chitosan. Efficiency of wastewater treatment with the use of chitosan granules and MSH is equally high (up to 98%). The optimum amount of adsorbent for effective cleaning of contaminated water is 1% of its volume. The use of the results of the conducted research allows us to obtain an effective adsorbent for the treatment of industrial waste water.
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GUO, CAIXIA, TIANLI YUE, SHAIMAA HATAB, and YAHONG YUAN. "Ability of Inactivated Yeast Powder To Adsorb Patulin from Apple Juice." Journal of Food Protection 75, no. 3 (March 1, 2012): 585–90. http://dx.doi.org/10.4315/0362-028x.jfp-11-323.
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This study aimed to investigate the adsorption of patulin from apple juice, using two types of inactivated yeast powder: laboratory-prepared yeast powder (LYP) and commercial yeast powder (CYP). The effects of incubation time, pH, incubation temperature, adsorbent amount, and initial concentration of patulin and the stability of the yeast-mycotoxin complex were assessed. The results showed that the efficiencies of the two yeast types in adsorbing patulin were similar. The ability of the powders to remove patulin increased with longer incubation times, and patulin concentration was below detectable levels with LYP and CYP at approximately 36 and 30 h, respectively. The highest removal of patulin was achieved at pH 5.0 for both powder types, and there were no significant differences in patulin decrease at different temperatures (4, 29, and 37°C). Additionally, the adsorption percentage of patulin increased significantly with the increase of absorbent amount and decrease of initial concentration of patulin. Stability of the yeast-patulin complex was assessed, and patulin was more stable when washed in phosphate-buffered saline (pH 4.0) than in absolute ethyl alcohol. These results suggest that inactivated yeast powder has potential as a novel and promising adsorbent to bind patulin effectively.
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Qurie, Mohannad, Mustafa Khamis, Adnan Manassra, Ibrahim Ayyad, Shlomo Nir, Laura Scrano, Sabino A. Bufo, and Rafik Karaman. "Removal of Cr(VI) from Aqueous Environments Using Micelle-Clay Adsorption." Scientific World Journal 2013 (2013): 1–7. http://dx.doi.org/10.1155/2013/942703.
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Removal of Cr(VI) from aqueous solutions under different conditions was investigated using either clay (montmorillonite) or micelle-clay complex, the last obtained by adsorbing critical micelle concentration of octadecyltrimethylammonium ions onto montmorillonite. Batch experiments showed the effects of contact time, adsorbent dosage, and pH on the removal efficiency of Cr(VI) from aqueous solutions. Langmuir adsorption isotherm fitted the experimental data giving significant results. Filtration experiments using columns filled with micelle-clay complex mixed with sand were performed to assess Cr(VI) removal efficiency under continuous flow at different pH values. The micelle-clay complex used in this study was capable of removing Cr(VI) from aqueous solutions without any prior acidification of the sample. Results demonstrated that the removal effectiveness reached nearly 100% when using optimal conditions for both batch and continuous flow techniques.
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SEKI, Shigeki, Masashi NISHIDA, and Isao YOSHIDA. "Template Adsorbent Composed of Particles Impregnated with Pre-organized Ligand through Its Metal Complexes: Uranyl Ion-Selective Adsorbents." Analytical Sciences 17, no. 5 (2001): 585–86. http://dx.doi.org/10.2116/analsci.17.585.
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Zaytsev, Dmitriy S., Andrey V. Tvardovskiy, Andrey V. Shkolin, and Anatoliy A. Fomkin. "SORBOSTRICTION OF MICROPOROUS CARBON ADSORBENT FAS-3 AT ADSORPTION OF ORGANIC SUBSTANCES VAPORS FROM NITROGEN FLOW." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 60, no. 4 (May 12, 2017): 54. http://dx.doi.org/10.6060/tcct.2017604.5472.
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For the first time, complex studies were carried out on adsorption deformation – sorbostriction of microporous carbon adsorbent FAS-3 at adsorption of hexane, benzene and carbon tetrachloride from the flow of carrier gas – nitrogen in non-equilibrium conditions. The results of this phenomenon were analyzed. In work a microporous carbon adsorbent FAS-3, obtained on the basis of furfural was used. Active coals on the basis of thermosetting plastics grades of FAS are significantly better than commercially-produced carbon adsorbents based on coal and peat on their mechanical properties and low ash content at a much greater development of the volume of the adsorbent micropores. We used the facility for studies of adsorption deformation of a solid adsorbent, manufactured in the Institute of Physical Chemistry and Electrochemistry of RAS. For the measurements we used a flow dilatometer, allowing measuring the adsorption deformation of the adsorbent while passing through it portions of the test substance or mixture in the carrier gas flow. It is shown that values of the maxima on the curves of deformation increase with increasing the concentrations of the components of the mixture. The area under the curve of barbastelle depends on the amount of injected material in a flow of carrier gas. Exit time curves of barbastelle to the maximum is individually for each of the studied substances, which enables you to use the effect of barbastelle to detect the presence of certain substances in the mixture. The results of the wave sorbostriction of microporous carbon adsorbent FAS-3 at adsorption of benzene, hexane, carbon tetrachloride from the flow of carrier gas - nitrogen allow to conclude on the high selectivity of adsorption and the possibility of using the adsorbent as a sensor to control the content of these substances in a flow of nitrogen.For citation:Zaytsev D.S., Tvardovskiy A.V., Shkolin A.V., Fomkin A.A. Sorbostriction of microporous carbon adsorbent FAS-3 at adsorption of organic substances vapors from nitrogen flow. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 4. P. 54-59.
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Wu, Rong, Muhammad Zubair, and Aman Ullah. "Novel banana peel/graphene oxide derived biosorbent for water purification." Alberta Academic Review 2, no. 2 (October 15, 2019): 81–82. http://dx.doi.org/10.29173/aar76.
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More than 100 million tons of banana peels are produced annually, and about 40 million banana peels (40% of total weight) remain greatly unused. Hence, exploring banana peels’ ability to clean contaminated water would bring an additional value to the current “waste” product. One of the most common aspects of water pollution currently is heavy metal contamination, which is particularly dangerous for humans due to its high toxicity. Banana peels contain a high concentration of carbohydrates, the two most abundant being cellulose and starch, which has multiple hydroxyl and carboxyl functional groups. Banana peels are an easily available and cost-effective adsorbent that can adsorb different kinds of heavy metal ions. This research primarily focuses on improving the current efficiency of this technique through the development of a banana peel/graphene oxide hybrid adsorbent. The cross-linking graphene oxide possess numerous hydroxyl, carbonyl, carboxyl, and epoxide functional groups that can be used to induce chemical reactions with banana peel carbohydrates, providing the graphene oxide with additional functional groups. This modification can potentially increase the adsorption capacity of banana peel derived adsorbents. It is evident through FTIR analysis that banana peel powder and graphene oxide have many functional groups of similar types. Thus, reactions can readily occur to combine the two substances. The TGA analysis of both compounds, however, indicates different patterns of thermal decomposition. Further thermal analysis is required for the hybrid adsorbent. After the development and characterization of this hybrid adsorbent, the next step is to complete a water purification analysis. In the future, banana peel/graphene oxide derived adsorbent may serve as a sustainable and efficient solution for water purification.
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Ma, Chunyan, Fang Li, Caihua Wang, Miao He, Chensi Shen, Wolfgang Sand, and Yanbiao Liu. "Tuning the adsorption behaviour of β-structure chitosan by metal binding." Environmental Chemistry 15, no. 5 (2018): 267. http://dx.doi.org/10.1071/en18070.
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Environmental contextChitosan is an abundant natural component of marine life with potential applications as an adsorbant material for pollutants. We investigate the binding behaviour of chitosan, and show that the β-type structure readily chelates metal ions leading to enhanced adsorption of anionic pollutants in the chitosan-metal complex. The results are highly relevant to the removal of anionic organic pollutants from water. AbstractChitosan, which is commonly extracted from squid pens of the Loligo genus, has a β-type structure. Chitosan has potential application to the adsorption of pollutants but has received little study. We investigate the adsorption ability of β-structure chitosan as well as FeIII and AlIII chitosan-metal complexes. Pristine β-chitosan shows lower adsorption abilities for dye, CrVI and fluoride ions compared with those for α-chitosan, mainly owing to having fewer –NH3+ groups on its surface. However, the anionic pollutant adsorption efficiency of β-chitosan is clearly enhanced when chelated with metal ions. A β-structure chitosan-Fe-Al complex displayed adsorption capacities of 621.45 mg g−1 and 144.53 mg g−1 for Acid Red 73 dye and fluoride ions, respectively, according to the fitted Langmuir–Freundlich model; and of more than 173.03 mg g−1 for CrVI, according to the Freundlich model. These values are much higher than those observed for α-structure chitosan-metal complexes. This enhancement effect on the sorptive behaviour of β-chitosan can be attributed to its loose structure. The polymer chains of β-chitosan are arranged in parallel with relatively weak intermolecular forces, which allows them to easily chelate metal ions. Anionic pollutants can then be efficiently adsorbed by the chelated metal ions in the chitosan-metal complex if the electrostatic attraction of the –NH3+ groups is weak. This investigation provides a better understanding of β-chitosan-based adsorbents for application to anionic pollutant adsorption and removal.
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Castro-Castro, Johnatan D., Iván F. Macías-Quiroga, Gloria I. Giraldo-Gómez, and Nancy R. Sanabria-González. "Adsorption of Cr(VI) in Aqueous Solution Using a Surfactant-Modified Bentonite." Scientific World Journal 2020 (March 21, 2020): 1–9. http://dx.doi.org/10.1155/2020/3628163.
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Clay minerals can be modified organically by a cationic surfactant resulting in materials known as organoclays. The organoclays have been used as adsorbents of most of the organic contaminants in the aqueous solution and oxyanions of the heavy metal. In this study, a Colombian bentonite was modified with hexadecyltrimethylammonium bromide to obtain an organobentonite, and its capacity to adsorb Cr(VI) oxyanions in the aqueous solution was evaluated. The effect of pH, stirring speed, adsorbent amount, contact time, and ionic strength were investigated at 25°C. Stirring speeds above 200 rpm, contact times greater than 120 min, and the addition of NaCl (0.1 to 2.0 mM) did not have a significant effect on Cr(VI) removal. The influence of the adsorbent amount and pH on Cr(VI) adsorption was studied by the response surface methodology (RSM) approach based on a complete factorial design 32. Results proved that the Cr(VI) adsorption follows a quadratic model with high values of coefficient of determination (R2 = 95.1% and adjusted R2 = 93.9%). The optimal conditions for removal of Cr(VI) from an aqueous solution of 50 mg/L were pH of 3.4 and 0.44 g amount of the adsorbent. The adsorption isotherm data were fitted to the Langmuir and Freundlich adsorption isotherm models, and the model parameters were evaluated. The maximum adsorption capacity of Cr(VI) onto organobentonite calculated from the Langmuir model equation was 10.04 ± 0.34 mg/g at 25°C. The results suggest that organobentonite is an effective adsorbent for Cr(VI) removal, with the advantage of being a low-cost material.
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Buczek, Bronisław, and Wojciech Chwiałkowski. "Purification of the used palm oil by adsorption." Polish Journal of Chemical Technology 10, no. 1 (January 1, 2008): 19–21. http://dx.doi.org/10.2478/v10026-008-0005-7.
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Purification of the used palm oil by adsorption The components of fresh vegetable oils are mainly non-polar. During frying of food, complex and multistage reactions occur in the oil, which produce various polar compounds. Active carbons are characterized by small contents of polar functional groups, which are responsible for adsorbing such polar compounds. Effective purification of the used frying oils must involve the removal of the polar substances. To improve the quality of the used palm oil, an active carbon oxidized by a hydrogen peroxide treatment was used. Such a carbonaceous adsorbent improves the quality of the oil used for frying food by purifying it from colour substances, lipid hydrolysis products, oxidation products and total polar compounds.
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Pettersson, K., T. Piironen, M. Seppälä, L. Liukkonen, A. Christensson, M. T. Matikainen, M. Suonpää, T. Lövgren, and H. Lilja. "Free and complexed prostate-specific antigen (PSA): in vitro stability, epitope map, and development of immunofluorometric assays for specific and sensitive detection of free PSA and PSA-alpha 1-antichymotrypsin complex." Clinical Chemistry 41, no. 10 (October 1, 1995): 1480–88. http://dx.doi.org/10.1093/clinchem/41.10.1480.
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Abstract Generation of 15 monoclonal antibodies (MAbs) allowed construction of epitope maps and specific two-site immunofluorometric assays for free prostate-specific antigen (PSA) and PSA complexed with alpha 1-antichymotrypsin (ACT). Close correlation of PSA concentrations obtained with the use of different assays of free PSA suggested extensive similarity in immunodetection of free PSA in serum. Assays of the PSA-ACT complex overestimated the concentration of PSA-ACT in serum because of nonspecific adsorbance of ACT or cathepsin G-complexed ACT to the solid phase. This interference was substantially decreased in the presence of heparin. In studying the stability of purified PSA and PSA-ACT complexes formed in vitro, we found that the free PSA was stable during storage for 4 weeks at 35 degrees C, whereas PSA-ACT complexes largely dissociated in these conditions. The instability of PSA-ACT complexes was counteracted by storage at low temperatures, by adjusting the pH of the storage buffer between 6.8 and 7.4, and through addition of 100-1000-fold molar excess of native ACT. The ease of calibration and the accuracy of free PSA assays in comparison with assays of the PSA-ACT complex suggest that measurements of free to total PSA most accurately reflect the inverse of the proportion of PSA complexed to ACT in serum.
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Sur, Anirban, and Randip K. Das. "Numerical Modeling and Thermal Analysis of an Adsorption Refrigeration System." International Journal of Air-Conditioning and Refrigeration 23, no. 04 (December 2015): 1550033. http://dx.doi.org/10.1142/s2010132515500339.
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The aim of this paper is to develop a complete, precise and simple numerical model based on the thermophysical properties of an adsorptive cooling system (using activated carbon–methanol pair), analyze and discuss the heat and mass transfer processes and identify the parameters which influence the system performance. In the design of adsorption refrigeration system, the characteristics of both adsorbate–adsorbent pairs and system operating conditions are very important. So in this model, different thermophysical properties of working pair such as, specific heat, density, isosteric heat of adsorption and desorption, and different temperatures of the system are considered. A simulation code, written in FORTRAN, is carried out. The performance of the system is assessed in terms of refrigeration effect and coefficient of performance (COP).
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Chung, J. W., M. Breulmann, A. Clemens, C. Fühner, J. W. Foppen, and P. N. L. Lens. "Simultaneous removal of rotavirus and adenovirus from artificial ground water using hydrochar derived from swine feces." Journal of Water and Health 14, no. 5 (May 26, 2016): 754–67. http://dx.doi.org/10.2166/wh.2016.010.
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Hydrothermal carbonization technology can convert fecal waste into a valuable carbonaceous product referred to as hydrochar. We investigated the potential of fecal waste-derived hydrochar as an adsorbent for virus removal in water treatment. Swine feces was hydrothermally treated under two conditions: at 180 °C for 2 h and 230 °C for 7 h. The resulting solid products (hydrochar) were evaluated as virus adsorbents in water treatment. Simultaneous removal of pathogenic rotavirus (RV) and human adenovirus (HAdV) was investigated using a sand column set-up of 10 cm bed height with and without hydrochar supplement (1.5%, w/w). The removal efficiency of both viruses in a hydrochar-amended column was >3 log (complete removal). The amount of virus released in deionized water when flushed into the virus-retaining columns indicated that the secondary energy minimum played a more important role in RV retention than that of HAdV. Zeta-potential and hydrophobicity measurements on hydrochar materials indicated that the improved virus removal performance of hydrochar-amended columns was induced by the provision of extra hydrophobic surfaces. This study provides evidence that fecal waste-derived hydrochar can be used as a competent virus adsorbent.
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Aminy, Dini Elsi, Mudasir Mudasir, and Bambang Rusdiarso. "Immobilization of Dithizone on Natural Bentonite as Adsorbent of Cd(II) Ion." Key Engineering Materials 840 (April 2020): 22–28. http://dx.doi.org/10.4028/www.scientific.net/kem.840.22.
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Research on the adsorption of Cd (II) ion in dithizone-immobilized natural bentonite has been carried out. The aims of this research were focused on the preparation of dithizone-immobilized natural bentonite (BA-D) as adsorbent and desorption experiment of Cd(II) ion. The BA-D was prepared by adding dithizone (dissolved in toluene) into the activated natural bentonite. The adsorbents were characterized by FTIR and X-Ray Diffraction (XRD). This research showed that adsorption capacities of BA-A and BA-D were 1.70×10‒5 and 2.77×10‒5 mol g‒1 (46% of increasing). According to desorption experiment, interaction between activated natural bentonite and Cd(II) ionwere performed by electrostatic interaction, formation of hydrogen bond and complex formation.
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HASANABADI, Tahereh, Shahram LACK, Adel MODHEJ, Hossien GHAFOURIAN, Mojtaba ALAVIFAZEL, and M. Reza ARDAKANI. "Feasibility Study on Reducing Lead and Cadmium Absorption by Alfalfa (Medicago scutellata L.) in a Contaminated Soil Using Nano-Activated Carbon and Natural Based Nano-Zeolite." Notulae Botanicae Horti Agrobotanici Cluj-Napoca 47, no. 4 (November 28, 2019): 1185–93. http://dx.doi.org/10.15835/nbha47411613.
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The first risk posed by heavy metal pollution in an ecosystem is metal accumulation in the biomass of growing plants, which has harmful effects on human health. Natural-based nanoparticles are efficient in remediating environmental pollutants because they have a high surface/volume ratio, high chemical activity and produce no harmful side-products. The present study investigates the capacity of natural-based nano-porous adsorbents for reducing the availability of heavy metals to annual alfalfa (Medicago scutellata L.) roots and keeps them in soil. In a factorial experiment based on a randomized design (with four replications), three nano-adsorbents (nano-activated carbon, natural nano-zeolite and modified nano-zeolite) and two heavy metals (lead and cadmium) have been tested. The results demonstrated that applying the highest rate of activated carbon and modified nano-zeolite reduced shoot Pb content by 34% and 33.2%, and shoot Cd content by 35.5% and 46.7%, respectively, compared with the adsorbent-free control.
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In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 4, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue.
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Guo, Baihe, Yanlin Wang, Xin Shen, Xiaolei Qiao, Li Jia, Jun Xiang, and Yan Jin. "Study on CO2 Capture Characteristics and Kinetics of Modified Potassium-Based Adsorbents." Materials 13, no. 4 (February 15, 2020): 877. http://dx.doi.org/10.3390/ma13040877.
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In this paper, a silica aerogel support was prepared by two-step sol–gel method, and the active component K2CO3 was supported on the support by wet loading to obtain a modified potassium-based CO2 adsorbent. As the influences of reaction conditions on the CO2 capture characteristics of modified potassium-based adsorbents, the reaction temperature (50 °C, 60 °C, 70 °C, 80 °C), water vapor concentration (10%, 15%, 20%), CO2 concentration (5%, 10%, 12.5%, 15%), and total gas flow rate (400 mL/min, 500 mL/min, 600 mL/min) were studied in a self-designed fixed-bed reactor. At the same time, the low-temperature nitrogen adsorption experiment, scanning electron microscope, and X-ray diffractometer were used to study the microscopic characteristics of modified potassium-based adsorbents before and after the reaction. The results show that the silica aerogel prepared by the two-step sol–gel method has an excellent microstructure, and its specific surface area and specific pore volume are as high as 838.9 m2/g and 0.85 cm3/g, respectively. The microstructure of K2CO3 loaded on the support is improved, which promotes the CO2 adsorption performance of potassium-based adsorbents. The adsorption of CO2 by potassium-based adsorbents can be better described by the Avrami fractional kinetic model and the modified Avrami fractional kinetic model, and it is a complex multi-path adsorption process, which is related to the adsorption site and activity. The optimal adsorption temperature, water vapor concentration, CO2 concentration, and total gas volume were 60 °C, 15%, 12.5%, and 500 mL/min, respectively.
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Asgari, Ghorban, Bahman Ramavandi, and Sima Farjadfard. "Abatement of Azo Dye from Wastewater Using Bimetal-Chitosan." Scientific World Journal 2013 (2013): 1–10. http://dx.doi.org/10.1155/2013/476271.
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We introduce a new adsorbent, bimetallic chitosan particle (BCP) that is successfully synthesized and applied to remove the orange II dye from wastewater. The effects of pH, BCP quantity, and contact time are initially verified on the basis of the percentage of orange II removed from the wastewater. Experimental data reveal that the Cu/Mg bimetal and chitosan have a synergistic effect on the adsorption process of the adsorbate, where the dye adsorption by Cu/Mg bimetal, chitosan alone, and bimetal-chitosan is 10, 49, and 99.5%, respectively. The time required for the complete decolorization of orange II by 1 mg/L of BCP is 10 min. The Langmuir model is the best fit for the experimental data, which attains a maximum adsorption capacity of 384.6 mg/g. The consideration of the kinetic behavior indicates that the adsorption of orange II onto the BCP fits best with the pseudo-second-order and Elovich models. Further, the simulated azo dye wastewater can be effectively treated using a relatively low quantity of the adsorbent, 1 mg/L, within a short reaction time of 20 min. Overall, the use of BCP can be considered a promising method for eliminating the azo dye from wastewater effectively.
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Tabrizi, Nooshin Salman, and Maryam Yavari. "Preparation of Shaped Carbon Nanotube Composites with Porous Structures." Advanced Materials Research 829 (November 2013): 46–51. http://dx.doi.org/10.4028/www.scientific.net/amr.829.46.
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Porous structures of carbon nanotube (CNT) composites with highly accessible surface areas have numerous potential applications such as heterogeneous catalysts and adsorbents. In this study sodium alginate was added to CNTs dispersions as gelling agent. Before being dried, the hydrogels were shaped into bead, disk, and sheet forms. The alginate in the composites was then decomposed by heating up the samples under an inert gas. The morphology of the as-prepared composite was studied by scanning and transmission electron microscopy and the pore size distribution was measured by BJH method. The MWCNT composite showed a density of around 0.08 g/cm3 and a specific surface area of 164 m2/g. The as-synthesized porous composite was examined as an adsorbent to remove methylene blue (MB) from aqueous solutions. Complete removal of MB was observed. The adsorption isotherm and kinetics were also evaluated.
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Otto, K., and H. Sorek. "Adsorption Studies With Radiolabeled Zinc Dialkyldithiophosphate." Journal of Tribology 108, no. 3 (July 1, 1986): 340–44. http://dx.doi.org/10.1115/1.3261189.
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Adsorption of zinc di-n-octyldithiophosphate synthesized with radioactive 65Zn has been studied on iron, steel, silica, and carbon. Adsorption on iron powder in an inert atmosphere is described by Elovich kinetics and Langmuir type isotherms. Adsorption equilibrium was not complete even after ten days. Results indicate activated chemisorption with an apparent activation energy of 15 kJ/mol (3.6 kcal/mol) on relatively uniform adsorption sites. Adsorbent composition, oxygen concentration, and solution contaminants, such as methanol, strongly influence adsorption capacity. Monolayer coverage, derived from the Langmuir isotherm, is in reasonable agreement with differently derived literature values. Pronounced variations observed on different adsorbents are thought to be caused by catalytic decomposition or oxidation of ZDDP. Because of this sensitivity, it appears that laboratory studies with simplified systems cannot provide much information on the actual structure of an antiwear layer formed in practical multicomponent lubricants.
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Germán, Estefanía, Julio A. Alonso, Ewald Janssens, and María J. López. "C60Con complexes as hydrogen adsorbing materials." International Journal of Hydrogen Energy 46, no. 39 (June 2021): 20594–606. http://dx.doi.org/10.1016/j.ijhydene.2021.03.179.
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SRIPHUMRAT, Kunlanat, Phattaraporn THONGSAMAI, Montra CHAIRAT, Pilan SAENSUK, Nawee KUNGWAN, and Supaporn DOKMAISRIJAN. "Molecular Interactions and Binding Free Energy of Polydopamine and Methylene Blue: A DFT Study." Walailak Journal of Science and Technology (WJST) 17, no. 7 (July 1, 2020): 719–25. http://dx.doi.org/10.48048/wjst.2020.6511.
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Polydopamine (PDA) is a kind of mussel-inspired material. It has been applied as a coating and an adsorbent material. As an adsorbent, the PDA microspheres were used to remove methylene blue (MB) in aqueous solution. It was reported that the efficiency of the PDA adsorbent depends on the pH of the solution. Furthermore, in a pH range of 3 - 10, the hydroxyl and amine functional groups of PDA can be either protonated or deprotonated. The change of the net charge of PDA can affect the intermolecular interactions between PDA and MB. It was proposed that both of the electrostatic and p-p interactions should be dominant in the acidic and basic solutions. Therefore, the structural properties and intermolecular interactions of the PDA-MB complex should be investigated. Such an investigation can be useful for the improvement of the PDA microspheres for the other dyes. To get insight into the roles of PDA structure and its role as an interesting adsorbent for MB, the PDA-MB complex formation was carried out at pH 7. The PDA dimers which have six possible structures were selected. The optimization of all PDA dimers and MB was performed in the gas phase at the B3LYP/6-311++G(d,p) calculations. After that, the complex formation of the optimized PDA dimers and MB was performed using the AutoDock Vina V1.1.2. The binding free energy of the PDA dimers and MB was in a range of -3.2 to -3.7 kcal/mol, which indicated that the binding of PDA dimer and MB is spontaneous. The results showed that the p-p interaction between PDA dimer and MB plays a crucial role in the complex formation. Likewise, the sandwich-like structures of the complexes are more stable than the twisted structures.
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Hmamou, Mhamed, Fatima Ezzahra Maarouf, Bouchaib Ammary, and Abdelkebir Bellaouchou. "Surface Complexation of Chromium(VI) on Iron(III) Hydroxide: Mechanisms and Stability Constants of Surfaces Complexes." Indonesian Journal of Chemistry 21, no. 3 (February 26, 2021): 679. http://dx.doi.org/10.22146/ijc.60634.
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The adsorption of chromate ions H2-yA (y = 1, 2, and A = CrO42–) on iron(III) hydroxide was conducted as a function of adsorbent mass, solution pH, and hydration time. The surface complexation technique, based on the examination of the chromate distribution between the solid and liquid phases, was adopted to predict the adsorption mechanism. To specify stoichiometry of the chromate surface complexes, the proton (n > 0), and hydroxyl (n < 0) ion-exchange was evaluated at a pH range of 2–12. The obtained “n” values are ranging between -1 and 1. As a result, the sorption process involved specific chemical interaction with surface sites, resulting in 1H+ and 1OH– release of the adsorbate molecule. The surface species identified were ; ; ; ; ; ; ; and . The logarithmic values of their complexing constants were: log K00 = 1.81 ± 0.04; log K11 = -3.53 ± 0.07; log K21 = -1.03 ± 0.23, log K1-1 = 7.15 ± 0.14 and log K2-1 = 9.62 ± 0.53. The results showed that the chromate adsorption on Fe(III) hydroxide was of electrostatic and chemical nature at pH lower than 5.5, and only of chemical nature at pH superior to 5.5. Taking into account these considerations, Fe(III) hydroxide could be considered an excellent sorbent for the removal of Cr(VI) from wastewater solutions.
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Ikonomov, V., W. Samtleben, B. Schmidt, M. Blumenstein, and H. J. Gurland. "Adsorption Profile of Commercially Available Adsorbents: An in Vitro Evaluation." International Journal of Artificial Organs 15, no. 5 (May 1992): 312–19. http://dx.doi.org/10.1177/039139889201500511.
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Adsorbents from four commercially available devices, Protein A-Sepharose (Immunosorba Protein A-62,5; Excorim KB, Lund Sweden), Tryptophan-PVA (Immusorba TR-350; Asahi Medical Co., Tokyo, Japan), Phenylalanine-PVA (Immusorba PH-350; Asahi Medical Co., Tokyo, Japan), and Dextran sulfate (Liposorber LA-15; Kanegafuchi Chemical Co. Ltd, Osaka, Japan) were tested under optimal in vitro conditions to determine their adsorption capability for several plasma constituents which are usually the target of plasma therapy. The parameters of interest were: double stranded DNA-antibodies (anti-dsDNA), antiglomerular basement membrane antibodies (anti-GBM), antiacetylcholin receptor antibodies (AChRAb), circulating immune complexes (CIC), rheumatoid factor (RF), IgA, IgG, IgM, IgE, C3c, C4, LDL-cholesterol, total cholesterol, erythropoietin (EPO) and β2-microglobulin (β2M). The IgG auto antibodies, CIC and RF can be removed by Protein A-Sepharose, Try-PVA and Phe-PVA. IgG is best adsorbed by Protein A-Sepharose, while IgE can be removed effciently by Try-PVA. Dextran sulfate is without doubt the best adsorbent for LDL-cholesterol. All four adsorbents bind also complement components C3c and C4. No significant adsorption was found for EPO and β2M. The four devices exhibit a quite different adsorption profile which can be used as a guide for the optimal selection of an adsorption column in clinical apheresis.
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Ogata, Fumihiko, Megumu Toda, Masashi Otani, Takehiro Nakamura, and Naohito Kawasaki. "Evaluation of phosphate ion adsorption from aqueous solution by nickel-aluminum complex hydroxides." Water Science and Technology 2017, no. 3 (June 15, 2018): 913–21. http://dx.doi.org/10.2166/wst.2018.273.
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Abstract We prepared a variety of nickel-aluminum complex hydroxides, investigated their physicochemical properties, and evaluated their ability to adsorb phosphate ions (the molar ratios of nickel to aluminum, 1:2, 1:1, 2:1, 3:1, and 4:1, are referred to as NA12, NA11, NA21, NA31, and NA41). NA12 and NA11 have amorphous structures; their specific surface areas and the concentration of associated hydroxyl groups were greater than those of other adsorbents. The number of phosphate ions adsorbed onto NA12 and NA11 was greater than that onto other adsorbents. These results indicated that the phosphate ion adsorption is related to the specific surface area and the amount of hydroxyl groups. The adsorption isotherm data, and the effects of contact time and pH on the adsorption were investigated; our results implied that both the Freundlich equation model and the pseudo-second-order kinetic model describe the adsorption of phosphate ions by NA11. We showed that phosphate ions adsorbed onto NA11 can be desorbed by sodium hydroxide solution at different concentrations and that NA11 could be reused for at least three repeated cycles of phosphate ion adsorption and desorption. This study illustrates that NA11 has the potential for practical application as an adsorbent for phosphate ions from wastewater.
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Jagadeeswara Reddy, B., Sneha Latha Pala, Wondwosen Kebede Biftu, M. Suneetha, and Kunta Ravindhranath. "Effective removal of Cu2+ ions from polluted water using new bio-adsorbents." Water Practice and Technology 16, no. 2 (February 25, 2021): 566–81. http://dx.doi.org/10.2166/wpt.2021.019.
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Abstract Sorbents derived from stem powders of Feronia limonia (FLSP), Amorphophallus paeoniifolius (APSP) and Pumpkin (Cucurbitapepo) (PSP) plants are investigated for the removal of Cu2+ ions from polluted water by adopting batch methods of extraction. Extraction conditions are optimized for the effective removal of Cu2+ ions. High sorption capacities are observed: 175.5 mg/g for FLSP; 140.4 mg/g for APSP; 130.0 mg/g for PSP. Effective pH ranges are: 5 to 10 for FLSP; 6 to 10 for APSP and 7 to 10 for PSP. The three spent adsorbents can be regenerated and used. Thermodynamic parameters indicate that the adsorption process is spontaneous, endothermic and have positive change in entropy values. As ΔH values are more than 25.0 kJ/mole, the adsorption may be due to surface complex formation between Cu2+ ions and functional groups of the adsorbents viz., -OH, -COOH etc. in the effective pH ranges. The good adsorption behaviour of FLSP even in acidic pHs may be due to the ion-exchange of Cu2+ ions for H+ ions of the functional groups of the adsorbent. The Langmuir adsorption isotherm and pseudo second-order model describe well the adsorption process. The sorbents are effectively applied to treat effluents from Cu-based industries and polluted lake water.
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Ma, Jiaju, Zhiwei Lei, Yun Zhou, Tianhao Dong, Peizhuo Hu, Guojian Duan, and Tonghuan Liu. "Synthesis of selective biodegradable amidoxime chitosan for absorption of Th(IV) and U(VI) ions in solution." Radiochimica Acta 109, no. 5 (February 15, 2021): 343–55. http://dx.doi.org/10.1515/ract-2020-0122.
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Abstract Radionuclide extraction from wastewater is a long-term process, in which the study on the reuse and decomposition of adsorbents provides the ability to complete the post-treatment after adsorption. Herein, A novel biodegradable amidoxime chitosan has been synthesized through one-step without crosslinking agent and characterized by FT-IR, SEM, XPS, TGA and element analysis. The batch adsorption experiments of U(VI) and Th(IV) on AO-CTS adsorbent were studied and maximum adsorption of U(VI) and Th(IV) were 97 and 56 mg/g, respectively. The U(VI) and Th(Ⅳ) can be effectively desorbed from the AO-CTS materials at low acidity, The AO-CTS can be reused 6 times without reducing absorbency for U(VI) and Th(Ⅳ). When finish the adsorption process, the AO-CTS can be degraded by lysozyme at room temperature, there were no toxic or harmful substances are produced.
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Kheirabadi, Mahdieh, Majid Azizi, Seyedeh Faezeh Taghizadeh, and Yoshiharu Fujii. "Recent Advances in Saffron Soil Remediation: Activated Carbon and Zeolites Effects on Allelopathic Potential." Plants 9, no. 12 (December 5, 2020): 1714. http://dx.doi.org/10.3390/plants9121714.
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Saffron (Crocus sativus L.) is a highly valuable plant. Iran provides nearly 90% of the world’s total saffron and is the biggest global producer. The allelopathic effects of saffron corm (SC) and saffron field soil (SFS) have been hypothesized to play an important role in replanting. Recently, adsorbent materials have been used to neutralize the effects of allelochemicals. These materials, including activated carbon and zeolite, have large surface areas, pore volumes, as well as tremendous adsorptive capacity and complex chemical and physical properties. In this study, three independent experiments were conducted. In the first test, the allelopathic effects of aqueous and methanolic extracts of SC remnant and 9-year-old SFS as well as filtered aqueous extract of soil were investigated. In the second assay, the effects of SC remnants and SFS with different ages (i.e., 4, 6, and 9 years old) in combination with adsorbents were examined on the germination and growth of lettuce (Lactuca sativa L.) seedlings by the sandwich method. In the third experiment, we examined the effects of SC remnants combined with adsorbents on lettuce growth parameters. Our results showed that the allelopathic effects of aqueous and methanolic extracts of SC remnant were significantly superior to those of 9-year-old SFS. The aqueous extract of SC remnant reduced the root length of lettuce by 50%. The use of activated carbon and zeolites significantly decreased the observed allelopathic effect. Moreover, lettuce growth in rhizosphere soil was significantly inhibited by SC remnant and SFS extracts. The allelopathic effects of SC remnants caused a growth imbalance between the shoot and roots. Based on biochemical analyses, using the adsorbents increased the carotenoid content and chlorophyll index of lettuce by 23.33% and 5.25%, respectively. Adsorbents may play a role in treating soils contaminated by allelochemicals.
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Juengjarernnirathorn, S., M. Ohno, Y. Mishima, H. Suhara, and H. Araki. "Evaluation on applicability of a new hybrid adsorbent to waste pollution control in Lowland by complex leachate from waste landfill site." Lowland Technology International 17, no. 4 (2016): 225–32. http://dx.doi.org/10.14247/lti.17.4_225.
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Fedotov, Anatoliy V. "Energy-saving technologies of technical service and processing of organic waste." Tekhnicheskiy servis mashin, no. 1 (March 1, 2020): 65–75. http://dx.doi.org/10.22314/2618-8287-2020-58-1-65-75.
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Agricultural production in the Russian Federation is several times more energy-and material-intensive than in developed countries. (Research purpose) The research purpose is evaluation of the effectiveness of energy-saving technologies for technical maintenance of equipment using nanostructured aluminum oxyhydroxide and hydrothermal processing of agricultural waste in supercritical conditions. (Materials and methods) Nanostructured aluminum oxyhydroxide (boehmite) was produced by hydrothermal synthesis from aluminum powders. Tribological studies were carried out on a four-ball friction machine, a special device from WAGNER, on friction machines 2070 SMT-1M and MTU. Bench-in run was carried out on the D-240 engine and gearbox of a mobile drilling rig. The crushed solid waste of the agro-industrial complex was used as adsorbents for organic wastewater pollution. Their joint processing was carried out under hydrothermal supercritical conditions. (Results and discussion) It has been shown that nanostructure boehmite has antifriction, antiwear and extreme pressure properties. The possibility of its use as a product for running of a diesel engine has been found. The application of the boehmite in oils accelerates the running-in of a diesel engine, provides savings in material, labor and energy resources. For running-in of power transmission units, an additive containing bemite, surfactant, talc and kaolin reduced the running-in time of the drilling rig gearbox by 2.5 times. The article shows that the crushed plant waste of the agro-industrial complex, such as buckwheat husk, rice, and sunflower can be effectively used as adsorbents for the localization of pollution and wastewater treatment of agricultural enterprises. Subsequent processing of the adsorbent saturated with organic matter under hydrothermal supercritical conditions ensures the complete processing of organic substances to produce purified water and a high-enthalpy vapor-gas mixture or combustible gases, depending on the processing conditions. (Conclusions) Energy-saving technologies for the technical service of a diesel engine and transmission units can be based on the use of tribotechnical materials containing nanostructure boehmite. Technological solutions for energy-saving technologies for processing solid and liquid organic waste can consist in adsorption wastewater treatment followed by hydrothermal treatment in supercritical conditions.