2021

Постійне посилання на фонд

https://ela.kpi.ua/handle/123456789/53784

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Перегляд 2021 за Ключові слова "adsorption"

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  • Ескіз
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    Adsorption of 4-chlorphenol by brown coal activated by potassium hydroxide
    (КПІ ім. Ігоря Сікорського; ТОВ «Українська водна спілка», 2021) Таmarkina, Yu. V.; Frolova, I. B.; Кucherenko, V. O.
    The purpose of the work is to evaluate the 4-chlorophenol (CP) adsorption capacity of brown coal activated carbons (ACs) prepared at different temperature of KOH activation. ACs were obtained in three stages: 1) impregnation of coal with a KOH solution, 2) heating (4 deg/min) in argon to a given temperature t (400-800C) and exposure for 1 h, 3) cooling, washing from KOH, drying. The samples are designated as AC(t). Based on the N2 adsorption-desorption isotherms, the ACs total pore volume (Vt, cm3 /g) and specific surface area (S, m2 /g) were determined. The ACs adsorption capacities were measured at 25С, CP concentration 700 mg/L, АC dosage – 1 g/L. The alkaline activation temperature was found to be a key factor in forming porosity of ACs and ability to adsorb CP. The CP maximum capacity (ACP(m), mg/g) increases 6.6 times up to 307 mg/g for AC(800) having S=1142 m2 /g. The specific adsorption capacity (ACP(S) = ACP(m)/S, mg/m2 ) sharply decreases in a sample range from AC(400) to AC(550) and weakly depends on temperature at 550-800C. The kinetics of CP adsorption is best described by a pseudo-second order model. The rate determining stage is the interaction of CP molecules with AC surface. The CP adsorption isotherms are best described by the Langmuir model. The dependence of the ACP(m) from S can be approximated by three linear equations that probably correspond to the three regions of forming surface adsorbtion centers (AdCs). The first (S370 m2 /g) is characterized by a small adsorption capacity increment (kS=0.103 mg/m2 ), but a significant (16.4 times) decrease in the specific capacity ACP(S). In the second region (S=370-770 m2 /g, t=550-750C), capacity increment is 10 times more (kS=0.985 mg/m2 ) and in the third region (S770 m2 /g, t750C) the increase in CP capacity is the smallest (kS=0.067 mg/m2 ). The thermoinitiated formation of AdCs is assumed to be not proportional to the increase in surface area, and their chemical structure and reactivity is determined by the alkaline activation temperature.
  • Ескіз
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    Removal of beryllium (Be2+) from water samples by sorption process: a review
    (КПІ ім. Ігоря Сікорського; ТОВ «Українська водна спілка», 2021) Arar, Ö.
    Beryllium (Be2+) is an important industrial metal because of its unusual material properties: it is lighter than aluminium and six times stronger than steel. Beryllium is a strategic metal due to its low density combined with its strength, low neutron absorption, high melting point and high modulus of elasticity. Beryllium is often alloyed with other metals such as copper and is an important component of materials used in the aerospace, automotive, energy, defense, medical, and electronics industries. However, beryllium and its compounds are very toxic, especially to the lungs, skin, and eyes. Beryllium compounds are known carcinogens based on sufficient evidence of carcinogenicity in humans from human studies. Toxic effects of beryllium include immunotoxic, allergic, mutagenic, and carcinogenic effects. Mammalian tissues do not excrete it, so the effects are cumulative and can lead to death at high concentrations. Therefore, removal of Be2+ is important. In this review, the removal of Be2+ from water samples by sorption processes using different sorbents was summarized. The effects of process parameters on the removal of Be2+ have been summarized. The work discussed showed that ion exchange resins, various modified biosorbents metal oxides can be used for the removal of Be2+. The results showed that the pH of the solution has an important effect on the removal rate. Sorption kinetics vary from 3 minutes to 48h. When the functional groups are on the surface of the sorbent, the sorption process is rapid. However, if the surface of the sorbent is covered with oxides such as magnetite, it takes longer to reach equilibrium. Published work shows that more than 99 % of Be2+ can be removed from solution.
  • Ескіз
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    The study of the sorption properties of filtering materials based on titanium phosphate – porous titanium composition
    (КПІ ім. Ігоря Сікорського; ТОВ «Українська водна спілка», 2021) Shablovski, V. A.; Tuchkoskaya, А. V.; Rukhlya, V. А.; Pap, О. G.; Kudelko, K. О.
    Inorganic sorbents are more selective in comparison with commercial ion exchange resins towards of metal ions. However, inorganic sorbents characterized not high kinetic properties. One of the way to increase the kinetic rate of inorganic sorbents is to reduce the particle size of these materials, other way is synthesizing inorganic sorbents as porous products from powder materials. A sample of such inorganic sorbents is titanium phosphate of various compositions. Studying the properties of microfilters based on composition titanium phosphate - porous titanium has been developed. The sorbents based on acidic titanium phosphate Ti(HPO4)2-H2O were used for filtering solution with Fe(II) content. It is found that the number of impregnations with inorganic sorbent modificator is important and influence filtration process. The obtained results demonstrated that after the first impregnation of porous material with a smaller pore size, it is possible to obtain such sorbent as a mass content of powder material. By varying the ionic form of titanium phosphate, the porosity of titanium, the amount of impregnation, it could be possible effect on the sorption Fe(II). The sorption properties of titanium-titanium phosphate microfilters were studied by potentiometric titration in the NaCl-NaOH system, as well as the sorption of Fe2+ ions. The degree of purification for Fe(II) from solution with a concentration of 10 mg/l is 64 %. Application an electric potential to the microfilter of porous titanium - phosphate titanium increases the degree of purification of Fe(II) to 88 %.