CC BY
21
AZERBAIJAN CHEMICAL JOURNAL № 2 2023 ISSN 2522-1841 (Online)
!SSN 0005-2531 (Print)
UDC 544.23.02/.03
STUDY OF SORBSION PROPERTIES OF COPPER (II) ION WITH CHITOSAN
BASED SORBENT
S.M.Mammadova, A.R.Rajabli, N.T.Rahimli, H.F.Aslanova, Ch.M.Seyidova, C.E.Guliyeva, N.A.Zeynalov, D.B.Tagiyev
M.Nagiyev Institute of Catalysis and Inorganic Chemistry, Ministry of Science and Education
of the Republic of Azerbaijan
Samira_m@mail.ru
Received 16.09.2022 Accepted 21.12.2022
Over the past few decades, a significant increase in the use of heavy metals has led to an increase in the amount of metals in the aquatic environment. For living organisms, among heavy metals, copper (II) is one of the toxic metals and one of the most common environment poUutants. Excessive concentrations of Cu2+ ions can cause various diseases and intoxications in humans. In this regard, the use of absorbents for the sorption of metak is both an economicaUy and technologically efficient method. Quaternized natural polymer chitosan was used as a sorbent to study the sorption properties of copper (II) ion. During the research, the optimal conditions of the sorption process was determined, pH effect of the environment, initial concentration of the metal on the sorption process were studied. The sorption capacity of the synthesized sorbent towards the Cu (II) ion was studied and it was determined that the maximum sorption capacity equal to 255 mg/g was at pH=4. Moreover the influence of copper (II) ion concentration on the sorption process was studied. It was found that the sorption capacity and sorption degree of the sorbent increase with an increase in the concentration of the Cu2+ ion in the solution. It was determined that the maximum sorption capacity was 406 mg /g, which corresponds to the concentration of copper (II) ion, equal to 10-10-2 mol/L. The results show that quaternized chitosan-based sorbent can be successfully used for the sorption of Cu (II) ion.
Keywords: chitosan, sorbent, quaternization, sorbtion capacity, sorbtion degree.
doi.org/10.32737/0005-2531-2023-2-6-12 Introduction
The use of absorbents for the sorption of metals is both an economically and technologically effective method. However, adsorption methods have the ability to effectively remove heavy metals at very low concentrations (1-100 mg/l). Various adsorbents have been reported in the literature for this purpose, including, to a lesser extent, the use of hydrogel adsorbents for heavy metal removal in aqueous phase. Here we will provide information on the design, application and effectiveness of hydro-gel systems as adsorbents [1].
Natural polymers, especially polysaccha-rides such as chitin and its derivative chitosan, are attracting great attention as an effective adsorbent for many ions in industrial waste water. Chitosan has a high content of amino and hydroxyl functional groups which are essential for the adsorption and removal of aquatic pollutants [2]. The choice of chitosan as the adsorbent was due to its remarkable physico-
chemical characteristics, chemical stability, high reactivity, excellent chelation behaviour and high selectivity toward many aquatic pollutants [3-8]. Although chitin can be used as biosorbent whose cost is lower than chitosan, the capacity of chitosan is five or six times greater than that of chitin due to its free amino and hydroxyl groups [9]. Moreover, chitosan is well-known for its unique properties, such as biodegradability, hydrophilicity, non-toxicity, and adsorption capacity [10]. Among a variety of raw materials, chitosan has attracted special attention by researchers because of two major merits: its low cost, which is related to it being the second most abundant polysaccharide in the world after cellulose and its outstanding adsorption behavior, especially for metal ions [11]. The unique properties of chitosan as an adsorbent are due to its structural and chemical properties. Therefore, in order to gain a broad knowledge of these properties, it is necessary to study the adsorption nature of chitosan with different adsorbates.
The tremendous increase in the use of heavy metals over the past few decades has inevitably resulted in an increased flux of metallic substance in aquatic environment. Industrial wastewater contains higher amount of heavy metals that can pollute the water when it is discharged to the nature. Toxic heavy metals of particular concern in treatment of industrial wastewaters include zinc, copper, nickel, mercury, cadmium, lead and chromium. Heavy metals are the elements that have more than 5 times the specific gravity than that of water. Heavy metals are one of the most toxic types of water pollutants. At least 20 metals are considered to be toxic and approximately half of these metals are emitted to the environment in quantities that are risky to the surroundings, additionally to the human health [12]. Heavy metal contamination of water sources is hazardous to plants, animals and microorganism and can be carcinogenic to mankind [13, 14].
Copper is regarded as one of the most basic toxic metals. The increase levels of copper in environment are posing a serious threat to mankind. It can cause harmful biochemical effects, toxicity and hazardous disease in human beings [15]. Excessive concentrations of Cu2+ ions can cause harmful biochemical effects and toxicity in humans. Copper can enter the body through air, water and food and cause dangerous diseases [16].
Adsorption is established as the most effective method for water decontamination applications and analytical separation purposes. It offers advantages over the other options such as simplicity in terms of design and operation, uses less chemicals, requires low initial costs and can remove different types of pollutants [17-19]. The use of absorbents for the sorption of metals is both an economically and technologically effective method.
Different pH solutions for copper sorption have been prepared in the laboratory. Solutions
for copper sorption were developed in the laboratory. Effect of parameter like pH, adsorbent dose, contact time, temperature and initial metal ion concentration were also determined. The optimum conditions obtained were 360 min contact time, 200 mg adsorbent dose and pH 5 for copper and 180 min contact time, 200 mg adsorbent dose and pH-7 for zinc. The maximum adsorption capacity was found to be 89% for copper and 96.97% for zinc [12].
In another study, the sorption of Cu(II) particle from aqueous solution onto chitosan and cross-linked chitosan-bentonite (CTS-BTN) as adsorbent were conducted in batch conditions. The effect of different test parameters: starting pH, sorption time was assessed. Chitosan and CTS-BTN showed an adsorption capacity of 125 mg/g and 142.86 mg/g, respectively [20].
In the presented research, chitosan-based sorbents was obtained and the sorption capacity of copper (II) ion in different pH environments was determined.
Experimental part
Chitosan (Cs) average molecular weight 100-300 kDa, NaBH (chemically pure >96%), acetic acid (Glacial), ethanol (95%), benzyl chloride (chemically pure 99.5%), 8-oxo-quinoline (C9H7NO) average molecular weight 145.16 g/mol (is a chelating agent used to quantify metal ions), copper sulphate pentahydrate (molecular weight 250 g/mol) NH4OH, CH3COOH used for buffer solutions are chemically pure, from Sigma Aldrich.
Preparation of solutions for sorption
During the research, 3 10-2 M solution of copper metal was used. For this purpose, 3 10-2 M solution of CuSO4 5H2O salt was prepared by dissolving the calculated mass of this salt in a solution of distilled water. 0.75 g of CuSO4 5H2O salt is diluted it with distilled water in
Fig. 1. Structure of chitosan.
100 ml flask. 8-Oxo-quinoline solution with a concentration of 3 10-2 M was used as a reagent for the sorption of copper ions. To prepare a reagent solution with a concentration of 3 10-2 M, 0.435 g of the given reagent was diluted with alcohol in 100 ml flask.
Preparation of buffer solutions
To prepare buffer solutions, pH=3 and pH=11 solutions was prepared first. To adjust the pH=3 environment, 5.6 ml of CH3COOH was diluted to the mark in 1000 ml flask with distilled water according to the methodology. Also pH=4, 5, 7, 9, 10, 11 buffer solutions was prepared [21, 22].
Study of the dependence of metal concentration on pH and Xmax
2 types of solution are prepared. 2 ml of reagent solution and 1 ml of Cu (II) solution added to a 25 ml flask and diluted to the line with appropriate pH solutions (pH=3, 5, 7, 9, 11). Then 2 ml of the reagent added to a 25 ml flask and diluted with appropriate pH solutions (pH=3, 5, 7, 9, 11). The optical densities of each of the 5 solutions are measured at wavelengths of 380, 400, 440, 470, 490, 510, 530, 560, 610 nm.
Adsorption experiments
To determine the sorption of copper (II) ion, 30 mg of sorbent, copper solution and 18 ml of pH (3, 4, 7, 9, 10) solutions added to each 5 flasks, and keep for 1 day. After 24 hours, 1 ml of aliquot and 2.5 ml of reagent solution were added to 20 ml flasks and were diluted with pH=3, 4, 7, 9, 10 respectively. To prepare the background solution, 2.5 ml of reactive solution diluted with pH=3.
Dependence of sorption on the concentration of copper ions
To study the dependence of sorption on the concentration of copper ion, 30 mg of sorbents added to each 5 flasks. Appropriate amounts of copper solutions (1.33 ml, 2.6 ml, 5.3 ml, 6.6 ml, 13.3 ml) added to 20 ml flasks and each is diluted with pH=7 and added to the sorbents. It is stored for 1 day. To prepare the background solution, 2.5 ml of reagent added to
a 25 ml flask and complete with pH=7 to the outline. Measurements are made after 1 day.
Results and discussions
The interaction between biosorbents and biosorbates depends on the biosorbates, their chemical composition, chemical and physical nature, the pH of the solution and other components in the system.
Optical densities were first determined on a KFK-3 photocalorimeter to establish a degree graph for copper sorption. The optical densities of each of the solutions given in the experimental part at wavelengths of 380, 400, 440, 470, 490, 510, 530, 560, 610 nm were measured. The dependence of the concentration of copper (II) ion on pH and Xmax is given in the graph below.
Graph of dependence of the concentration of copper (II) ion on pH and Xmax.
As can be seen from Figure, the optimal wavelength is Xmax=380 nm and the optimal pH is 3.
Optical densities were determined with reactive solutions of different concentrations and the results obtained are given in the Table below.
Table 1. Values of optical density as a function of
Vr, ml 1 1.5 2 2.5
AA 0.01 1.05 0.6 1.9
Then the dependence of the concentration of Cu (II) ion on the density was studied and a graph was plotted. The values of optical
densities in copper solutions of different concentrations are given in Table 2.
Table 2. Values of optical densities of metal solutions of different concentrations CCu2+= 3 10-2M, CR = 3 10-2M,
Vme, ml 0.2 0.4 0.6 1 1.4
AA 0.08 0.34 0.5 0.515 0.27
It is known that the state of metal ions in solution varies depending on the pH value. Also, depending on the pH, the ratio of the number of ionized and non-ionized functional groups in macromolecules varies. Thus, in each case, the sorption of the metal ion by the sorbent passes through the maximum in a certain range of the value of the pH of the liquid phase.
To determine the optimal pH of the sorption, 5 beakers of the same capacity and shape are taken. The same amount of sorbent (quaternized Cs) is added to each beaker. The concentration of sorbed copper ion in each beaker and the total volume of the liquid phase are kept constant. The variable parameter becomes only the pH of the medium (pH=3, 5, 7, 9, 11). After one day, the equilibrium concentration of the metal ion is determined by the method of photometric analysis (according to the graded graphic). Prices are given in the Table below.
pH 3 4 7 9 10
AA 0.125 0.055 0.03 0.045 0.04
As shown in Table 3 the optimum pH was-3, calculations are made based on these
results. It is known that the main factor influencing the sorption of organic and inorganic ions by the adsorbent from aqueous solutions is the pH of the medium. Because the H+ and OH- ions in the solution cause the adsorbent, surface and volume to become charged, ie ionized, which directly affects the sorption rate and sorption capacity of the sorbate [23, 24]. In this regard, copper (II) ion were sorbed with Cs sorbent at different pH, sorption capacity (SC) and sorption degree (SD) were calculated according to the following formula (1), (2). The obtained values are given in Table 4 [25, 26].
Co,x10-2mol/l - the concentration of the used copper (II) ion; C initial mq/l - the initial concentration of the copper (II) ion; C final mq/l - the final concentration of the copper (II) ion; Cabsorbed mq/l - the absorbed concentration of the copper (II) ion; SC mq/q - sorption capacity SD, % - sorption degree; Valik, ml -the amount of solution we carried out measurements; A -optical density Vdeggraf, ml - the volume of copper ion corresponding to the value of the optical density in the graded graph
(1)
SC = Cinit Cfin x V
SD =
a
Qnit-Cfin Cinit
x 100
(2)
Here, Cinitial is the concentration of Cu (II) ion before sorption, Cfinal is the concentration of Cu (II) ion after sorbtion, V-is the total volume of the adsorbed solution (ml), and g is the milligram of the sorbent taken for sorption. g = 30 mg are taken.
Table 4. Sorption rate and sorption capacity pH-dependence values of copper (II) ion with chitosan-based sorbent
msorb=30 mq, VT=20 ml, CMe=3 10-2 M.
pH 3 4 7 9 10
C o,x10-2mol/l 3 3 3 3 3
Cinitial mq/l 3.84 3.84 3.84 3.84 3.84
C final mq/l 0.10 0.015 0.384 - -
C absorbed mq/l 3.751 3.825 3.456 - -
SC mq/q 214 255 230 - -
SD,% 97.3 99.6 90 - -
Val^ml 1 1 1 1 1
A 0.055 0.125 0.09 0.045 0.04
Vdeg.graf,ml 0.23 - 0.12 - -
As can be seen from Table 4, the values of ST and SD were low at pH = 3, and the highest values at pH = 4 were 255 mg/g and 99.6%, respectively. Protonation of active functional groups in hydrogel occurs in acidic medium (pH<4). As the pH of the medium changes to alkali, the surface of the hydrogel
becomes deprotonation, and, conversely, the negative charging causes in easy sorbtion of copper (II) ion.
The sorption process in the solution of copper (II) ion with Cs-based sorbent is schematically shown in below.
Cifll soil»» CMoun bWKK in Uilouo beadt n
Cufl' stuoi CU! soMkr
DflfOT« *)S0rS»0n Ato MltûrpbOn
Scheme. The adsorption process of chitosan-based sorbent.
In addition, the effect of the concentration of metal ions on the sorption process was studied. Sorption of metal ions by insoluble solid sorbents is associated with the formation of equilibrium in a heterogeneous system. It is clear that the formation of this equilibrium depends on the initial concentration of the metal ion [27, 28]. To determine this dependence in practice, static sorption experiments were performed without changing the total volume of the liquid phase at the optimal pH of the metal ion. Based on
the obtained results, sorption capacity of sorbent was determined at what concentration of metal ion is maximum. The values obtained from the results are given in Table 5.
As can be seen from Table 5, the sorption capacity and sorption degree of the sorbent increase as the concentration of Cu2+ ions in the solution increases. As can be seen from the Table, the maximum sorption capacity was 406 mg/g. This corresponds to the value of the metal concentration of 10 10-2 mol/l.
Table 5. Sorption capacity and sorption degree of metal solutions of different concentrations with chitozan based sorbent msorb=30 mg, Vt=20 ml, CMe=3^10-2 M, pH = 7_
Cme x10-2mol/l 2 4 8 10 20
Co, x 10-2mol/l 3 3 3 3 3
Cinitial mq/l 2.56 5.12 5.24 0.769 0.04
Cfinal, mq/l 0.2 0.092 0.12 0.16 -
C absorbed mq/l 2.36 5.028 5.12 0.609 -
SC mq/q 157 335 341 406 -
SD,% 92.1 98.2 98.7 99.1 -
Valik,ml 3 2 2,5 2 2
A 0.1 0.09 0.1 0.12 0.05
^e^raf ml 0.22 0.21 0.22 0.21 -
References
1. Muya F.N., Sunday C.E., Baker P., Iwuoha E. Environmental remediation of heavy metal ions from aqueous solution through hydrogel adsorption: A critical review. Water Sci Technol. 2016. V. 73. No 5. P. 983-992.
2. Bhatnagar A., Sillanpaa M. Applications of chitin-and chitosan-derivatives for the detoxification of water and wastewater - A short review. Advances in Colloid and Interface Science. 2009. V. 152. P. 26-38.
3. Ravi M.N.V. Characterization and Biodegradation Studies for Interpenetrating Polymeric Network (IPN) of Chitosan-Amino Acid Beads. React Funct Polym. 2000. V. 46. P. 1-27.
4. Guibal E. Interactions of metal ions with chitosan-based sorbents: a review. Sep Purif Technol. 2004. V. 38. P. 43-74.
5. Varma A.J., Deshpande S.V., Kennedy J.F. Anodic Stripping Voltammetric Determination of Nitrite Using Carbon Paste Electrode Modified with Chitosan. Carbohydr Polym. 2004. V. 55. P. 77.
6. Gerente C., Lee V.K.C., Cloirec P.L., McKay G. Application of Chitosan for the Removal of Metals From Wastewaters by Adsorption -Mechanisms and Models Review. Crit Rev Environ. Sci Technol. 2007. V. 37. P. 41-127.
7. Crini G., Badot P.M. Application of Chitosin, a natural aminopolysaccharide, for dye removal from aqueous solution by adsorption processusing batch studies: A Review of Recent Literature. Prog. Polym. Sci. 2008. V. 33. P. 399.
8. Aneesh P., Jishna M. Adsorption of Nitrates Using Quaternized Chitosan Resin. J. Chemical Engineering Processes Technoogy. 2017. V. 8. P. 2-7.
9. Bailey S.E., Olin T.J., Bricka R.M., Adrian D.D. A review of potentially low-cost sorbents for heavy metals. Water research. 1999. V. 33. No 11. P. 2469-2479.
10. Ngah W.W., Teong L., Hanafiah M. Adsorption of dyes and heavy metal ions by chitosan composites: A review. Carbohydrate Polymers. 2011. V. 83. No 4. P. 1446-1456.
11. Peter M.G. Applications and environmental aspects of chitin and chitosan. J. Macromolecular Science, Part A: Pure and Applied Chemistry. 1995. V. 32. No 4. P. 629-640.
12. Jain G. Removal of copper and zinc from waste water using chitosan. 2013. P. 58.
13. Boddu V.M., Abburi K., Randolph A.J., Smith E.D. Separation Science and Technology. 2008. V. 43. P. 1365-1381.
14. Francisco C.F., Barros F.C.F., Sousa F.W., Cavalcante R.M., Carvalho T.V., Dias F.S., Queiroz D.C., Vasconcellos L.C.G., Nascimento R.F. Clean. 2008. V. 36. P. 292-298.
15. Gustavo R., et al. Enhanced copper release from pipes by alternating stagnation and flow events. Env. Sci Tech. 2007. V. 41. P. 7430-7436.
16. Krishnamurthy C.R., Vishwanathan P. Toxic metals in the Indian environment. Tata Mc Grew Hill Publishing Company Ltd. 1991. P. 188.
17. Fu F., Wang Q. Removal of heavy metal ions from wastewaters: A review. J. Environmental Management. 2011. V. 92. No 3. P. 407-418.
18. Bhatnagar A., Minocha A.K. Conventional and non-conventional adsorbents for removal of pollutants from water-a review. Indian J. Chemical Technology. 2006. V. 13. No 3. P. 203-217.
19. Sutirman Z.A., Sanagi M.M., Karim K.J.A, Naim A.A.,.Ibrahim W.A.W. Chitosan-Based Adsorbents For The Removal Of Metal Ions From Aqueous Solutions. Malaysian J. Analytical Sciences. 2018. V. 22. P. 839 - 850.
20. Hargono H., Sarah A.M., Nevrita F., Jos B. Kinetics and Equilibriums Adsorption of Cu (II) Ion by Chitosan and Cross-Linked Chitosan-Ben-tonite. Reaktor. 2019. V. 19. No 3. P. 117-124.
21. Shemshadi R.Sh., Zeynalov N.A., Tapdigov Sh.Z., Arvand M., Latify L. Removal of Cadmium (II) by Natural absorbents. Chemical Problems. 2009. No 3. P. 586-589.
22. Arvand M., Shemshadi R.Sh., Efendiev A.A., Zeynalov N.A., Latify A., Pourhabib A., Farnoosh R. Comparative Study for the Removal of Hg (II) From Aqueous Solutions by Adsorption on The Gum Arabic and Modified Gum Arabic. Asian J. Chemistry. 2010. V. 22. No 8. P. 6289-6301.
23. Mammadova S.M., Tapdigov Sh.Z., Humbatova S.F., Zeynalov N.A., Guliyeva A.R., Gasimov E.M. Recearch Into Sorbtion Properties and Structures of Polymer Hydrogel Immobilized by Doxorubicin. Chemical Problems. 2018. V. 16. No 3. P. 316-322.
24. Shemshadi R.Sh., Zeynalov N.A., Tapdigov Sh.Z., Arvand M., Latify L. Removal of Mercury (II) Cations by Natural Absorbents. Azerb. Chem. J. 2010. No1. P. 53-56.
25. Mammadova S.M., Tapdigov Sh.Z., Tagiyev D.T., Zeynalov N.A. Investigation Chem. Interaction Type of Polyacrylic Acid Based Hydrogel with Doxorubicin Hydrochloride. American Chem. Science J. 2016. V. 12. No 2. P. 1-9.
26. Shemshadi R.Sh., Zeynalov N.A., Tapdigov Sh.Z., Arvand M., Latify L. Removal of Cadmium (II) by Natural Natural Absorbent Tragacanth Gum. Azerb. Chemical J. 2010. No 2. P. 51-54.
27. Shemshadi R.Sh., Zeynalov N.A., Tapdigov Sh.Z., Amanov E.B., Arvand M. Study of Hg (II) adsorbtion from aqueous solutions on the synthetic polymers. Azerb.Chem. J. 2010. No 3. P. 51-55.
28. Arvand M., Shemshadi R.Sh., Efendiev A.A., Zeynalov N.A. Synthetic polymers as Adsorbents for the Removal of Cd (II) from Aqueous Solutions. Asian J. Chemistry. 2011. V. 23. No 6. P. 2445-2448.
XÍTOZAN OSASLI SORBENTLO MÍS (II) ÍONUNUN SORBSÍYA XÜSUSÍYYOTLaRÍNÍN
óyronílmosí
S.M.Mammadova, A.R.Rac3bli, N.T.Rahimli, H.F.Aslanova, Ç.M.Seyidova, C.E.Quliyeva, D.B.Tagiyev,
N.A.Zeynalov
Son bir neça onillikda agir metallann istifadasindaki bôyûk artim, su mûhitinda metallann miqdannin artmasina sabab olmuçdur. Agir metallar arasinda mis (II) canli orqanizmlar ûçûn an çox toksiki metallardan biri sayilir va atraf mühitin daha geniç yayilmiç agir metal çirklandiricilarindan biridir. Cu2+ ionunun qatiliginin haddan artiq olmasi insanlarda müxtalif xastaliklara, toksikliya sabab ola bilar. Bu baximdan metallarin sorbsiyasi ûçûn absorbentlarin istifadasi ham iqtisadi, ham da texnoloji cahatdan effektiv bir ûsuldur. Mis (II) ionunun sorbsiya xassalarinin ôyranilmasi ûçûn sorbent kimi kvaterniza olunmuç tabii polimer xitozandan istifada edilmiçdir. Tadqiqat zamani sorbsiya prosesinin optimal çaraitlari mûayyan edilmiç, sorbsiya prosesina mûhitin pH-nin, metalin baçlangic qatiliginin tasiri ôyranilmiçdir. Sintez olunmuç sorbentla Cu (II) ionunun sorbsiya tutumu ôyranilmiç va mûayyan olunmuçdur ki, an yûksak sorbsiya tutumu pH=4-da 255 mq/q olmuçdur. Bundan baçqa, sorbsiya prosesina mis (II) ionunun qatiliginin tasiri ôyranilmiçdir. Gôstarilmiçdir ki, mahlulda Cu2+ ionunun qatiligi artdiqca sorbentin sorbsiya tutumu va sorbsiya daracasi artir. Mûayyan olunmuçdur ki, maksimum sorbsiya tutumu 406 mq/q olmuçdur, bu da mis (II) ionunun 10^10-2 mol/l qatiliginin qiymatina uygun galir. Alinmiç naticalar onu gôstarir ki, kvarterniza olunmuç xitozan sorbentini Cu (II) ionunun sorbsiyasi ûçûn ugurla tatbiq etmak olar.
Açar sozlzr: xitozan, kvaterniza, sorbent, sorbsiya tutumu, sorbsiya daracasi.
ИЗУЧЕНИЕ СОРБЦИОННЫХ ХАРАКТЕРИСТИК ИОНА МЕДИ (II) СОРБЕНТОМ НА ОСНОВЕ
ХИТОЗАНА
С.М.Мамедова, А.Р.Раджабли, Н.Т.Рагимли, Г.Ф.Асланова, Ч.М.Сеидова, Дж.Э.Кулиева, Д.Б.Тагиев,
Н.А.Зейналов
За последние несколько десятилетий значительный рост употребления тяжелых металлов привел к увеличению количества металлов в водной среде. Для живых организмов среди тяжелых металлов медь (II) является одним из токсичных металлов и одним из наиболее распространенных загрязнителей окружающей среды. Чрезмерные концентрации иона Cu2+ могут вызывать у человека различные заболевания и интоксикации. В связи с этим применение абсорбентов для сорбции металлов является как экономически, так и технологически эффективным методом. Для изучения сорбционных свойств иона меди (II) в качестве сорбента использовали кватернизированный природный полимер хитозан. В ходе исследований были определены оптимальные условия сорбционного процесса, изучено влияние рН среды, исходной концентрации металла на сорбционный процесс. Изучена сорбционная емкость синтезированного сорбента по отношению к иону Cu (II) и было определено, что максимальная сорбционная емкость составляет 255 мг/г при рН=4. Кроме того, было изучено влияние концентрации иона меди (II) на процесс сорбции. Было установлено, что сорбционная емкость и степень сорбции сорбента увеличиваются с увеличением концентрации иона Cu2+ в растворе. Было установлено, что максимальная сорбционная емкость составила 406 мг/г, что соответствует концентрации иона меди (II), равной 10-10-2 моль/л. Полученные результаты показывают, что сорбент на основе кватернизованного хитозана можно успешно использовать для сорбции иона Cu (II).
Ключевые слова: хитозан, кватернизация, сорбент, сорбционная емкость, степень сорбции.
