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Wyszukujesz frazę "deacetylation" wg kryterium: Temat


Wyświetlanie 1-3 z 3
Tytuł:
The influence of chitosan flake deacetylation degree on orthophosphate sorption efficiency from aqueous solutions
Autorzy:
Bugajska, Paula
Filipkowska, Urszula
Jóźwiak, Tomasz
Kuczajowska-Zadrożna, Małgorzata
Powiązania:
https://bibliotekanauki.pl/articles/1034433.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Tematy:
chitosan
deacetylation degree
orthophosphate
sorption
Opis:
The article presents the effectiveness of orthophosphate sorption from aqueous solutions depending on the deacetylation degree of chitosan flakes. The first stage of the research was to determine the pH value at which the sorption process was the most effective (from the pH range 2–11). In the second stage, research was carried out to determine the maximum sorption capacities of chitosan with deacetylation degrees of 75%, 85% and 90% in relation to PO43-. The highest effectiveness of orthophosphate removal on chitosan, regardless of its deacetylation degree, was obtained at pH 4. At pH 2 and 3, the chitosan flakes dissolved. This study showed that the sorption effectiveness of phosphorus compounds depends on the deacetylation degree of chitosan. Along with the increase in deacetylation degree, the sorption capacity of chitosan also increases in relation to orthophosphates. It is related to the higher number of amino groups in the structure of chitosan, which are responsible for the sorption of pollutants in the form of anions. The maximum sorption capacity of chitosan-DD = 75% in relation to biogen was 5.13 mg/g, chitosan-DD = 85% was 5.65 mg/g, and chitosan-DD = 90% was 5.91 mg/g. After 60 minutes, the desorption process had begun and was most likely caused by an increase in the pH of the solution. Due to chitosan's ability to neutralise the sample and the associated risk of desorption, the time of sorbent contact with sewage cannot be longer than 60 minutes.
Źródło:
Progress on Chemistry and Application of Chitin and its Derivatives; 2018, 23; 33-44
1896-5644
Pojawia się w:
Progress on Chemistry and Application of Chitin and its Derivatives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of the deacetylation degree of chitosan in the form of flakes on the effectiveness of nitrates v sorption from aqueous solutions
Autorzy:
Jóźwiak, Tomasz
Filipkowska, Urszula
Bugajska, Paula
Kuczajowska-Zadrożna, Małgorzata
Mielcarek, Artur
Powiązania:
https://bibliotekanauki.pl/articles/1034527.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Tematy:
chitosan
deacetylation degree
nitrate
sorption
Opis:
The influence of the degree of deacetylation of chitosan from the range of DD = 75–90% on the effectiveness of sorption of nitrates from aqueous solutions was investigated. The scope of the research included: determining the effect of pH on the effectiveness of N-NO3 binding on chitosan sorbents and determining the sorption capacity of chitosan sorbents with different degrees of deacetylation after 5, 15, 30 and 60 minutes. The effectiveness of sorption of nitrates on chitosan sorbents increased in the series DD=75% < DD=85% < DD=90%. Regardless of the degree of deacetylation, the sorption effectiveness of nitrates on chitosan was the highest at pH 4. The amount of nitrate-related sorbents was the highest after 30 min of sorption. A process time which was too long resulted in desorption of nitrates. The maximum sorption capacity for chitosan with the degree of deacetylation DD = 75, 85 and 90% was 0.59 mg N-NO3/g, 0.60 mg N-NO3/g and 0.87 mg N-NO3/g, respectively.
Źródło:
Progress on Chemistry and Application of Chitin and its Derivatives; 2018, 23; 88-96
1896-5644
Pojawia się w:
Progress on Chemistry and Application of Chitin and its Derivatives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of chitosan deacetylation degree on reactive black 5 sorption efficiency from aqueous solutions
Autorzy:
Jóźwiak, Tomasz
Filipkowska, Urszula
Szymczyk, Paula
Kuczajowska-Zadrożna, Małgorzata
Mielcarek, Artur
Zyśk, Michał
Powiązania:
https://bibliotekanauki.pl/articles/1034679.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Tematy:
Reactive Black 5
chitosan
deacetylation degree
sorption
Opis:
In the paper sorption capacity of chitosan having a deacetylation degree DD=75%, DD=85% and DD=90% relatively to the Reactive Black 5 were compared. Studies on the effectiveness of the dye sorption were carried out in a wide pH range – from 3 to 11. For each of the tested chitosan sorbents, sorption capacity has been determined. The results were described by isotherms Freundlich and Lagmuir isotherms, and a double Langmuir isotherm. Sorption of Reactive Black 5 most efficiently occurred at pH 4. At pH <4 chitosan sorbents underwent dissolution, regardless of the degree of deacetylation. The efficiency of dye sorption increased with the degree of deacetylation. The sorption capacity calculated after 12 h of the chitosan sorption with DD=75%, DD=85% and DD =90% was, relatively to the Reactive Black 5, respectively 433.03 mg/g and 464.52 mg/g and 532.14 mg/g. The impact of the deacetylation degree on pHZPC (zero point of charge) of the sorbent was also examined. Along with the increase in the deacetylation degree the value of chitosan pHZPC increased as well and at DD=75% DD=85% and DD=90%, pHZPC amounted respectively 7.6, 7.7 and 7.8.
Źródło:
Progress on Chemistry and Application of Chitin and its Derivatives; 2016, 21; 83-92
1896-5644
Pojawia się w:
Progress on Chemistry and Application of Chitin and its Derivatives
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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