Oxidation of arsenite in aqueous solutions by redox copolymer with N-bromosulfonamide functional groups

2013 ◽  
Vol 73 (1) ◽  
pp. 108-113 ◽  
Author(s):  
Daniel Ociński ◽  
Ewa Stanisławska ◽  
Elżbieta Kociołek-Balawejder
1992 ◽  
Vol 57 (7) ◽  
pp. 1393-1404 ◽  
Author(s):  
Ladislav Svoboda ◽  
Jan Uhlíř ◽  
Zdeněk Uhlíř

The properties of Ostsorb DETA, a selective ion exchanger based on modified bead cellulose with chemically bonded diethylenetriamine functional groups, were studied, and its applicability to the preconcentration of trace amounts of lead from aqueous solutions was verified. The conditions of the preconcentration procedure in the column and batch modes were optimized for this purpose. The results obtained were applied to the determination of lead in phosphoric acid.


2021 ◽  
Vol 50 (39) ◽  
pp. 14009-14017
Author(s):  
Hai Wang ◽  
Renrong Liu ◽  
Huifang Wang ◽  
Baowei Hu ◽  
Muqing Qiu

The highly effective enrichment of U(vi) on COF/GO was attributed to a huge void ratio and a variety of oxygen-containing functional groups. It could be used as a promising candidate for environmental decontamination and energy storage.


2018 ◽  
Vol 5 (5) ◽  
pp. 172382 ◽  
Author(s):  
Wei Guo ◽  
Shujuan Wang ◽  
Yunkai Wang ◽  
Shaoyong Lu ◽  
Yue Gao

A magnetically modified rice husk biochar (MBC) was successfully prepared by a hydrothermal method from original biochar (BC) and subsequently used to remove phenanthrene (PHE) from aqueous solutions. The porosity, specific surface area and hydrophobicity of BC were significantly improved (approx. two times) after magnetic modification. The adsorption data fitted well to pseudo-second-order kinetic and Langmuir models. Compared with BC, MBC had a faster adsorption rate and higher adsorption capacity of PHE. The adsorption equilibrium for PHE on MBC was achieved within 1.0 h. The maximum adsorption capacity of PHE on MBC was 97.6 mg g −1 based on the analysis of the Sips model, which was significantly higher than that of other sources of BCs. The adsorption mechanism of the two BCs was mainly attributed to the action of surface functional groups and π–π-conjugated reactions. The adsorption of PHE on MBC mainly occurred in the functional groups of C–O and Fe 3 O 4 , but that on BC was mainly in the functional groups of –OH, N–H, C=C and C–O.


2020 ◽  
Vol 54 (1 (251)) ◽  
pp. 83-85
Author(s):  
M.L. Yeritsyan ◽  
K.M. Yeritsyan ◽  
V.M. Mavisakalyan ◽  
A.M. Arustamyan ◽  
R.P. Mkhitaryan

The reaction between urea and melamine was studied. The reaction resulted in tris-carbamide derivative of melamine. During the reaction between the melamine derivative and the glycoside group of chitosan the sim-triazine functional groups were formed, which are included in the structure of synthesized derivative of chitosan. The synthesized derivative of chitosan was tested. It is recommended to use this chitosan derivative as an absorbent for the separation of heavy metal ions such as Cd2+, Hg1+, Hg2+, Co2+, Ag1+, As3+, As5+, etc. from the aqueous solutions of salts.


2008 ◽  
Vol 74 (9) ◽  
pp. 2797-2804 ◽  
Author(s):  
Ernesto Micheletti ◽  
Sara Pereira ◽  
Francesca Mannelli ◽  
Pedro Moradas-Ferreira ◽  
Paula Tamagnini ◽  
...  

ABSTRACT The cyanobacterium Gloeothece sp. strain PCC 6909 and its sheathless mutant were tested for their abilities to remove copper ions from aqueous solutions, with the aim of defining the role of the various outermost polysaccharidic investments in the removal of the metal ions. Microscopy studies and chemical analyses revealed that, although the mutant does not possess a sheath, it releases large amounts of polysaccharidic material (released exocellular polysaccharides [RPS]) into the culture medium. The RPS of the wild type and the mutant are composed of the same 11 sugars, although they are present in different amounts, and the RPS of the mutant possesses a larger amount of acidic sugars and a smaller amount of deoxysugars than the wild type. Unexpectedly, whole cultures of the mutant were more effective in the removal of the heavy metal than the wild type (46.3 ± 3.1 and 26.7 ± 1.5 mg of Cu2+ removed per g of dry weight, respectively). Moreover, we demonstrated that the contribution of the sheath to the metal-removal capacity of the wild type is scarce and that the RPS of the mutant is more efficient in removing copper. This suggests that the metal ions are preferably bound to the cell wall and to RPS functional groups rather than to the sheath. Therefore, the increased copper binding efficiency observed with the sheathless mutant can be attributed to the release of a polysaccharide containing larger amounts and/or more accessible functional groups (e.g., carboxyl and amide groups).


Author(s):  
Межлум Левонович Ерицян ◽  
Армен Мамиконович Арустамян ◽  
Валентина Межлумовна Мависакалян

Исследована реология водных растворов полиакриловой кислоты, полиакриламида, поливинилового спирта, сополимера акриловой кислоты с акриламидом, a также смесeй водных растворов этих полимеров. В результате образования ассоциатов между функциональными группами уаказанных полимеров значительно повышается относительная вязкость их водных растворов. Установлено, что при температуре 95C в водных растворах полиакриламида и сополимера акриловой кислоты с акриламидом происходит интенсивное выделение аммиака с одновременным образованием полимера пространственной структуры. The rheology of aqueous solutions of polyacrylic acid, polyacrylamide, polyvinyl alcohol, copolymer of acrylic acid with acrylamide, as well as mixtures of aqueous solutions of these polymers was investigated. As a result of the formation of associates between the functional groups of the polymers indicated, the relative viscosity of their aqueous solutions significantly increases. It was established that at a temperature of 95°C in aqueous solutions of polyacrylamide and a copolymer of acrylic acid and acrylamide, there is an intense release of ammonia with simultaneous formation of a polymer of spatial structure.


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