1327-52-2Relevant articles and documents
Rapid catalytic oxidation of As(iii) to As(v) using a: Bacillus spore-2,2,6,6-tetramethylpiperidine-1-oxyl system
Qin, Yuqing,Peng, Fei,Hu, Yonggang
, p. 2286 - 2294 (2019/05/21)
The oxidation of As(iii) to As(v) is a critical process in the treatment of contaminated water. We found that 95% As(iii) (10 mg L-1) could be rapidly oxidized to As(v) by a laccase-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) system in 1 h. Based on this finding, we used Bacillus subtilis spores instead of laccase for As(iii) oxidation with the same effect because the former had plenty of CotA-laccase on their surface. The catalytic ability of CotA protein and spores was confirmed by expressing the CotA protein and knocking out the cotA gene from wild-type spores. Both laccase- and spore-TEMPO systems displayed similar oxidation rate constants, Michaelis-Menten constants, and maximal velocities owing to the formation of the oxoammonium cation of TEMPO in the presence of dissolved oxygen. Several other laccase mediators such as 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic-acid) (ABTS), acetosyringone (AS), 1-hydroxybenzotriazole (HBT), 2-hydroxybutyl acrylate (HBA), violuric acid (VLA), 4-oxo-TEMPO, 4-amino-TEMPO, 4-methoxy-TEMPO, 4-hydroxy-TEMPO benzoate, and 4-hydroxy-TEMPO coupled with spores for As(iii) oxidation were also investigated in detail. The spore-TEMPO system exhibited the highest oxidation efficiency and tolerated the addition of 10 mg L-1 Al3+, Ti4+, Cu2+, K+, Fe3+, Zn2+, Ni2+, Mg2+, Co2+, and Mn2+. Both laccase and spores recovered via ultrafiltration and centrifugation, respectively, could be reused for at least five cycles. The developed spore-based system has several advantages including eco-friendliness, ease of operation and storage, low cost, recyclability, sustainability, and without the need for enzyme purification. These findings may have promising implications for developing a new eco-friendly and cost-effective technology for the treatment of arsenic-containing water.
Synthesis, structure, and thermal expansion of sodium zirconium arsenate phosphates
Sukhanov,Pet'Kov,Firsov,Kurazhkovskaya,Borovikova
, p. 1351 - 1357 (2011/12/14)
Sodium zirconium arsenate phosphates NaZr2(AsO4) x (PO4)3-x were synthesized by precipitation technique and studied by X-ray diffraction and IR spectroscopy. In the series of NaZr2(AsO4) x (PO4)3-x, continuous substitution solid solutions are formed (0 ≤ x ≤ 3) with the mineral kosnarite structure. The crystal structure of NaZr2(AsO 4)1.5(PO4)1.5 was refined by full-profile analysis: space group R c, a = 8.9600(4)?, c = 22.9770(9) ?, V = 1597.5(1) ?3, R wp = 4.55. The thermal expansion of the arsenate-phosphate NaZr2(AsO4) 1.5(PO4)1.5 and the arsenate NaZr 2(AsO4)3 was studied by thermal X-ray diffraction in the temperature range of 20-800°C. The average linear thermal expansion coefficients (αav = 2.45 × 10-6 and 3.91 × 10-6 K-1, respectively) indicate that these salts are medium expansion compounds.
Synthesis and TG/DTA study on two new metallo(VI)-arsenato(V) heteropolyacids containing vanadium(V)
Fodor,Ghizdavu,?uteu,Caraban
, p. 153 - 158 (2008/10/09)
An improved method for the synthesis of two heteropolyacids of the same type: H5[AsMo10V2O40]· 13H2O and H5[AsW10V2O40] ·16H2O was elaborated. Th
