Biodegradation of Tributyl Phosphate by Naturally Occurring Microbial Isolates and Coupling to the Removal of Uranium from Aqueous Solution

1996 ◽  
Vol 30 (7) ◽  
pp. 2371-2375 ◽  
Author(s):  
Russell A. P. Thomas ◽  
L. E. Macaskie
Keyword(s):  
Aqueous Solution ◽  
Tributyl Phosphate ◽  
Naturally Occurring ◽  
Microbial Isolates

scholarly journals The biodegradation of tributyl phosphate by naturally occurring microbial isolates

2006 ◽  
Vol 155 (2) ◽  
pp. 155-159 ◽  
Author(s):  
Russell A.P. Thomas ◽  
Andy P. Morby ◽  
Lynne E. Macaskie
Keyword(s):  
Tributyl Phosphate ◽  
Naturally Occurring ◽  
Microbial Isolates

Fluorescence of the Complexes of 2-Methylnaphthoate and 2-Hydroxypropyl-α-, -β-, and -γ-Cyclodextrins in Aqueous Solution

2002 ◽  
Vol 56 (12) ◽  
pp. 1579-1587 ◽  
Author(s):  
Antonio Di Marino ◽  
Franscisco Mendicuti
Keyword(s):  
Aqueous Solution ◽  
Fluorescence Anisotropy ◽  
Intensity Ratio ◽  
Driving Forces ◽  
Emission Spectra ◽  
Formation Constants ◽  
Dielectric Constants ◽  
Additional Information ◽  
Fluorescence Techniques ◽  
Naturally Occurring

Fluorescence techniques were employed to study the inclusion complexes of 2-methylnaphthoate (MN) with 2-hydroxypropyl-α-cyclodextrin (αHPCD), 2-hydroxypropyl-β-cyclodextrin (βHPCD), and 2-hydroxypropyl-γ-cyclodextrin (γHPCD). Emission spectra of MN show two vibronic bands whose intensity ratio R is very sensitive to the polarity of the medium. The stoichiometry and formation constants of these complexes were investigated by obtaining R as a function of the cyclodextrin (CD) concentration. Results showed identical stoichiometry (1/1) for the three MN/αHPCD, MN/β-HPCD, and MN/γHPCD complexes. Formation constants at 25 °C were 780 ± 15, 2700 ± 130, and 165 ± 10 M−1, respectively. ΔH0 and ΔS0 were obtained from linear van't Hoff plots. Results reveal that the complexation of MN with αHPCD is enthalpy driven. With βHPCD, both the entropy and enthalpy terms favor the process, whereas the formation of the complex with γHPCD is entropically governed. The extrapolation of R at infinite CD concentration allows us to estimate the effective dielectric constants of the inner CD cavities, which are around 50, but which differ from their counterparts, the naturally occurring α-, β-, and γ-CDs. Fluorescence anisotropy, quencher lifetimes, and average lifetimes can also give additional information about the structure and driving forces accompanying the formation of such complexes.

scholarly journals Stabilisation of Natural Colourants and Lignocellulosic Textiles

2021 ◽  
Author(s):  
◽  
Ying Tang
Keyword(s):  
Reactive Oxygen Species ◽  
Aqueous Solution ◽  
Textile Fibre ◽  
Oxygen Species ◽  
Blue Fluorescence ◽  
Esi Ms ◽  
Naturally Occurring ◽  
Antifungal Effects ◽  
Fluorescent Whitening Agents ◽  
Cyclobutane Ring

<p>The lignocellulosic fibres extracted from the leaves of New Zealand flax, Phormium tenax, have been used as the principal textile fibre by Maori since pre- European times. Variations of antifungal activity were observed in Phormium fibres of different cultivars. The most resistant cultivars of P. tenax in an aqueous antifungal assay also possessed the greatest variety of naturally-occurring 7-hydroxycoumarins as identified by mass spectroscopy, ESI-MS. In addition to antifungal effects, coumarins function as fluorescent whitening agents in Phormium fibres and play a role in the fibre’s photodegradation. Ultraviolet irradiation (350 – 400 nm) of the fibre resulted in a substantial loss of the blue fluorescence originating from a number of 7-hydroxycoumarins present, together with the formation of new fluorophores absorbing and emitting at longer wavelengths, which contribute to the photoyellowing of the fibre. The photolysis of two standard 7-hydroxycoumarins in aqueous solution was examined and two primary photoproducts were elucidated by ESI-MS: a photodimer containing a linking cyclobutane ring and a monomeric photooxidation product. The formation of at least some of the photoproducts is associated with the coumarin-sensitised generation of reactive oxygen species, hydrogen peroxide and superoxide. The fluorescence properties and photodegradation of Chinese handmade papers were also investigated. Papers manufactured by traditional methods were found to be more photostable than that produced from chemically-facilitated techniques.</p>

Removal of Phenol from an Aqueous Solution Using Hydrogel Incorporated with Extractant Tributyl Phosphate

2004 ◽  
Vol 37 (10) ◽  
pp. 1279-1283 ◽  
Author(s):  
Keiji Igarashi ◽  
Yutaka Yamada ◽  
Ken-ichi Kurumada
Keyword(s):  
Aqueous Solution ◽  
Tributyl Phosphate

STUDIES ON THE URANIUM EXTRACTION EQUILIBRIA, PHOTOLYTIC, AND HYDROLYTIC REACTIONS IN SYSTEMS CONTAINING TRI-n-BUTOXYETHYL PHOSPHATE

1964 ◽  
Vol 42 (4) ◽  
pp. 878-884 ◽  
Author(s):  
M. Halpern ◽  
T. Kim ◽  
A. S. Kertes ◽  
N. C. Li
Keyword(s):  
Aqueous Solution ◽  
Hydrochloric Acid ◽  
Organic Phase ◽  
Acid Content ◽  
Tributyl Phosphate ◽  
Extraction Behavior ◽  
Initial Aqueous Solution ◽  
Hydrolysis Of ◽  
Ethereal Oxygen ◽  
Extraction Equilibria

The extraction equilibria in the system aqueous hydrochloric acid – uranyl chloride –undiluted tri-n-butoxyethyl phosphate, TBEP, were examined as a function of increasing uranyl concentration (0.44 to 4.41 M) in the initial aqueous solution, the acid content of the initial aqueous solution being kept constant at 6.76 M. The extraction behavior of TBEP is found to be different from that of tributyl phosphate. Evidence has been presented to show that the three ethereal oxygen atoms in the TBEP molecule are, under high organic phase loading conditions, available for participation in complexation. The hydrochloric acid promoted hydrolysis of TBEP and the instability toward light of the TBEP layer containing hydrochloric acid and uranium were also examined.

scholarly journals KOEFISIEN PERPINDAHAN MASSA VOLUMETRIS KESELURUHAN PADA EKSTRAKSI Cu DARI LARUTAN CuSO4.5H2O DENGAN TRIRUTYL PHOSPHATE-KEROSIN DALAM DOUBLE-STAGE MIXER-SETTLER

2018 ◽  
Vol 7 (1) ◽  
pp. 731
Author(s):  
Panut Mulyono
Keyword(s):  
Aqueous Solution ◽  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Tributyl Phosphate ◽  
Continuous Phase ◽  
Hole Diameter ◽  
Extraction Column ◽  
Dispersed Phase ◽  
Dilute Aqueous Solution

Copper has been extracted by trtbuthyl phosphate-kerosene from a dilute aqueous solution with a double- stage mixer-settler extraction column. The extraction column used in this experiment was made of glass. The mixer diameter was equal to the diameter of settler was 13 cm. Both the mixer and settler heights were 8 cm. Drop coalescer was mounted in the middle of mixer and settler separator. The diameter of drop coalescer was 6 cm with the thickness of 1 cm. The hole diameter of drop coalescer was 1 mm The stirrer used in this experiment was cross flat blade with the diameter and width of the impeller was 6 cm and 8 mm, respectively. The overall volumetric coefficient of mass transfer (Kca) increased by increasing the flowrate of the continuous phase (Lc) at the constants stirring speed (N) and flowrate of the dispersed phase (Ld). The increase of Lc from 4.1634 cm3/second to 17.9436 cm3/second increased the Kca value from 6.6387x10-5/second to 23.1561x10-5/second or 248.8% The value of Kca was also increase by increasing N at the constant values of Lc and Ld Thie increase of N from 3.3333 rps to 8.3333 rps increased the Kca value from 6.0288x10-5/second to 6.6387x10-5/second or 10.1%.Keywords: Mass Transfer Coefficient, Extraction, Copper, Double-Stage Mixer-SettlerAbstrak Penelitian ini mempelajari perpindahan massa antar fasa pada ekstraksi Cu dart larutan CuSO4.5H2O dengan menggunakan pelarut tributyl phosphate dalam kerosin yang dilakukan dalam kolom ekstraksi double-stage mixer-settler yang dtsusun vertikal. Kolom ekstraksi mixer-settler dibuat darti gelas dengan diameter mixer sama dengan diameter sealer, yaitu 13 cm. Tinggi mixer juga sama dengan tinggt settler, yaitu 8 cm. Diameter drop coalescer 8 cm, tebal 1 cm, dan diameter lubangnya 1 mm. Pengaduk yang digunakan berbentuk flat blade dengan diameter 6 cm dan lebar blade 8 mm. Koeftsien perpindahan massa volumetris keseluruhan (Kca) naik dengan naiknya kecepatan alir fasa kontinyu (Lc) pada kecepatan putaran pengaduk (N) dan kecepatan alir fasa dispersi (Ld) tetap. Kenatkan nilai Lc dart 4,1634 cm3/detik menjadi 17,9436 cm3/detik meningkatkan nilai Kca dart 6,6387x10-5/detik menjadi 23,1561x10-5/detik atau 248,8% Kca juga naik dengan naiknya N pada Lc dan Ld yang tetap. Kenaikan nilai N dart 3,3333 rps menjadi 8,3333 rps meningkatkan nilai Kca dart 6,0288x10-5/detik menjadt 6,6387x10-5/detik atau 10,1%.Kata Kunci : Koefesien Perpindahan Massa, Ekstraksi, Tembaga, Double-Stage Mixer-Settler

The chemical stability of mimetite and distribution coefficients for pyromorphite–mimetite solid-solutions

1989 ◽  
Vol 53 (371) ◽  
pp. 363-371 ◽  
Author(s):  
Adedayo I. Inegbenebor ◽  
John H. Thomas ◽  
Peter A. Williams
Keyword(s):  
Solid Solution ◽  
Aqueous Solution ◽  
Solid Phase ◽  
Distribution Coefficients ◽  
Solid Solution Series ◽  
Solution Series ◽  
Ph Values ◽  
Naturally Occurring ◽  
Phosphate Species ◽  
End Members

AbstractThe equilibrium solubility of mimetite has been determined in aqueous solution at 298.2K. For the reaction Pb5(ASO4)3Cl(s,mimetite)+6H+(aq)⇌5Pb2+(aq)+3H2AsO4−(aq)+Cl−(aq) at this temperature log KH+, extrapolated to zero ionic strength, is equal to −27.9(4). This value is equal, within experimental error, to that corresponding to pyromorphite, Pb5(PO4)3Cl, derived from the literature, and redetermined here under analogous conditions. Distribution coefficients in terms of both HXO42− and H2XO4−(aq) ions (X = P,As) have also been determined for solid phases of the pyromorphite-mimetite solid solution series containing from 5 to 95 mol. % mimetite. Although the two end-members are isostructural without being strictly isomorphous, the solid solution series behaves ideally over the whole compositional range; that is, the composition of the solid phase reflects the ratio of arsenate to phosphate species in aqueous solution at pH values corresponding to naturally-occurring aqueous solutions generally associated with the oxidized zones of base metal orebodies. Some relationships between mimetite and other secondary lead(II) and copper(II) arsenate minerals have been explored.

scholarly journals The Removal Performance and Mechanisms of Tetracycline Over Mn-rich Limonite

2021 ◽  
Author(s):  
Luyao Wang ◽  
Hanlin Wang ◽  
Haibo Liu ◽  
Xuehua Zou ◽  
Dong Chen ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Physicochemical Properties ◽  
Active Sites ◽  
Manganese Oxides ◽  
Mesoporous Structure ◽  
High Specific Surface Area ◽  
Solution Ph ◽  
Natural Mineral ◽  
Naturally Occurring ◽  
Ft Ir

Abstract Naturally occurring Mn-rich limonite mainly composed of goethite and manganese oxides was used to remove tetracycline (TC) from the aqueous solution. The physicochemical properties of limonite were illustrated by various characterization techniques such as XRD, FE-TEM, XPS and FT-IR. The effects of dosage, initial solution pH, temperature and coexisting anions on TC removal were investigated. The results showed that TC could be efficiently adsorbed by limonite with high specific surface area and mesoporous structure through electrostatic interaction and complexation. The co-existence of PO43- inhibited the adsorption of TC by limonite due to the competition with TC for active sites. In addition, manganese oxides exhibited oxidative properties to TC, and the singlet oxygen (1O2) generated during the redox reaction was responsible for TC degradation. Furthermore, the regenerated limonite displayed an efficient recycling performance after four cycles. This study revealed that the Mn-rich limonite was a promising adsorbent for TC removal from aqueous solutions and promoted the application of natural mineral material in the environmental field.

Growth of naturally occurring microbial isolates in metal-citrate medium and bioremediation of metal-citrate wastes

2000 ◽  
Vol 75 (3) ◽  
pp. 187-195 ◽  
Author(s):  
Russell AP Thomas ◽  
Alan J Beswick ◽  
Gabriela Basnakova ◽  
Rachel Moller ◽  
Lynne E Macaskie
Keyword(s):  
Naturally Occurring ◽  
Microbial Isolates
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