scholarly journals Galvanic Wastewater Treatment by Means of Anionic Polymer Enhanced Ultrafiltration

2012 ◽  
Vol 19 (1) ◽  
pp. 19-27 ◽  
Author(s):  
Irena Korus
Keyword(s):  
Wastewater Treatment ◽  
Metal Binding ◽  
Metal Ion ◽  
Water Soluble ◽  
Partial Recovery ◽  
Solution Ph ◽  
Anionic Polymer ◽  
Metal Retention ◽  
Metal Separation ◽  
Polymer Metal

Galvanic Wastewater Treatment by Means of Anionic Polymer Enhanced Ultrafiltration This work is focused on polyelectrolyte enhanced ultrafiltration as an effective heavy metal separation technique. Three types of effluents, containing Zn(II), Cu(II) and Ni(II) ions, were subjected to the separation process. Poly(sodium 4-styrenesulfonate) - PSSS, a water soluble anionic polyelectrolyte was used as a metal binding agent. Two Sepa® CF (Osmonics) membranes: EW, made of polysulfone and a modified polyacrylonitrile membrane MW, were used in the ultrafiltration process. The preliminary UF tests were carried out on model solutions with target metal ion concentrations of 10, 100 and 250 mg dm-3. The main parameters affecting the metal retention (the polyelectrolyte quantity and solution pH) were examined. The values of pH 6 and polymer : metal concentration ratio CPSSS : CM = 7.5 : 1 (mol of mer unit per mol of metal) were selected to perform the galvanic wastewater ultrafiltration-concentration tests. Three types of wastewater containing Zn(II), Ni(II) and Cu(II) ions within the concentration range of 30÷70 mg dm-3 were used in the investigations. Very high metal retention coefficients, up to > 99%, were achieved. The retentates obtained were subjected to the decomplexation-ultrafiltration (pH = 1) and subsequent diafiltration step, which enabled partial recovery of concentrated metal ions and the polyelectrolyte. The recovered polyelectrolyte was reused toward Ni(II) ions and the high effectiveness of metal separation has been achieved.

Metal Binding by Water-Soluble Polychelates and Implications for Agriculture

2011 ◽  
Vol 64 (12) ◽  
pp. 1593 ◽  
Author(s):  
Garry W. Warrender ◽  
Robert G. Gilbert
Keyword(s):  
Metal Ions ◽  
Atomic Absorption ◽  
Emulsion Polymerization ◽  
Atomic Absorption Spectroscopy ◽  
Metal Binding ◽  
Metal Ion ◽  
Agricultural Soils ◽  
Water Soluble ◽  
Aminosalicylic Acid ◽  
Chemical Binding

Means are developed to improve the metal ion delivery/remediation potential of polyacrylamides (PAMs), by incorporation of the co-monomer N-acryloyl-4-aminosalicylic acid. The polymers were synthesized by solution and inverse emulsion polymerization. The chemical binding of two soil micronutrients, Cu2+ and Fe3+, were investigated using atomic absorption spectroscopy. The modified PAM had an enhanced affinity for metal ions compared with conventional PAMs. This modified PAM has the potential as a delivery tool of plant micronutrients and stabilizers for agricultural soils undergoing intense irrigation. The same polymers may also provide a detoxifying effect in these applications where some micronutrient sources may be in excess and detrimental to productive agriculture.

Optically active J-aggregate formed from water-soluble porphyrin with phenylalanine

2012 ◽  
Vol 16 (12) ◽  
pp. 1285-1292 ◽  
Author(s):  
Yoshio Uemori ◽  
Hiroki Munakata ◽  
Sakiko Kitazawa ◽  
Astuko Osada ◽  
Hiroyasu Imai
Keyword(s):  
Aqueous Solution ◽  
Metal Ion ◽  
Cd Spectroscopy ◽  
Optically Active ◽  
Water Soluble ◽  
Cd Spectra ◽  
Solution Ph ◽  
Chiral Compound ◽  
Water Soluble Porphyrin ◽  
Soret Region

A water-soluble porphyrin bearing multi-dentate ligands was prepared, and its aggregation behavior in solution under various conditions (temperature, pH, metal ion, chiral compound) was investigated using UV-vis absorption spectroscopy, fluorescence spectroscopy, circular dichroism (CD) spectroscopy. Upon the addition of Ca2+, Ba2+ , or Sr2+ to a solution of porphyrin, the porphyrin first forms an H-aggregate and is then transformed to a J-aggregate at 25 °C in buffered aqueous solution (pH 7.4). On the other hand, the porphyrin forms a self-aggregate (H-aggregate) at 25 °C in buffered aqueous solution (pH 6.0), and the H-aggregate does not form the J-aggregate upon the addition of the group II metal ions. The measurement of CD spectra revealed that the H-aggregate that forms right after the addition of Ba2+ to the porphyrin solution in the presence of D- or L-phenylalanine does not show an induced CD signal, while the J-aggregate formed from the H-aggregate shows induced CD signals in the Soret region.

Aminodiacetic water-soluble polymer–metal ion interactions

2008 ◽  
Vol 44 (7) ◽  
pp. 2330-2338 ◽  
Author(s):  
Bernabé L. Rivas ◽  
Antonio E. Maureira ◽  
María A. Mondaca
Keyword(s):  
Metal Ion ◽  
Water Soluble ◽  
Soluble Polymer ◽  
Water Soluble Polymer ◽  
Ion Interactions ◽  
Polymer Metal ◽  
Metal Ion Interactions

Functional water-soluble polymers: polymer-metal ion removal and biocide properties

2009 ◽  
Vol 58 (10) ◽  
pp. 1093-1114 ◽  
Author(s):  
Bernabé L Rivas ◽  
Eduardo Pereira ◽  
Antonio Maureira
Keyword(s):  
Metal Ion ◽  
Water Soluble ◽  
Water Soluble Polymers ◽  
Metal Ion Removal ◽  
Soluble Polymers ◽  
Ion Removal ◽  
Polymer Metal

scholarly journals Optimization of Ni(II), Pb(II), and Zn(II) Ion Adsorption Conditions on Pliocene Clays from Post-Mining Waste

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 568
Author(s):  
Beata Jabłońska
Keyword(s):  
Wastewater Treatment ◽  
Metal Ion ◽  
Groundwater Remediation ◽  
Mineralogical Composition ◽  
Ion Concentration ◽  
Point Of Zero Charge ◽  
Effect Of Temperature ◽  
Solution Ph ◽  
Water And Wastewater Treatment ◽  
Water And Wastewater

Lignite mining results in a significant amount of waste clayey materials—the so-called Pliocene clays, which are often considered useless mineral waste. One method of management is to use them as inexpensive adsorbents in water and wastewater treatment, or as permeable barriers in groundwater remediation. The study is an attempt to use the raw Pliocene clays to remove Pb(II), Ni(II), and Zn(II) ions from wastewaters. The mineralogical composition, physicochemical, granulometric, structural, and surface properties were examined. The value of the point of zero charge pH of the adsorbent was found to be 7.1. To determine the optimal adsorption conditions, the central composite design (CCD) method was used with the pH of the solution, metal ion concentration, and the adsorbent mass as independent variables, and the percentage removal as the response variable. The determined optimal values of the adsorbent mass and the solution pH turned out to be similar for all three metals, with a pH of 6–7 and an adsorbent dose of 18–24 g/dm3. In further tests, the pH was established slightly lower than it would appear from the CCD method in order to avoid the possible precipitation of metals in the form of hydroxides. The kinetics of sorption were investigated and it was found that the sorption process ran for several minutes. The effect of temperature showed that the adsorption was spontaneous and thermodynamically favored. The leachability of the metals indicated that Pb(II) and Zn(II) were strongly bound in the adsorbent, whereas Ni(II) manifested a larger mobility. It was found that the tested clays had quite good sorption properties in relation to the tested metal ions and could be used for water and wastewater treatment.

Water-Soluble Polymers and Their Polymer-Metal Ion-Complexes as Antibacterial Agents

2010 ◽  
Vol 287 (1) ◽  
pp. 69-79 ◽  
Author(s):  
Bernabé L. Rivas ◽  
Antonio Maureira N. ◽  
Catherine Guzmán S.
Keyword(s):  
Metal Ion ◽  
Antibacterial Agents ◽  
Water Soluble ◽  
Metal Ion Complexes ◽  
Water Soluble Polymers ◽  
Soluble Polymers ◽  
Polymer Metal

Structures of c-di-GMP/cGAMP degrading phosphodiesterase VcEAL: identification of a novel conformational switch and its implication

2019 ◽  
Vol 476 (21) ◽  
pp. 3333-3353 ◽  
Author(s):  
Malti Yadav ◽  
Kamalendu Pal ◽  
Udayaditya Sen
Keyword(s):  
Active Site ◽  
Metal Binding ◽  
Metal Ion ◽  
Triosephosphate Isomerase ◽  
Catalytic Mechanism ◽  
Degradation Mechanism ◽  
Structural Basis ◽  
Conserved Residues ◽  
Phosphodiester Bond ◽  
Cyclic Dinucleotides

Cyclic dinucleotides (CDNs) have emerged as the central molecules that aid bacteria to adapt and thrive in changing environmental conditions. Therefore, tight regulation of intracellular CDN concentration by counteracting the action of dinucleotide cyclases and phosphodiesterases (PDEs) is critical. Here, we demonstrate that a putative stand-alone EAL domain PDE from Vibrio cholerae (VcEAL) is capable to degrade both the second messenger c-di-GMP and hybrid 3′3′-cyclic GMP–AMP (cGAMP). To unveil their degradation mechanism, we have determined high-resolution crystal structures of VcEAL with Ca2+, c-di-GMP-Ca2+, 5′-pGpG-Ca2+ and cGAMP-Ca2+, the latter provides the first structural basis of cGAMP hydrolysis. Structural studies reveal a typical triosephosphate isomerase barrel-fold with substrate c-di-GMP/cGAMP bound in an extended conformation. Highly conserved residues specifically bind the guanine base of c-di-GMP/cGAMP in the G2 site while the semi-conserved nature of residues at the G1 site could act as a specificity determinant. Two metal ions, co-ordinated with six stubbornly conserved residues and two non-bridging scissile phosphate oxygens of c-di-GMP/cGAMP, activate a water molecule for an in-line attack on the phosphodiester bond, supporting two-metal ion-based catalytic mechanism. PDE activity and biofilm assays of several prudently designed mutants collectively demonstrate that VcEAL active site is charge and size optimized. Intriguingly, in VcEAL-5′-pGpG-Ca2+ structure, β5–α5 loop adopts a novel conformation that along with conserved E131 creates a new metal-binding site. This novel conformation along with several subtle changes in the active site designate VcEAL-5′-pGpG-Ca2+ structure quite different from other 5′-pGpG bound structures reported earlier.

scholarly journals Identification and functional analysis of cadmium-binding protein in the visceral mass of Crassostrea gigas

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zehua Zheng ◽  
Kazuhiro Kawakami ◽  
Dingkun Zhang ◽  
Lumi Negishi ◽  
Mohamed Abomosallam ◽  
...  
Keyword(s):  
Crassostrea Gigas ◽  
Metal Ion ◽  
Defense Mechanisms ◽  
Three Dimensional ◽  
Tryptophan Fluorescence ◽  
Water Soluble ◽  
Titration Calorimetry ◽  
Visceral Mass ◽  
The Pacific ◽  
Liquid Chromatography Tandem Mass

AbstractThe Pacific oyster, Crassostrea gigas, is a traditional food worldwide. The soft body of the oyster can easily accumulate heavy metals such as cadmium (Cd). To clarify the molecular mechanism of Cd accumulation in the viscera of C. gigas, we identified Cd-binding proteins. 5,10,15,20-Tetraphenyl-21H,23H-porphinetetrasulfonic acid, disulfuric acid, tetrahydrate, and Cd-binding competition experiments using immobilized metal ion affinity chromatography revealed the binding of water-soluble high molecular weight proteins to Cd, including C. gigas protein disulfide isomerase (cgPDI). Liquid chromatography–tandem mass spectrometry (LC–MS/MS) analyses revealed two CGHC motifs in cgPDI. The binding between Cd and rcgPDI was confirmed through a Cd-binding experiment using the TPPS method. Isothermal titration calorimetry (ITC) revealed the binding of two Cd ions to one molecule of rcgPDI. Circular dichroism (CD) spectrum and tryptophan fluorescence analyses demonstrated that the rcgPDI bound to Cd. The binding markedly changed the two-dimensional or three-dimensional structures. The activity of rcgPDI measured by a PDI Activity Assay Kit was more affected by the addition of Cd than by human PDI. Immunological analyses indicated that C. gigas contained cgPDI at a concentration of 1.0 nmol/g (viscera wet weight). The combination of ITC and quantification results revealed that Cd-binding to cgPDI accounted for 20% of the total bound Cd in the visceral mass. The findings provide new insights into the defense mechanisms of invertebrates against Cd.

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