scholarly journals Thermodynamics Analysis and Removal of P in a P-(M)-H2O System

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3342
Author(s):  
Hao Peng ◽  
Jing Guo ◽  
Hongzhi Qiu ◽  
Caiqiong Wang ◽  
Chenyu Zhang ◽  
...  

In order to efficiently remove phosphorus, thermodynamic equilibrium diagrams of the P-H2O system and P-M-H2O system (M stands for Fe, Al, Ca, Mg) were analyzed by software from Visual MINTEQ to identify the existence of phosphorus ions and metal ions as pH ranged from 1 to 14. The results showed that the phosphorus ions existed in the form of H3PO4, H2PO4−, HPO42−, and PO43−. Among them, H2PO4− and HPO42− were the main species in the acidic medium (99% at pH = 5) and alkaline medium (97.9% at pH = 10). In the P-Fe-H2O system ((P) = 0.01 mol/L, (Fe3+) = 0.01 mol/L), H2PO4− was transformed to FeHPO4+ at pH = 0–7 due to the existence of Fe3+ and then transformed to HPO42− at pH > 6 as the Fe3+ was mostly precipitated. In the P-Ca-H2O system ((P) = 0.01 mol/L, (Ca2+) = 0.015 mol/L), the main species in the acidic medium was CaH2PO4+ and HPO42−, and then transformed to CaPO4− at pH > 7. In the P-Mg-H2O system ((P) = 0.01 mol/L, (Mg2+) = 0.015 mol/L), the main species in the acidic medium was H2PO4− and then transformed to MgHPO4 at pH = 5–10, and finally transformed to MgPO4− as pH increased. The verification experiments (precipitation experiments) with single metal ions confirmed that the theoretical analysis could be used to guide the actual experiments.

RSC Advances ◽  
2016 ◽  
Vol 6 (78) ◽  
pp. 74886-74894 ◽  
Author(s):  
Lili Cui ◽  
Mei Wu ◽  
Jinbao Xiang

Fe/N-GAs exhibit comparable electrocatalytic activity to commercial Pt/C in alkaline medium together with enhanced activity compared to N-GAs in acidic medium.


2019 ◽  
Vol 7 (45) ◽  
pp. 25865-25877 ◽  
Author(s):  
Aliki Moysiadou ◽  
Xile Hu

Metal oxides undergo compositional changes due to a dynamic exchange of metal ions with the electrolyte solutions during the oxygen evolution reaction.


1997 ◽  
Vol 80 (2) ◽  
pp. 388-391 ◽  
Author(s):  
Ritu Kesari ◽  
Manish Rai ◽  
Vinay Kumar Gupta

Abstract A sensitive spectrophotometric method was developed for determination of paraquat, a widely used herbicide. Paraquat was reduced with glucose in an alkaline medium, and the blue radical ion obtained was measured at 600 nm. Beer’s law was obeyed at 0.1–1.2 ppm paraquat. The molar absorptivity was 1.26 × 105 L mol-1 cm-1. The standard deviation and relative standard deviation were ± 0.007 and 2.0%, respectively, for 5 μg paraquat/10 mL analyzed over 7 days. The method was free from interference by other commonly used pesticides and metal ions. The method may be used to the determine paraquat in plants, fruits, grains, water, blood, and urine.


Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4681
Author(s):  
Nikolay I. Gorshkov ◽  
Andrey Yu. Murko ◽  
Irina I. Gavrilova ◽  
Marina A. Bezrukova ◽  
Albert I. Kipper ◽  
...  

Dithiocarbamate (DTC) derivatives of N-vinylpyrrolidone-N-vinylamine (VP–VA) copolymers were synthesized via reaction between the copolymers and carbon disulfide in alkaline medium; molecular masses of the products were 12 and 29 kDa; the VP:VDTC ratios were 94:6 and 83:17 mol.%. Complexation between the obtained DTC derivatives and metal ions (indium and gallium) was investigated. It was demonstrated that metal–DTC ligand complexes with 1:3 ratio between components were formed. Gallium metal–polymer complexes (MPC) were unstable in solution. Individual indium MPC were isolated and characterized by spectral and chromatographic methods. Unlike similar gallium MPC, they appeared to be stable in histidine challenge reaction.


Author(s):  
Harichandra A Parbat ◽  
D V Prabhu ◽  
Anna Pratima Nikalje

Oxidation of alcohols has industrial importance as it yields several useful products.Toxic and costly metal ions like Os(VIII), Cr(VI), and Ru in different oxidation states are widely used for the oxidation of a variety of organic compounds. We are reporting herein the oxidation of the industrially useful primary alcohols, 2-Chloroethanol, 2-Butoxyethanol and 2-Phenoxyethanol using Ammonium metavanadate in acidic medium. Relatively less toxic and cheaper transition metal ions of the first series are effectively used as homogeneous catalysts for the oxidation of the alcohols to the corresponding aldehydes. 2- Chloroethanol is used as a precursor for ethylene oxide and is useful in the manufacture of crop protection chemicals, and pharmaceuticals.2-Butoxyethanol finds use in the making of paints, varnishes and industrial and household cleaners.


Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1568
Author(s):  
Sveta Zhiraslanovna Ozkan ◽  
Aleksandr Ivanovich Kostev ◽  
Galina Petrovna Karpacheva ◽  
Petr Aleksandrovich Chernavskii ◽  
Andrey Aleksandrovich Vasilev ◽  
...  

Hybrid ternary nanomaterials based on conjugated polymer polydiphenylamine-2-carboxylic acid (PDPAC) (poly-N-phenylanthranilic acid), Fe3O4 nanoparticles and single-walled carbon nanotubes (SWCNT) were prepared for the first time. Polymer–metal–carbon Fe3O4/SWCNT/PDPAC nanocomposites were synthesized via in situ oxidative polymerization of diphenylamine-2-carboxylic acid (DPAC) by two different ways: in an acidic medium and in the interfacial process in an alkaline medium. In an alkaline medium (pH 11.4), the entire process of Fe3O4/SWCNT/PDPAC-1 synthesis was carried out in one reaction vessel without intermediate stages of product extraction and purification. In an acidic medium (pH 0.3), to prepare the Fe3O4/SWCNT/PDPAC-2 nanocomposites, prefabricated magnetite nanoparticles were deposited on the surface of obtained SWCNT/PDPAC-2. The phase composition of the nanocomposites does not depend on the synthesis reaction medium pH. The influence of the reaction medium pH on the structure, morphology, thermal, magnetic, and electrical properties of the obtained ternary nanocomposites was studied.


2019 ◽  
Vol 21 (11) ◽  
pp. 6059-6070
Author(s):  
Dominik Sidler ◽  
Sereina Riniker

An extension of the Nosé–Hoover thermostat equation for molecular dynamics (MD) simulation is introduced, which perturbs fast degrees of freedom out of canonical equilibrium, while preserving the average temperature of the system.


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