scholarly journals Degradation of Reactive Blue 19 (RB19) by a Green Process Based on Peroxymonocarbonate Oxidation System

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Thi Bich Viet Nguyen ◽  
Ngan Nguyen-Bich ◽  
Ngoc Duy Vu ◽  
Hien Ho Phuong ◽  
Hanh Nguyen Thi

The effectiveness of peroxymonocarbonate ( HCO 4 − ) on the degradation of Reactive Blue 19 (RB19) textile dye was investigated in this study. The formation kinetics of HCO 4 − produced in situ in a H 2 O 2 − HCO 3 − system was studied to control the experimental conditions for the investigation of RB19 degradation at mild conditions. The effects of metallic ion catalysts, the pH, the input HCO 3 − and Co2+ concentrations, and UV irradiation were studied. The obtained result showed that Co2+ ion gave the highest efficiency on accelerating the rate of RB19 degradation by the H2O2– HCO 3 − system. In the pH range of 7–10, the higher pH values resulted in faster dye degradation. The reaction orders of the RB19 degradation with respect to Co2+ and HCO3– were determined to be 1.2 and 1.7, respectively. The UV irradiation remarkably enhanced the radical formation in the oxidation system, which led to high degradation efficiencies. The COD, TOC removal, and HPLC results clearly revealed complete mineralization of RB19 by the H 2 O 2 − HCO 3 − − Co 2 + system.

RSC Advances ◽  
2016 ◽  
Vol 6 (5) ◽  
pp. 3552-3560 ◽  
Author(s):  
Sivasankar Annamalai ◽  
Manikandan Santhanam ◽  
Subramanian Sudanthiramoorthy ◽  
Kannan Pandian ◽  
Marta Pazos

The present study focuses on the electrokinetic process for the in situ formation of electroactive species at the anode.


Environments ◽  
2019 ◽  
Vol 6 (9) ◽  
pp. 101 ◽  
Author(s):  
Pierantonio De Luca ◽  
Paola Foglia ◽  
Carlo Siciliano ◽  
Jànos B. Nagy ◽  
Anastasia Macario

This work aims to investigate possible interferences due to the presence of sodium carbonate on the photodegradation of the reactive Black 5 azoic dye, both in systems containing only titanium oxide and those containing titanium oxide and hydrogen peroxide. The role of hydrogen peroxide is explicitly treated. Sodium carbonate, in fact, is often present in the wastewater of textile industries as it is used in the fiber dyeing phases. The use of TiO2 nanoparticles is emphasized, and the possible danger is underlined. Each system was subjected to ultraviolet irradiation (UV) by varying the exposure time. After the photodegrading tests, the resulting solutions were analyzed by UV-vis spectrophotometry and High-Resolution Nuclear Magnetic Resonance to measure the residual concentrations of dye. The dye degradation curves and reaction rates for different UV exposure times were obtained and discussed as a function of the used additives. All the data are repeated three times, and they differ only by a maximum of 5%. The results indicated a reduction of about 50% of the initial concentration of Reactive Black 5 after 30 min under optimal experimental conditions. The NMR analysis indicated the formation of a series of aromatic structures that were generated by the UV-induced photochemical fragmentation of the original molecule.


2021 ◽  
Vol 23 ◽  
pp. 101030
Author(s):  
Kitirote Wantala ◽  
Totsaporn Suwannaruang ◽  
Janthip Palalerd ◽  
Prae Chirawatkul ◽  
Narong Chanlek ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jing Li ◽  
Xiaoxia Chang ◽  
Haochen Zhang ◽  
Arnav S. Malkani ◽  
Mu-jeng Cheng ◽  
...  

AbstractRigorous electrokinetic results are key to understanding the reaction mechanisms in the electrochemical CO reduction reaction (CORR), however, most reported results are compromised by the CO mass transport limitation. In this work, we determined mass transport-free CORR kinetics by employing a gas-diffusion type electrode and identified dependence of catalyst surface speciation on the electrolyte pH using in-situ surface enhanced vibrational spectroscopies. Based on the measured Tafel slopes and reaction orders, we demonstrate that the formation rates of C2+ products are most likely limited by the dimerization of CO adsorbate. CH4 production is limited by the CO hydrogenation step via a proton coupled electron transfer and a chemical hydrogenation step of CO by adsorbed hydrogen atom in weakly (7 < pH < 11) and strongly (pH > 11) alkaline electrolytes, respectively. Further, CH4 and C2+ products are likely formed on distinct types of active sites.


2013 ◽  
Vol 777 ◽  
pp. 101-105
Author(s):  
Jie Zhang ◽  
Wei Qian Pan ◽  
Tong Zheng ◽  
Peng Wang

To achieve efficient removal of phenolic pollutants in water, the catalyst of Fe (III)-Cu (II)/γ-Al2O3 was prepared. In the presence of Fe (III)-Cu (II)/γ-Al2O3, microwave-induced hydrogen peroxide (H2O2) catalytic oxidation process was conducted for the treatment of synthetic wastewater containing PNP, a representative of phenolic pollutants. Effectiveness of the process and factors influencing PNP removal were investigated and results showed microwave-induced H2O2-Fe (III)-Cu (II)/γ-Al2O3 process could achieve 99.41% PNP removal percentage, corresponding to 77.9% TOC removal in a given condition. The process remained effective in the 2-8 pH range with high reusability of Fe (III)-Cu (II)/γ-Al2O3 catalyst. The kinetics study showed microwave-induced H2O2-Fe (III)-Cu (II)/γ-Al2O3 process could be divided into microwave induction stage and catalytic oxidation stage, both of which fitted first-order kinetics, with reaction rate constants of 0.0453 min-1 and 4.7552 min-1 respectively.


2014 ◽  
Vol 13 (1) ◽  
Author(s):  
Dariusz Wyrzykowski ◽  
Joanna Pranczk ◽  
Dagmara Jacewicz ◽  
Aleksandra Tesmar ◽  
Bogusław Pilarski ◽  
...  

AbstractA potentiometric titration method (PT) and a stopped-flow kinetic technique monitored by a UV−Vis spectroscopy have been used to characterize the stability of series of Co(II)- and Ni(II)-thiodiacetato complexes, M(TDA), in the presence of 1,10-phenanthroline (phen) or 2,2’-bipyridine (bipy) in aqueous solutions. The stability constants of the binary (1:1), ternary (1:1:1) as well as the resulting hydroxo complexes were evaluated and compared to the corresponding oxydiacetate complexes. Based on the species distribution as a function of pH the relative predominance of the species in the system over a pH range was discussed. Furthermore, the kinetic measurements of the substitution reactions of the aqua ligands to phen or bipy in the coordination sphere of the binary complexes M(TDA) were performed in the 288–303 K temperature range, at a constant concentration of phen or bipy and at seven different concentrations of the binary complexes (0.2–0.5 mM). The kinetic stability of the M(TDA) complexes was discussed in relation to the experimental conditions and the kind of the auxiliary ligands (phen/bipy). Moreover, the influence of the type of primary ligand (thiodiacetate/oxydiacetate) on the substitution rate of the auxiliary ligands was also compared.


2016 ◽  
Vol 54 (1) ◽  
pp. 37-52 ◽  
Author(s):  
I Eceiza ◽  
L Irusta ◽  
A Barrio ◽  
MJ Fernández-Berridi

Novel isophorone diisocyanate-based flexible polyurethane foams were prepared by the one-step method in a computerized foam qualification system (FOAMAT). The experimental conditions to obtain this type of foams, in relation to the nature and concentration of catalysts as well as the reaction temperature, were established as no data were available in scientific literature. The chemical reactions occurring during the foam generation process were monitored in situ by attenuated total reflectance-FTIR spectroscopy. The kinetics of the foam generation was fitted to an nth order model and the data showed that the foaming process adjusted to a first-order kinetics. The physical changes as pressure, foam height, and dielectric polarization were monitored by the FOAM software (FOAMAT). According to these parameters, the foaming process was divided into four steps: bubble growth, bubble packing, cell opening, and final curing.


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