scholarly journals Impact of Active Chlorines and •OH Radicals on Degradation of Quinoline Using the Bipolar Electro-Fenton Process

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 128
Author(s):  
Wenlong Zhang ◽  
Jun Chen ◽  
Jichao Wang ◽  
Cheng-Xing Cui ◽  
Bingxing Wang ◽  
...  
Keyword(s):  
Degradation Kinetics ◽  
Degradation Mechanism ◽  
Supporting Electrolyte ◽  
Reaction System ◽  
Oxygen Demand ◽  
Oh Radicals ◽  
Fenton Process ◽  
Reaction Conditions ◽  
Initial Ph ◽  
Kinetics Of

Quinoline is a typical nitrogenous heterocyclic compound, which is carcinogenic, teratogenic, and mutagenic to organisms, and its wastewater is difficult to biodegrade directly. The bipolar electro-Fenton process was employed to treat quinoline solution. The process/reaction conditions were optimized through the single factor experiment. The degradation kinetics of chemical oxygen demand (COD) was analyzed. To get the degradation mechanism and pathways of quinoline, the intermediate products were identified by gas chromatograph–mass spectrometer (GC–MS). By using sodium chloride as supporting electrolyte in the electro-Fenton reaction system with initial pH 3.0, conductivity 15,800 µs/cm, H2O2 concentration 71 mmol/L, current density 30.5 mA/cm2, and applied voltage 26.5 V, 75.56% of COD was decreased by indirect oxidation with electrogeneration of hydroxyl radicals (•OH) and active chloric species in 20 min. The COD decrease of quinoline solution followed the first order reaction kinetic model. The main products of quinoline degradation were 2(1H)-quinolinone, 4-chloro-2(1H)-quinolinone, 5-chloro-8-hydroxyquinoline, and 5,7-dichloro-8-hydroxyquinoline. Furthermore, two possible degradation pathways of quinoline were proposed, supported with Natural charge distribution on quinoline and intermediates calculated at the theoretical level of MN15L/6-311G(d).

scholarly journals Efficient Degradation of Mordant Blue 9 Using the Fenton-Activated Persulfate System

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2532 ◽  
Author(s):  
Md. Nahid Pervez ◽  
Felix Y. Telegin ◽  
Yingjie Cai ◽  
Dongsheng Xia ◽  
Tiziano Zarra ◽  
...  
Keyword(s):  
Butyl Alcohol ◽  
Textile Dye ◽  
Oh Radicals ◽  
Operational Parameters ◽  
Reaction Conditions ◽  
Tert Butyl Alcohol ◽  
Initial Ph ◽  
Fe Complex ◽  
Optimal Reaction ◽  
Activated Persulfate

In this study, a Fenton-activated persulfate (Fe2+/PS) system was introduced for the efficient degradation of Mordant Blue 9 (MB 9) as a textile dye in an aqueous solution. Results showed that the degradation of MB 9 was markedly influenced by operational parameters, such as initial pH, PS concentration, Fe2+ concentration, and initial dye concentration. Optimal reaction conditions were then determined. Inorganic anions, such as Cl− and HCO3−, enhanced the degradation efficiency of MB 9 under optimal conditions. Addition of HCO3− reduced the degradation performance of MB 9, whereas the addition of Cl− increased the degradation percentage of MB 9. In addition, quenching experiments were conducted using methanol and tert-butyl alcohol as scavengers, and methanol was identified as an effective scavenger. Thus, the degradation of MB 9 was attributed to S O 4 • − and •OH radicals. The degradation and mineralization efficiency of MB 9 was significantly reduced using the conventional Fenton process i.e., Fe2+/ hydrogen peroxide (HP) because of the formation of a Fe complex during degradation. Meanwhile, the Fe2+/persulfate (PS) system improved the degradation and mineralization performance.

scholarly journals Laboratory study on OH-initiated degradation kinetics of dehydroabietic acid

2015 ◽  
Vol 17 (16) ◽  
pp. 10953-10962 ◽  
Author(s):  
Chengyue Lai ◽  
Yongchun Liu ◽  
Jinzhu Ma ◽  
Qingxin Ma ◽  
Hong He
Keyword(s):  
Laboratory Study ◽  
Environmental Conditions ◽  
Degradation Kinetics ◽  
Dehydroabietic Acid ◽  
Oh Radicals ◽  
Kinetics Of

The degradation kinetics of dehydroabietic acid by OH radicals were investigated under various environmental conditions.

scholarly journals Optimization Parameters, Kinetics and Mechanism of Naproxen Removal by Catalytic Wet Peroxide Oxidation with a Hybrid Iron-Based Magnetic Catalyst

Catalysts ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 287 ◽  
Author(s):  
Ysabel Huaccallo-Aguilar ◽  
Silvia Álvarez-Torrellas ◽  
Marcos Larriba ◽  
V. Ismael Águeda ◽  
José Antonio Delgado ◽  
...  
Keyword(s):  
Degradation Kinetics ◽  
Degradation Mechanism ◽  
Treatment Plant ◽  
Operating Conditions ◽  
Surface Model ◽  
Oh Radicals ◽  
Order Kinetic ◽  
Peroxide Oxidation ◽  
Wet Peroxide Oxidation ◽  
Catalytic Wet Peroxide Oxidation

This work presents a study of the assessment of the operating parameters of the catalytic wet peroxide oxidation (CWPO) of naproxen (NAP) using magnetite/multi-walled carbon nanotubes (Fe3O4/MWCNTs) as a catalyst. The effect of pH, temperature, and H2O2 dosage on CWPO process was evaluated by using the response surface model (RSM), allowing us to obtain an optimum NAP removal of 82% at the following operating conditions: pH = 5, T = 70 °C, [H2O2]0 = 1.5 mM, and [NAP]0 = 10.0 mg/L. Therefore, NAP degradation kinetics were revealed to follow a pseudo-second-order kinetic model, and an activation energy value of 4.75 kJ/mol was determined. Adsorption and using only H2O2 experiments, both considered as blank tests, showed no significant removal of the pollutant. Moreover, Fe3O4/MWCNTs material exhibited good recyclability along three consecutive cycles, finding an average NAP removal percentage close to 80% in each cycle of 3 h reaction time. In addition, the scavenging tests confirmed that the degradation of NAP was mainly governed by •OH radicals attack. Two reaction sequences were proposed for the degradation mechanism according to the detected byproducts. Finally, the versatility of the catalyst was evidenced in the treatment of different environmentally relevant aqueous matrices (wastewater treatment plant effluent (WWTP), surface water (SW), and a hospital wastewater (HW)) spiked with NAP, obtaining total organic carbon (TOC) removal efficiencies after 8 h in the following order: NAP-SW > NAP-HW > NAP-WWTP.

scholarly journals Optimization of the Photochemical Degradation of Textile Dye Industrial Wastewaters

2017 ◽  
Vol 33 (1) ◽  
pp. 10 ◽  
Author(s):  
T.H. Dang ◽  
T.P. Mai ◽  
M.T. Truong ◽  
L.T Dao ◽  
T.A.N Nguyen
Keyword(s):  
Design Methodology ◽  
Oxygen Demand ◽  
Textile Dye ◽  
Photochemical Degradation ◽  
Fenton Process ◽  
Optimal Conditions ◽  
Industrial Wastewaters ◽  
Independent Variables ◽  
Initial Ph ◽  
Experimental Design Methodology

In this study, the photochemical degradation via photo-Fenton process was carried out to degrade dyes in textile industrial wastewaters. Experimental design methodology was also applied for optimizing effects of factors which influencethe effective treatment such as ferric dose, hydroperoxide dosage, initial pH, reaction time and initial chemical oxygen demand (COD). Two independent variables namely colour and COD removal efficiencieswere used to evaluate the treatment yield. Under the optimal conditions, ca. 99%  and ca. 88%, colour, and COD were removed, respectively.

scholarly journals Highly efficient UV/H2O2 technology for the removal of nifedipine antibiotics: Kinetics, co-existing anions and degradation pathways

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258483
Author(s):  
Wenping Dong ◽  
Chuanxi Yang ◽  
Lingli Zhang ◽  
Qiang Su ◽  
Xiaofeng Zou ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Degradation Rate ◽  
Degradation Kinetics ◽  
Degradation Pathways ◽  
Oxygen Species ◽  
Highly Efficient ◽  
Initial Ph ◽  
Primary Key ◽  
Kinetics Of

This study investigates the degradation of nifedipine (NIF) by using a novel and highly efficient ultraviolet light combined with hydrogen peroxide (UV/H2O2). The degradation rate and degradation kinetics of NIF first increased and then remained constant as the H2O2 dose increased, and the quasi-percolation threshold was an H2O2 dose of 0.378 mmol/L. An increase in the initial pH and divalent anions (SO42- and CO32-) resulted in a linear decrease of NIF (the R2 of the initial pH, SO42- and CO32- was 0.6884, 0.9939 and 0.8589, respectively). The effect of monovalent anions was complex; Cl- and NO3- had opposite effects: low Cl- or high NO3- promoted degradation, and high Cl- or low NO3- inhibited the degradation of NIF. The degradation rate and kinetics constant of NIF via UV/H2O2 were 99.94% and 1.45569 min-1, respectively, and the NIF concentration = 5 mg/L, pH = 7, the H2O2 dose = 0.52 mmol/L, T = 20 ℃ and the reaction time = 5 min. The ·OH was the primary key reactive oxygen species (ROS) and ·O2- was the secondary key ROS. There were 11 intermediate products (P345, P329, P329-2, P315, P301, P274, P271, P241, P200, P181 and P158) and 2 degradation pathways (dehydrogenation of NIF → P345 → P274 and dehydration of NIF → P329 → P315).

scholarly journals Electrochemical Degradation of Crystal Violet Using Ti/Pt/SnO2 Electrode

2021 ◽  
Vol 11 (18) ◽  
pp. 8401
Author(s):  
Rachid El Brychy ◽  
Mohamed Moutie Rguiti ◽  
Nadia Rhazzane ◽  
Moulay Driss Mellaoui ◽  
Khalid Abbiche ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Crystal Violet ◽  
Current Density ◽  
Ph Value ◽  
Supporting Electrolyte ◽  
Chloride Concentration ◽  
Oxygen Demand ◽  
Electrochemical Treatment ◽  
Electrochemical Process ◽  
Initial Ph

Today, organic wastes (paints, pigments, etc.) are considered to be a major concern for the pollution of aqueous environments. Therefore, it is essential to find new methods to solve this problem. This research was conducted to study the use of electrochemical processes to remove organic pollutants (e.g., crystal violet (CV)) from aqueous solutions. The galvanostatic electrolysis of CV by the use of Ti/Pt/SnO2 anode, were conducted in an electrochemical cell with 100 mL of solution using Na2SO4 and NaCl as supporting electrolyte, the effect of the important electrochemical parameters: current density (20–60 mA cm−2), CV concentration (10–50 mg L−1), sodium chloride concentration (0.01–0.1 g L−1) and initial pH (2 to 10) on the efficiency of the electrochemical process was evaluated and optimized. The electrochemical treatment process of CV was monitored by the UV-visible spectrometry and the chemical oxygen demand (COD). After only 120 min, in a 0.01mol L−1 NaCl solution with a current density of 50 mA cm−2 and a pH value of 7 containing 10 mg L−1 CV, the CV removal efficiency can reach 100%, the COD removal efficiency is up to 80%. The process can therefore be considered as a suitable process for removing CV from coloured wastewater in the textile industries.

scholarly journals Impact of Hydrogen Peroxide on the UVC Photolysis of Diclofenac and Toxicity of the Phototransformation Products

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Stanisław Ledakowicz ◽  
Emilia Drozdek ◽  
Tomasz Boruta ◽  
Magdalena Foszpańczyk ◽  
Magdalena Olak-Kucharczyk ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Vibrio Fischeri ◽  
Reaction System ◽  
Oxidation Products ◽  
Oh Radicals ◽  
Direct Photolysis ◽  
Depth Analysis ◽  
Comprehensive Comparison ◽  
Kinetics Of ◽  
Very High

The aim of this study was to investigate the effect of hydrogen peroxide on the UVC photolysis of diclofenac (DCF) in aqueous solution. The experimental results confirmed very high effectivity of UVC direct photolysis of diclofenac. Moreover, it was found that H2O2/UV only slightly improved photodegradation; however, the addition of hydrogen peroxide into the reaction system affected the mechanism of DCF decomposition. Kinetics of the DCF reaction with ⋅OH radicals in the UV/H2O2 process was determined. For both processes, namely, photolysis and UV/H2O2, an in-depth analysis focused on the formation of phototransformation products of DCF (TPs) was performed. To the best of our knowledge, such comprehensive comparison of diclofenac photodegradation via UVC photolysis and UV/H2O2 has not been presented so far. Although there were no significant differences with regard to the rate of diclofenac degradation by photolysis and UV/H2O2, different oxidation products were found to be associated with the two considered processes. Furthermore, the H2O2/UV treatment increased toxicity towards Vibrio fischeri, while direct UVC photolysis had no significant effect on toxicity. The increase in toxicity can be attributed to the breakdown of DCF and formation of much more toxic TPs in the course of the H2O2/UVC process.

scholarly journals Kinetics of Micellar Effect of Non-Ionic Surfactant on Oxidative Degradation of Ciprofloxacin

2019 ◽  
Vol 32 (2) ◽  
pp. 359-368
Author(s):  
Ajaya Kumar Singh ◽  
Alpa Shrivastava ◽  
Dilip R. Shrivastava ◽  
Rajmani Patel ◽  
Neerja Sachdev
Keyword(s):  
Degradation Kinetics ◽  
Oxidative Degradation ◽  
Activation Parameters ◽  
Solvent Polarity ◽  
Degradation Process ◽  
Oxidation Products ◽  
Ionic Surfactant ◽  
Reaction Conditions ◽  
Chloramine T ◽  
Kinetics Of

Oxidative degradation kinetics of leading fluoroquinolone family drug ciprofloxacin (CIP) by chloramine-T (CAT) in TX-100 micelle media was studied spectrophotometrically at 275 nm and 298 K. In pseudo-first-order conditions the rate constant (kobs) decreased regularly with increasing [TX-100]. To understand the self-organizing activities of TX-100, CMC values in varying reaction conditions had been evaluated. The role of non-ionic surfactant in the oxidative degradation process of ciprofloxacin by chlorinating agent chloramine-T is explained in terms of mathematical model explained by Menger-Portnoy. The reaction showed first to zero order dependence on [CAT] and fractional order on [CIP]. Increasing [H+] decreased the rate of reaction. The effect of ionic strength and solvent polarity of the medium in reaction conditions were studied. The effects of added salts [HSO4Na], [KCl], [KNO3] and [K2SO4] had also been studied. The stoichiometry of the reaction determined was 1:2 and the oxidation products were identified by LC-EI-MS. The analysis of degradation product of ciprofloxacin evidently reveals that the piperazine moiety is active site for oxidation in the reaction. Activation parameters were studied to propose appropriate mechanism for the reaction.

The Degradation Kinetics Study of Aromatic Organics with Different Functional Compounds on Anatase 001 Surface

NANO ◽  
2020 ◽  
Vol 15 (07) ◽  
pp. 2050087
Author(s):  
Zitao Ni ◽  
Wenzhong Fan ◽  
Tao Sun ◽  
Rongfei Wang ◽  
Jie Yang ◽  
...  
Keyword(s):  
Degradation Kinetics ◽  
Oxygen Demand ◽  
High Reactivity ◽  
Organic Species ◽  
Protection Technology ◽  
Potassium Hydrogen ◽  
New Type ◽  
Standard Solution ◽  
Intrinsic Degradation ◽  
Kinetics Of

Anatase TiO2 photocatalysts with exposed (001) facets have attracted great attention for environmental protection technology due to their high reactivity for degradation of organic species. In this work, potassium hydrogen phthalate (denoted as KHP), as the most commonly used reference standard solution for calibrating photoelectrochemical chemical oxygen demand (denoted as PeCOD) instrument, was selected as the study sample. The intrinsic degradation kinetics of KHP on (001) surface was investigated by a photoelectrochemical (denoted as PEC) method with a purposely (001) faceted double-layered structure TiO2 photoanode. The high kinetics constants of fast process of KHP and other acids indicate that the (001) surface possesses a higher reactivity of aromatic carboxylic acid as theoretically predicted. Meanwhile, the investigation of the KHP adsorption properties on A001 photoanode provides the possibility of using this photoanode as a sensor in a new type of PeCOD instrument for organic acid determination.

Sign in / Sign up

Export Citation Format

Share Document