Radicals induced from peroxomonosulfate by nanoscale zero-valent copper in the acidic solution

2016 ◽  
Vol 74 (8) ◽  
pp. 1946-1952 ◽  
Author(s):  
Peng Zhou ◽  
Bei Liu ◽  
Jing Zhang ◽  
Yongli Zhang ◽  
Gucheng Zhang ◽  
...  
Keyword(s):  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Acidic Solution ◽  
Butyl Alcohol ◽  
First Order ◽  
First Order Kinetics ◽  
Tert Butyl Alcohol ◽  
Initial Ph ◽  
Reactive Radicals ◽  
Reactive Oxidant

A highly efficient advanced oxidation process for the degradation of benzoic acid (BA) during activation of peroxomonosulfate (PMS) by nanoscale zero-valent copper (nZVC) in acidic solution is reported. BA degradation was almost completely achieved after 10 min in the nZVC/PMS process at initial pH 3.0. PMS could accelerate the corrosion of nZVC in acidic to release Cu+ which can further activate PMS to produce reactive radicals. Both sulfate radical (SO4−•) and hydroxyl radical (•OH) were considered as the primary reactive oxidant in the nZVC/PMS process with the experiments of methyl (MA) and tert-butyl alcohol quenching. Acidic condition (initial pH ≤ 3.0) facilitated BA degradation and pH is a decisive factor to affect the oxidation capacity in the nZVC/PMS process. Moreover, BA degradation in the nZVC/PMS process followed the pseudo-first-order kinetics, and BA degradation efficiency increased with the increase of the nZVC dosage.

scholarly journals Cyanide Containing Wastewater Treatment by Ozone Enhanced Catalytic Oxidation over Diatomite Catalysts

2018 ◽  
Vol 142 ◽  
pp. 01003
Author(s):  
Mingguo Lin ◽  
Qiyuan Gu ◽  
Xinglan Cui ◽  
Xingyu Liu
Keyword(s):  
Catalytic Oxidation ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Removal Rate ◽  
Order Rate Constant ◽  
Alkaline Condition ◽  
First Order ◽  
First Order Kinetics ◽  
Initial Ph ◽  
The One

Cyanide containing wastewater that discharged from gold mining process creates environmental problems due to the toxicity of cyanide. As one of the promising advanced oxidation process, catalytic oxidation with ozone is considered to be effective on the purification of cyanide. Diatomite, a natural mineral, was used as catalyst in this study. The effect of O3 dosage, salinity, initial cyanide concentration and initial pH condition were investigated. It was observed that the removal rate of cyanide was much higher in the catalytic oxidation with ozone process than the one in zone alone process. Alkaline condition was especially favorable for cyanide in catalytic oxidation with ozone. The ozone and catalytic oxidation with ozone were simulated by pseudo-first-order kinetics model. The apparent first-order rate constant contribution of the diatomite catalyst was 0.0757 min-1, and the contribution percentage was 65.77%.

Kinetic of C.I. Reactive Black 5 by Fenton-Like Oxidation

2013 ◽  
Vol 690-693 ◽  
pp. 1512-1515
Author(s):  
Yi Jun Du ◽  
Guo Peng Jiang ◽  
Xin Ping Fang ◽  
Mu Qing Qiu
Keyword(s):  
Reaction Temperature ◽  
Oxidation Process ◽  
Solution Concentration ◽  
Operating Parameters ◽  
Reactive Black 5 ◽  
H2o2 Concentration ◽  
System Parameters ◽  
First Order ◽  
First Order Kinetics ◽  
Initial Ph

The decolorization kinetic of C.I. Reactive Black 5 was studied using Fenton-like oxidation. The effect of the major system parameters, such as initial pH of the solution, concentration of H2O2, concentration of Fe3+ and reaction temperature on the kinetics was determined. The results indicate that the operating parameters, such as initial pH of dye solution, initial concentration of Fe2+ and H2O2, reaction temperature, have strong influences on the degradation of C.I. Reactive Black 5 by Fenton-like oxidation process. In addition, it was also found that the decolorization of C.I. Reactive Black 5 followed the first-order kinetics well.

scholarly journals Degradation of Paracetamol by an UV/Chlorine Advanced Oxidation Process: Influencing Factors, Factorial Design, and Intermediates Identification

2018 ◽  
Vol 15 (12) ◽  
pp. 2637 ◽  
Author(s):  
Yen Dao ◽  
Hai Tran ◽  
Thien Tran-Lam ◽  
Trung Pham ◽  
Giang Le
Keyword(s):  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
High Resolution Mass Spectrometry ◽  
Advanced Oxidation ◽  
Transformation Products ◽  
Solution Ph ◽  
Operational Conditions ◽  
First Order ◽  
First Order Kinetics ◽  
Degradation Rate Constant

The combination of a low-pressure mercury lamp and chlorine (UV/chlorine) was applied as an emerging advanced oxidation process (AOP), to examine paracetamol (PRC) degradation under different operational conditions. The results indicated that the UV/chlorine process exhibited a much faster PRC removal than the UV/H2O2 process or chlorination alone because of the great contribution of highly reactive species (•OH, •Cl, and ClO•). The PRC degradation rate constant (kobs) was accurately determined by pseudo-first-order kinetics. The kobs values were strongly affected by the operational conditions, such as chlorine dosage, solution pH, UV intensity, and coexisting natural organic matter. Response surface methodology was used for the optimization of four independent variables (NaOCl, UV, pH, and DOM). A mathematical model was established to predict and optimize the operational conditions for PRC removal in the UV/chlorine process. The main transformation products (twenty compound structures) were detected by liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS).

Kinetics of Pumice Catalyzed Ozonation of Trace p-Chloronitrobenzene in Aqueous Solution

2011 ◽  
Vol 90-93 ◽  
pp. 2925-2928 ◽  
Author(s):  
Lei Yuan ◽  
Ji Min Shen ◽  
Zhong Lin Chen
Keyword(s):  
Aqueous Solution ◽  
Rate Constant ◽  
Butyl Alcohol ◽  
Order Kinetic ◽  
First Order ◽  
Highly Active ◽  
Tert Butyl Alcohol ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Kinetics Of

The kinetics of pumice for decomposition of p-chloronitrobenzene (pCNB) in aqueous solution were investigate. The experiment result indicated that ozonation alone and pumice-catalyzed ozonation of trace pCNB in aqueous solution followed the Pseudo-first-order kinetic model at the reaction temperature of 296 K and the initial pH of 6.86. The rate constant of pumice-catalyzed ozonation increase 149% compared with ozonation alone. In two processes mentioned above, the rate constants of degradation of pCNB were found to decrease with increasing of tert-butyl alcohol. The rate constant of ozonation alone appeared to be decreased 73%, respectively, decreasing 194% in the process of pumice-catalyzed ozonation. Under the conditions of this experiment, ozonation alone and pumice-catalyzed ozonation for degradation of pCNB were primarily oxidized by highly active hydroxyl radicals.

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.

UV Based Advanced Oxidation Process for Degradation of Ciprofloxacin: Reaction Kinetics, Effects of Interfering Substances and Degradation Product Identification

2021 ◽  
Author(s):  
Bijoli Mondal ◽  
Shib Sankar Basak ◽  
Arnab Das ◽  
Sananda Sarkar ◽  
Asok Adak
Keyword(s):  
Organic Compounds ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Uv Light ◽  
Degradation Products ◽  
Irradiation Time ◽  
Advanced Oxidation ◽  
Quantum Yields ◽  
Photon Flux ◽  
First Order

Abstract In the photochemical UV-H2O2 advanced oxidation process, H2O2 absorbs UV light and is decomposed to form hydroxyl radicals (OH·), which are highly excited and reactive for electron-rich organic compounds and hence can degrade organic compounds. In the present work, the UV-H2O2 process was investigated to degrade ciprofloxacin (CIP), one of India's widely used antibiotics, from aqueous solutions using a batch type UV reactor having photon flux = 1.9 (± 0.1) ×10-4 Einstein L-1 min-1. The effects of UV irradiation time on CIP degradation were investigated for both UV and UV-H2O2 processes. It was found that about 75% degradation of CIP was achieved within 60 s with initial CIP concentration and peroxide concentration of 10 mg L-1 and 1 mol H2O2/ mol CIP, respectively, at pH of 7(±0.1) and fluence dose of 113 mJ cm-2. The experimental data were analyzed by the first-order kinetics model to find out the time- and fluence-based degradation rate constants. Under optimized experimental conditions (initial CIP concentration, pH and H2O2 dose of 10 mg L-1, 7(±0.1) and 1.0 mol H2O2 / mol CIP, respectively), the fluence-based pseudo-first-order rate constant for the UV and UV-H2O2 processes were determined to be 1.28(±0.0) ×10-4 and 1.20(±0.04) ×10-2 cm2 mJ-1 respectively. The quantum yields at various pH under direct UV were calculated. The impacts of different process parameters such as H2O2 concentration, solution pH, initial CIP concentration, and wastewater matrix on CIP degradation were also investigated in detail. CIP degradation was favorable in acidic conditions. Six degradation products of CIP were identified. Results clearly showed the potentiality of the UV-H2O2 process for the degradation of antibiotics in wastewater.

THE DECOMPOSITION OF SILYL PEROXIDES

1964 ◽  
Vol 42 (5) ◽  
pp. 985-989 ◽  
Author(s):  
Richard R. Hiatt
Keyword(s):  
Thermal Decomposition ◽  
Rate Constant ◽  
Half Life ◽  
Order Rate Constant ◽  
Butyl Alcohol ◽  
Base Catalysis ◽  
First Order ◽  
Tert Butyl ◽  
Tert Butyl Alcohol ◽  
Acid And Base

The thermal decomposition of tert-butyl trimethylsilyl peroxide has been investigated and found to be sensitive to acid and base catalysis and to the nature of the solvent. In heptane and iso-octane the first-order rate constant could be expressed as 1.09 × 1015e−41200/RT and in 1-octene as 3.90 × 1015e−41200/RT (sec−1). The half life at 203 °C was about 1 hour. The reaction was faster in aromatic solvents; in chlorobenzene it was complicated by formation of HCl from the solvent.Products of the reaction were acetone, tert-butyl alcohol and hexamethyldisiloxane.

Superiority of solar Fenton oxidation over TiO2 photocatalysis for the degradation of trimethoprim in secondary treated effluents

2013 ◽  
Vol 67 (6) ◽  
pp. 1260-1271 ◽  
Author(s):  
I. Michael ◽  
E. Hapeshi ◽  
C. Michael ◽  
D. Fatta-Kassinos
Keyword(s):  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Heterogeneous Photocatalysis ◽  
Solar Irradiation ◽  
Fenton Process ◽  
Iron Salt ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Initial Substrate ◽  
Initial Substrate Concentration

The overall aim of this work was to examine the degradation of trimethoprim (TMP), which is an antibacterial agent, during the application of two advanced oxidation process (AOP) systems in secondary treated domestic effluents. The homogeneous solar Fenton process (hv/Fe2+/H2O2) and heterogeneous photocatalysis with titanium dioxide (TiO2) suspensions were tested. It was found that the degradation of TMP depends on several parameters such as the amount of iron salt and H2O2, concentration of TiO2, pH of solution, solar irradiation, temperature and initial substrate concentration. The optimum dosages of Fe2+ and H2O2 for homogeneous ([Fe2+] = 5 mg L−1, [H2O2] = 3.062 mmol L−1) and TiO2 ([TiO2] = 3 g L−1) for heterogeneous photocatalysis were established. The study indicated that the degradation of TMP during the solar Fenton process is described by a pseudo-first-order reaction and the substrate degradation during the heterogeneous photocatalysis by the Langmuir–Hinshelwood kinetics. The toxicity of the treated samples was evaluated using a Daphnia magna bioassay and was finally decreased by both processes. The results indicated that solar Fenton is more effective than the solar TiO2 process, yielding complete degradation of the examined substrate within 30 min of illumination and dissolved organic carbon (DOC) reduction of about 44% whereas the respective values for the TiO2 process were ∼70% degradation of TMP within 120 min of treatment and 13% DOC removal.

scholarly journals Removing The Acid Orange 12 Azo Dye from Aqueous Solution Using Sodium Hypochlorite, A Kinetic and Thermodynamic Study

2022 ◽  
Vol 961 (1) ◽  
pp. 012056
Author(s):  
A. B. Hameed ◽  
A. B. Dekhyl ◽  
W. M. Sh. Alabdraba
Keyword(s):  
Removal Efficiency ◽  
Sodium Hypochlorite ◽  
Azo Dye ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Batch Reactor ◽  
Solution Temperature ◽  
Acid Orange ◽  
Initial Ph ◽  
Time Required

Abstract This study investigated the feasibility of using sodium hypochlorite as an advanced oxidation process to remove Acid Orange 12 azo dye from wastewater. For this purpose, batch reactor experiments were done. Several variables to address the efficiency of using this process were considered. These variables are initial pH (5, 7, and 9), the concentration of hypochlorite (50 – 250 mg/l), temperature (20-50) degrees Celsius, and time of electrolysis (1-75) min. also investigate the effects of UV on the process was done. Experimental results showed that the color removal efficiency using NaOCl with UV is more effective than NaOCl alone. The highest removal efficiency was obtained by increasing the concentration of NaOCl from (50-250mg/l) at PH=5. When the solution temperature was increased from (20-50) °C, the removal efficiency increased, and at the same time, the time required was reduced from (20-5) minutes to obtain the highest removal efficiency. The kinetic study also showed that the oxidation process follows a second-order reaction. The thermodynamic functions indicate that the response is spontaneous, endothermic, and increases randomness.

scholarly journals Hydrothermal synthesis of magnetic nano-CoFe2O4 catalyst and its enhanced degradation of amoxicillin by activated permonosulfate

2021 ◽  
Author(s):  
Xiaoyan Li ◽  
Hongwei Wang ◽  
Guozhen Zhang ◽  
Tianhong Zhou ◽  
Fuping Wu
Keyword(s):  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Ph Value ◽  
Engineering Application ◽  
Degradation Pathway ◽  
Active Species ◽  
Initial Ph ◽  
Practical Engineering ◽  
Low Efficiency ◽  
Polluted Wastewater

Abstract Advanced oxidation process (AOP) has attracted widespread attention because it can effectively remove antibiotics in water, but its practical engineering application is limited by the problems of the low efficiency and difficult recovery of the catalyst. In the study, nano-spinel CoFe2O4 was prepared by hydrothermal method and served as the peroxymonosulfate (PMS) catalyst to degrade antibiotic amoxicillin (AMX). The reaction parameters such as CoFe2O4 dosage, AMX concentration, and initial pH value were also optimized. The reaction mechanism was proposed through free radical capture experiment and possible degradation pathway analysis. In addition, the magnetic recovery performance and stability of the catalyst were evaluated. Results showed that 85.5% of AMX could be removed within 90 min at optimal conditions. Sulfate radicals and hydroxyl radicals were the active species for AMX degradation. Moreover, the catalyst showed excellent magnetism and stability in the cycle experiment, which has great potential in the AOP treatment of antibiotic polluted wastewater.

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