scholarly journals Exploration of the H2O2 Oxidation Process and Characteristic Evaluation of Humic Acids from Two Typical Lignites

ACS Omega ◽  
2021 ◽  
Author(s):  
Miao Wang ◽  
Yanhong Li ◽  
Yuanqin Zhang ◽  
Xun Hu ◽  
Qingyin Li ◽  
...  
RSC Advances ◽  
2015 ◽  
Vol 5 (71) ◽  
pp. 57444-57452 ◽  
Author(s):  
Jianguo Liu ◽  
Changjin Ou ◽  
Weiqing Han ◽  
Faheem Faheem ◽  
Jinyou Shen ◽  
...  

In this study, an integrated system comprised of zero-valent iron (ZVI) reduction and ZVI-based Fenton oxidation was applied for the selective removal of nitroaromatic compounds from 2,4-dinitroanisole producing wastewater.


2001 ◽  
Vol 43 (10) ◽  
pp. 311-318 ◽  
Author(s):  
M. Yang ◽  
Y. Zhang ◽  
R. Qi ◽  
K. Uesugi ◽  
H. Myoga

A continuous two step O3/H2O2 oxidation system, in which the waste gas from the former reactor was reused in the latter step with an ejector, was established for the purpose of wastewater reclamation in electronics industries. ORP monitor was combined into the system to obtain the optimum ratio of H2O2 to O3 by automatically adjusting the dosage of H2O2, and ion exchange resin was used for removing organic acids formed during oxidation. The effectiveness of the O3/H2O2 oxidation system for TOC removal was investigated under various conditions by using IPA, DMSO, and NMP as model substances. The optimum H2O2/O3 for oxidizing IPA was in a range above 0.15, and it increased with the increase of O3 dose. A sudden drop of ORP from ca. 800 mV to a little more than 200 mV was observed when H2O2/O3 was approaching the optimum point from the lower end. An ORP between 250 mV and 300mV or 800 mV and 900 mV was proper for H2O2/O3 control. The treatability of the model substances was in an order of IPA<<DMSO<NMP, being consistent with the magnitude of the energy of the highest occupied molecular orbital (eHOMO). The two step treatment system developed in this study was found to be more efficient than the conventional single step system. With the help of H2O2 dosing control and two step treatment using waste O3, the system could save about 40% O3 in comparison with the conventional O3/H2O2 oxidation process.


2010 ◽  
Vol 33 ◽  
pp. 327-331 ◽  
Author(s):  
Cheng Liu ◽  
Wei Chen ◽  
Man Wang ◽  
Zhe Cao

The removal efficiency of microcystin-LR in water and the influencing factors by combined process of solar irradiation and S-doped TiO2 were studied in detail, in which S-doped TiO2 photo-catalyst with high sunlight activity was prepared by acid catalyzed hydrolysis method using thiourea as sulfur source. The experiment results showed that MC-LR could be more effectively oxidized by the solar/S-doped TiO2 process than by solar/ TiO2 process, whose removal effect were about 70% and 55% after 40 min’s irradiation, respectively. Pseudo-first-order model could be used to simulate the oxidation process. Degradation rate could be greatly affected by the concentration of H2O2, the optimum concentration for the system of solar/S-doped TiO2 was found to be 20mg/L, which was 5mg/L higher than that of solar/TiO2 system. Humic acids decreased the degradation rate, and solar/S-doped TiO2 process more easily affected, for the humic acids could not only compete with molecular MC-LR for radicals but also adsorb part of sunlight which can excite radical with TiO2.


2001 ◽  
Vol 44 (5) ◽  
pp. 287-293 ◽  
Author(s):  
D. Grossmann ◽  
H. Köser ◽  
R. Kretschmer ◽  
M. Porobin

Diglyme (CAS No. 111-96-6), a biorefractive ether with teratogenic properties is of considerable importance as a solvent in the synthetic chemical industry. Results of lab-scale investigations into the optimal conditions for the oxidative mineralisation of 0.05 to 1 g/L of diglyme in synthetic process waters by hydrogen peroxide and ozone based advanced oxidation processes are presented. Fenton, photo-assisted Fenton and UV/H2O2 oxidation processes show acceptable TOC removals. At 50°C the initial TOC removal rates varies between 0.07 and 6g TOC/L*h. The rates increase with the initial diglyme and hydrogen peroxide concentration as well as with the UV irradiation energy intensity. For example at a 1g/l diglyme concentration a stoichiometric H2O2 addition resulted in TOC degradation of 60% to 70% after 30 minutes under the investigated conditions. Treatment with ozone/H2O2 at a pH of 8 and 25°C required at least 100 minutes to achieve comparable mineralisation results. Biodegradability can be reached in far shorter times. Ozone on its own cannot be recommended for diglyme treatment. If complete mineralisation of diglyme is the objective, the UV/H2O2 oxidation process should be favoured. The ozone/H2O2 process might offer a viable alternative in cases where the oxidation step is followed by biological wastewater treatment, so that biodegradability is aimed at.


2021 ◽  
Vol 25 (01) ◽  
pp. 59-67
Author(s):  
Hanadi A. Mohammed ◽  
◽  
Seroor A. Khaleefa ◽  
Mohammed I. Basheer ◽  
◽  
...  

Photolysis of methylene blue was studied by using an advanced UV/H2O2 oxidation process. This study investigated different initial dye concentrations (I0, 20, 30 ppm) using different concentrations of H2O2 (10 %, 30%, 50 %) in three additions (5 mL, 10 mL, 15 mL). The results showed that the degradation efficiencies of this dye at different concentrations were as follows: 99.86 % at 10 ppm using 15 mL of 10 % H2O2 after 60 min, 99.22 % at 20 ppm using 15 mL of 30 % H2O2 for 60 min, and 98.90 % at 30ppm using 15 mL of 50 % H2O2 after 90 min. An increase in the optimum concentration of H2O2 was observed with an increase in the initial dye concentration. The de-coloration time also increased with increasing initial dye concentration.


2020 ◽  
Vol 14 (2) ◽  
pp. 123-130
Author(s):  
Rouhollah Shokri ◽  
◽  
Reza Jalilzadeh Yengejeh ◽  
Ali Akbar Babaei ◽  
Ehsan Derikvand ◽  
...  

Background: Antibiotics are considered important and integral parts of modern life, and are widely used for treating human and animal illnesses, in medicine and veterinary medicine. However, they can cause environmental pollution and may lead to increased bacterial resistance even at low concentrations. Methods: In this study, Ampicillin degradation from β-lactam antibiotic family was studied, using a surface methodology consisting of ultraviolet radiation (254 nm) and H2O2 oxidation process in an 8-watt Pyrex reactor. The variables used included the reaction time (30-60 min), Ampicillin concentration (5-25 mg/l), H2O2 concentration (5-25 mg/l), and pH range of 3-9 at three alpha levels of -1, 0 and +1. Results: The data were analyzed by the analysis of variance test (ANOVA), while the validity was evaluated using regression coefficients. The optimum condition for Ampicillin degradation followed a linear model, at a 60-min. reaction time and pH 3, the Ampicillin (5mg/l) and hydrogen peroxide (25mg/l) provided the maximum antibiotic removal efficiency (82%). Conclusions: The results suggest a positive and significant effect for the antibiotic concentration and a negative effect for the pH. The Ampicillin concentration with a coefficient of 8.91 had the highest impact on the efficiency of the removal process. Therefore, antibiotic pollution in the environment can be reduced through the UV-H2O2 process, so as to protect human health from the associated hazards.


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