scholarly journals UV-Enhanced NaClO Oxidation of Nitric Oxide from Simulated Flue Gas

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Shao-long Yang ◽  
Zhi-tao Han ◽  
Jing-ming Dong ◽  
Zi-sheng Zheng ◽  
Xin-xiang Pan
Keyword(s):  
Removal Efficiency ◽  
Uv Irradiation ◽  
Flue Gas ◽  
Ph Value ◽  
Irradiation Time ◽  
Reaction Chamber ◽  
Active Species ◽  
Chlorine Concentration ◽  
No Removal ◽  
Initial Ph

A wet de-NOxtechnique based on an UV-enhanced NaClO oxidation process was investigated for simulated flue gas of a diesel engine using a bench-scale reaction chamber. The effects of UV irradiation time, initial pH value, and available chlorine concentration of NaClO solution were studied, respectively. The results showed that when the UV irradiation time was 17.5 min and the initial pH value of NaClO solution was 6, NO removal efficiency of UV/NaClO solution was increased by 19.6% compared with that of NaClO solution. Meanwhile, when the available chlorine concentration of NaClO solution decreased from 0.1 wt% to 0.05 wt%, the enhancement in NO removal efficiency of UV/NaClO solution increased from 19.6% to 24%, compared with that of NaClO solution. The reaction pathways of NaClO solution photolysis and NO removal by UV/NaClO process were preliminarily discussed. The results suggested that HOCl might be the most active species that released many UV-induced photooxidants through photolysis reactions, which played an important role in NO removal process.

scholarly journals Application of response surface methodology for optimization of oxytetracycline hydrochloride degradation using hydrogen peroxide/polystyrene-supported iron phthalocyanine oxidation process

2020 ◽  
Vol 81 (6) ◽  
pp. 1308-1318
Author(s):  
Yue Sun ◽  
Xinlei Feng ◽  
Shun Fu
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Removal Efficiency ◽  
Ph Value ◽  
Axial Ligand ◽  
Active Species ◽  
Iron Phthalocyanine ◽  
Paramagnetic Resonance ◽  
Initial Ph ◽  
Novel Catalyst

Abstract Inspired by metalloporphyrin-based enzymes, a biomimetic catalyst, R-N-Fe, was prepared by grafting iron phthalocyanine (FePc) covalently onto a macroporous chloromethylated polystyrene-divinylbenzene resin (R), which was pre-functionalized using 4-aminopyridine (4-ampy) as an axial ligand. The novel catalyst was used for the degradation of oxytetracycline hydrochloride (OTCH). The response surface methodology was employed to optimize the independent operating parameters, including temperature, catalyst amount, H2O2 dosage, and initial pH value. The results displayed that the initial pH and temperature had the most significant effect on the removal efficiency. Under optimum conditions, the OTCH removal efficiency was 93.98%. Additionally, the classical quenching experiment and electron paramagnetic resonance (EPR) test indicated that R-N-Fe could generate hydroxyl radicals by decomposing H2O2, which was the main active species for eliminating OTCH. Furthermore, R-N-Fe can be easily recycled and can maintain high stability in the reusability test, rendering it a good potential for practical application.

Selection of Complex Adsobent and Catalytic Absorption NO from Flue Gas

2011 ◽  
Vol 322 ◽  
pp. 259-262
Author(s):  
Sheng Yu Liu ◽  
Li Chao Nengzi ◽  
Bing Qu ◽  
Yuan Yuan Xu ◽  
Wei Qiu ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Absorptive Capacity ◽  
Flue Gas ◽  
Ph Value ◽  
Complexing Agent ◽  
Catalytic Complex ◽  
No Removal ◽  
Cobalt Ion ◽  
Operation Parameter ◽  
Selection Of

In bubble reactor, the different complex adsorbents were used to adsorb NO. The results showed absorbent catalytic complex [Co(en)3]2+ formed by cobalt ion and en has good absorptive capacity to NO, removal efficiency can reach up to 90%.However complexing agent formed by EDTA has low capacity, only 20%-50%,and unstable. and the best adsobent was triethylenediamine cobalt ([Co(en)3]2+).pH value was an important operation parameter.

scholarly journals Comparison of sorption efficiency of natural and MnO2 coated zeolite for copper removal from model solutions

2021 ◽  
Vol 900 (1) ◽  
pp. 012003
Author(s):  
M Balintova ◽  
Z Kovacova ◽  
S Demcak ◽  
Y Chernysh ◽  
N Junakova
Keyword(s):  
Heavy Metals ◽  
Removal Efficiency ◽  
Ph Value ◽  
Batch Experiments ◽  
Modified Zeolite ◽  
Optimum Ph ◽  
Removal Of Heavy Metals ◽  
Initial Ph ◽  
Correlation Factors ◽  
Maximum Removal

Abstract Removal of heavy metals from the environment is important for living beings. The present work investigates the applicability of the natural and MnO2 - coated zeolite as sorbent for the removal of copper from synthetic solutions. Batch experiments were carried out to identify the influence of initial pH and concentration in the process of adsorption. A maximum removal efficiency of Cu(II) was observed in 10 mg/L for natural (95.6%) and modified (96.4%) zeolite, where the values was almost identical, but at concentration of 500 mg/L was the removal efficiency of modified zeolite three times higher. Based on the correlation factors R2, the Langmuir isotherms better describe the decontamination process than Freundlich. The optimum pH value was set at 5.0.

Study on the Experiments of Flue Gas Denitrification and Desulfurization Using Nitric Acid Solution

2008 ◽  
Author(s):  
Bao-Ming Sun ◽  
Shui-E Yin ◽  
Zhong-Li Wang
Keyword(s):  
Nitric Acid ◽  
Oxygen Concentration ◽  
Removal Efficiency ◽  
Flue Gas ◽  
Nitric Acid Concentration ◽  
Nox Removal ◽  
No Removal ◽  
Nox Removal Efficiency ◽  
The Individual ◽  
So2 Concentration

The present study attempts to take nitric acid as absorbent to clean up SO2 and NO gases simultaneously from the simulated flue gas in the lab-scale bubbling reactor, this study was divide into the individual DeNOx experiments and the combined DeSOx/DeNOx experiments: the individual DeNOx experiments were carried out to examine the effect of various operating parameters such as input NO concentration, nitric acid concentration, oxygen concentration input SO2 concentration, adding KMnO4 as additive and taking NaOH as the secondary absorption processes on the SO2 and NOx removal efficiencies at room temperature, the results of the individual DeNOx show that NO removal efficiency of 70%–95% were achieved under optimized conditions. NO removal efficiency increased with the increasing nitric acid concentration and increased by adding KMnO4 into the absorbent as additive as well. The removal efficiency of NO can reach 95% when using the two-step integrated processes of (HNO3+KMnO4)-NaOH, the absorption solution of 50% nitric acid, 400ppm of input NO concentration. 0.5% oxygen concentration and without SO2 in the simulated flue gas. No improvement on the NOx removal efficiency was observed with the increasing of KMnO4 and NaOH concentration in the scrubbing solution. The results of the combined DeSOx/DeNOx experiments show that the maximum DeNOx and DeSOx efficiencies ranged from 36.6% to 81% and from 99.4% to 100.0%, respectively. The prime parameters affecting the NOx removal efficiency are the oxygen concentration and the input SO2 concentration.

Effect of Environment Factors on Phosphorus Removal Efficiency of Phosphate Reduction System

2011 ◽  
Vol 255-260 ◽  
pp. 2797-2801
Author(s):  
Chen Yao ◽  
Chun Juan Gan ◽  
Jian Zhou
Keyword(s):  
Removal Efficiency ◽  
Phosphorus Removal ◽  
Ph Value ◽  
Removal Rate ◽  
Mass Rearing ◽  
Phosphate Removal ◽  
Environment Factors ◽  
Reduction System ◽  
Initial Ph ◽  
The Impact

Effect of environment factors such as initial pH value, dissolved oxygen (DO) and temperature on phosphorus removal efficiency of phosphate reduction system was discussed in treating pickled mustard tube wastewater. Results indicate that environment factors have significant influence on dephosphorization efficiency. And, the impact of DO on phosphate reduction is mainly by affecting the distribution of micro-environment inner biofilm, manifest as phosphate removal rate decreased with a fall in DO concentration, while overhigh DO can lead to detachment of biofilm, thus causing the increase of effluent COD concentration, and so DO need to be controlled in the range of 6 mg/L. Moreover, a higher temperature is more beneficial to phosphorus removal by PRB. Unfortunately, exorbitant temperature can result in mass rearing of Leuconostoc characterized with poor flocculability in reactor, and that cause turbidity in effluent appeared as a rise in COD of effluent. Hence, the optimal temperature is found to be about 30°C.

Evaluation of heterogeneous photo-Fenton oxidation of Orange II using response surface methodology

2010 ◽  
Vol 62 (6) ◽  
pp. 1320-1326 ◽  
Author(s):  
Y. H. Gong ◽  
H. Zhang ◽  
Y. L. Li ◽  
L. J. Xiang ◽  
S. Royer ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Heterogeneous Catalyst ◽  
Uv Irradiation ◽  
Heterogeneous Catalysts ◽  
Ph Value ◽  
Dye Degradation ◽  
High Catalytic Activity ◽  
Orange Ii ◽  
Initial Ph

A mesoporous SBA-15 doped iron oxide (Fe2O3/SBA-15) was synthesized by co-codensation, characterized and used as heterogeneous catalysts for the photo-Fenton decolorization of azo dye Orange II under UV irradiation. Response surface methodology (RSM) was used to investigate operating condition effects, such as hydrogen peroxide concentration, initial pH and catalyst loadings, on the decolorization rate. UV irradiation is found to enhance the activity of the catalyst in the process. RSM analysis evidenced the influence of the initial pH value and H2O2 concentration on the dye degradation rate. The coupled UV/Fe2O3/SBA-15/H2O2 process at room temperature is revealed as a promising friendly process for wastewater treatment. Indeed, the use of a heterogeneous catalyst allows an easy active phase recycling without multi-step recovering while the heterogeneous catalyst used here exhibits high catalytic activity for the reaction considered.

Removal of Sulfur Dioxide from Sintering Flue Gas with Coking Wastewater

2011 ◽  
Vol 287-290 ◽  
pp. 910-915
Author(s):  
Su Ju Hao ◽  
Wu Feng Jiang ◽  
Yu Zhu Zhang ◽  
Bing Liu
Keyword(s):  
Sulfur Dioxide ◽  
Removal Efficiency ◽  
Flue Gas ◽  
Ph Value ◽  
Coking Wastewater ◽  
Atmospheric Pollutant ◽  
Wastewater Treatment Process ◽  
Iron And Steel ◽  
On Line ◽  
Detection Instrument

Coking wastewater comprising a lot of ammonia is a good desulfurizer for recycling. Sintering flue gas is characterized by large volume, low sulfur dioxide (SO2) concentration and large variation amplitude and etc. The purpose for treating waste with waste can be carried out by treating sintering flue gas with coking wastewater. This paper uses a spray tower countercurrent device, ensures the contact between coking wastewater and sintering flue gas, and detects SO2 concentration of inlet flue gas and outlet flue gas on line by using an automatic flue gas detection instrument. This paper studies on the change regularity for the SO2 concentration at outlet flue gas during the process of treating sintering flue gas with coking wastewater, the influence of SO2 initial concentration in sintering flue gas to the removal efficiency of SO2, the influence of gas-liquid ratio between the sintering flue gas and the coking wastewater to the removal efficiency of SO2, and the change regularity for the pH value of coking wastewater after desulfurizing. The results show that the sintering flue gas which is treated can live up to the atmospheric pollutant effluent standard of iron and steel industry; the pH value of coking wastewater is reduced after treating, and the conditions for the implementation of subsequent coking wastewater treatment process are provided.

scholarly journals Degradation of Acid Red B by Manganese doped iron oxychloride and Permonosulfate: Performance and Inhomogeneous Activation Mechanism

2021 ◽  
Author(s):  
Rong Chen ◽  
Dan Zhao ◽  
Yanmao Dong ◽  
Chengrun Cai ◽  
Yan Yuan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Ph Value ◽  
Active Species ◽  
Ion Concentration ◽  
Activation Mechanism ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Initial Ph

Abstract manganese doped iron oxychloride (Mn-FeOCl) was synthesized by partial pyrolysis method. The Mn-FeOCl was used as heterogeneous catalyst to activate permonosulfate (PMS) for the degradation of azo dye acid red B(ARB) for the first time. The Mn-FeOCl was characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction spectroscopy (XRD). The effects of Mn-FeOCl dosage, PMS concentration, initial pH value, Cl ion concentration and humic acid (HA) dosage on the degradation of ARB by Mn-FeOCl/PMS were investigated. Results showed that the ARB was degraded effectively by Mn-FeOCl/PMS. The mineralization rate of ARB reached 42.5%. As the Mn-FeOCl dosage was 0.1g/L, PMS concentration was 1mmol/L, and ARB concentration was 0.05mmol/L, the degradation rate of ARB reached 99.4% in 30 minutes. With the increase of PMS dosage, Mn-FeOCl dosage, Cl− ion concentration and initial pH value, the decolorization effect of ARB increased. The reaction mechanism was analyzed by free radical quenching experiment and XPS. The main active species were determined as ·OH and SO4·− which generated by PMS activation. The SO4·−−was the main active species.

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.

scholarly journals Study of C.I. Acid Orange 7 removal in contaminated water by photo oxidation processes

2013 ◽  
Vol 10 (1) ◽  
pp. 16-23 ◽  
Keyword(s):  
Removal Efficiency ◽  
Uv Irradiation ◽  
Rate Constant ◽  
Dye Removal ◽  
Irradiation Time ◽  
Inhibitory Effect ◽  
Textile Dye ◽  
Acid Orange 7 ◽  
Acid Orange ◽  
First Order

C.I. Acid Orange 7 (AO7) commonly used as a textile dye and could be degraded by UV/ZnO, UV/H2O2 and UV/H2O2/Fe (III) (photofenton) processes. In the photocatalytic degradation of dye by UV/ZnO process, effect of some parameters such as UV irradiation time, presence of ZnO and UV irradiation, pH, concentrations of ZnO, dye, H2O2 and ethanol was examined and first order reaction rate constant was calculated equal to 2.39×10-2 min-1 at experimental condition. The semi-log plot of dye concentration versus time was linear, suggesting first order reaction. Efficiency of photodegradation process in the absence of ZnO photocatalyst and UV light was small. Increasing the UV irradiation time increased AO7 removal. Ethanol had inhibitory effect on this process. Maximum AO7 removal was seen at neutral pH area. In the UV/H2O2 process, effect of some parameters such as presence of H2O2 and UV irradiation, amount of H2O2, effect of pH and addition of bicarbonate on the efficiency of dye removal were examined. Absence of each of UV irradiation or H2O2 decreased AO7 removal efficiency near to zero. Increasing H2O2 concentration increased dye removal to some extent but at higher H2O2 concentrations, dye removal efficiency did not increase. Increasing pH to value about 9 increased the AO7 removal efficiency and increasing bicarbonate anion concentration decreased it. Rate constant of AO7 removal by this process was calculated to be equal to 4.221×10-1 min-1 at experimental condition. Also, the order of UV/ H2O2/Fe (III) > UV/ H2O2 > UV/Fe (III) > H2O2/Fe (III), was seen for AO7 removal efficiency of these processes. Increasing Fe (III) and oxalate concentration increased dye removal efficiency.

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