Photocatalytic Degradation of Diisopropanolamine in Heterogeneous Photo-Fenton System

2014 ◽  
Vol 917 ◽  
pp. 160-167 ◽  
Author(s):  
Raihan Mahirah Ramli ◽  
Chong Fai Kait ◽  
Abdul Aziz Omar
Keyword(s):  
Visible Light ◽  
Photocatalytic Degradation ◽  
Removal Efficiency ◽  
Cod Removal ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
Similar Activity ◽  
Cod Removal Efficiency ◽  
Wet Impregnation Method ◽  
Fenton System

Photodegradation of 100 ppm diisopropanolamine (DIPA) was studied employing heterogeneous photo-Fenton system using iron modified TiO2 photocatalyst. A series of Fe/TiO2 photocatalysts were prepared via hydrolysis-hydrothermal and wet impregnation methods. Photocatalysts prepared using wet impregnation method was found to have similar activity under both UV and visible light. Addition of H2O2 during the photodegradation study obviously promoted the COD removal efficiency. When stoichiometric concentration of H2O2 was added, as high as 80% of COD was removed within 1.5 h reaction. Further modification is required to increase the photocatalyst performance in photodegradation of DIPA.

Visible light-driven enhanced CO2 reduction by water over Cu modified S-doped g-C3N4

2019 ◽  
Vol 9 (17) ◽  
pp. 4598-4613 ◽  
Author(s):  
Niwesh Ojha ◽  
Abhinav Bajpai ◽  
Sushant Kumar
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Co2 Reduction ◽  
Impregnation Method ◽  
Thin Sheets ◽  
Wet Impregnation ◽  
Visible Light Driven ◽  
Plausible Mechanism ◽  
Wet Impregnation Method

We synthesized Cu modified S-doped g-C3N4 thin sheets using calcination followed by a wet-impregnation method. The photocatalytic activity was studied for reduction of CO2 to CO and CH4 in the presence of water and a plausible mechanism is explained.

scholarly journals Mesoporous Ce-doped Ti:Ash Photocatalyst Investigation in Visible Light Photocatalytic Water Pretreatment Process

2020 ◽  
Vol 15 (2) ◽  
pp. 367-378
Author(s):  
Abdulkarim Abdulrahman Mohamed Suliman ◽  
Ruzinah Isha ◽  
Mazrul Nizam Abu Seman ◽  
Abdul Latif Ahmad ◽  
Jamil Roslan
Keyword(s):  
Visible Light ◽  
Visible Region ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
X Ray ◽  
Weight Percentage ◽  
Water Pretreatment ◽  
Defect Sites ◽  
Adsorption Desorption ◽  
Wet Impregnation Method

The treatment of organic pollutants in water including semiconductor photocatalysis is a promising approach to disinfect water. The objective of this study is to investigate the effect of Ce loaded on mesoporous Ti:Ash catalyst for water pretreatment process. The mesoporous Ti:Ash catalyst that doped with Ce was synthesized through wet impregnation method with 5%, 10%, and 15% weight percentage of Ce doped on 40:60 Ti:Ash. The photocatalytic properties were characterized through X-ray powder diffraction, scanning electron microscopy with energy-dispersive X-ray spectroscopy, N2 adsorption-desorption studies and diffuse reflectance UV–vis absorption spectroscopy. It is found that the Ti:Ash nanocomposites doped with Ce shifted the light absorption band-edge position to the visible region. Moreover, the Ce doped Ti:Ash has large surface area and pore diameter. The Ce doping could significantly improve the absorption edge of visible light and adjust the cut-off absorption wavelength from 404 nm to 451, 477 and 496 nm for 5%, 10% and 15% Ce-doped mesoporous Ti:Ash catalysts, respectively. As the Ce doping ratio increased, the band gaps decreased from 3.06 eV to 2.53 eV. The most contaminant reduction up to 45% was achieved when Ti:Ash:Ce 40:55:5 was used. Higher Ce loading on the photocatalyst may reduce the photocatalyst performance because supernumerary metal loading on TiO2 can block TiO2 defect sites which are necessary for the adsorption and photoactivation. The OPFA also acts as an adsorbent for some pollutants besides, reducing the water salinity. It can be deduced that the hybrid TiO2 photocatalyst that synthesized with OPFA and doped with Ce has huge potential to treat seawater prior to commercial seawater desalination process. Copyright © 2020 BCREC Group. All rights reserved 

scholarly journals Photocatalytic degradation of the 2,4-dichlorophenoxyacetic acid herbicide using supported iridium materials

2021 ◽  
Vol 12 (1) ◽  
pp. 125-134
Author(s):  
Claudia Patricia Castañeda Martínez ◽  
Ignacio Alfonso Alvarado Ortega ◽  
Hugo Alfonso Rojas Sarmiento ◽  
Francisco Javier Tzompantzi Morales ◽  
José Ricardo Gómez Romero
Keyword(s):  
Photocatalytic Degradation ◽  
Band Gap Energy ◽  
Charge Carriers ◽  
Dichlorophenoxyacetic Acid ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
Improved Performance ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Wet Impregnation Method

In this work, the effect of the addition of iridium on TiO2 and Nb2O5 supports obtained by wet impregnation method was evaluated in the photocatalytic degradation of 2,4-dichlorophenoxiacetic acid under UV irradiation. The synthetized materials were analyzed by different techniques in order to determinate their physicochemical properties. In general, it was observed that the addition of iridium modifies the surface area, band gap energy and it enhances the crystallinity of the materials. Besides, an increase in the photoactivity in the degradation of the herbicide was evidenced using the materials modified. However, the Ir/TiO2 photocatalyst possess the best photocatalytic behavior toward the degradation and possible mineralization of the herbicide. The improved performance of the photocatalyst could be argued by the role of the iridium particles as electron collectors favoring the effective separation of the charge carriers and, as consequence, increasing the degradation of the molecule.           

scholarly journals Improved removal performance and mechanism investigation of papermaking wastewater treatment using manganese enhanced Fenton reaction

2018 ◽  
Vol 77 (10) ◽  
pp. 2509-2516 ◽  
Author(s):  
Yingcai Wang ◽  
Can Wang ◽  
Shuai Shi ◽  
Shuai Fang
Keyword(s):  
Removal Efficiency ◽  
Fenton Reaction ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Pseudo First Order Reaction ◽  
Kinetic Rate Constant ◽  
Practical Applications ◽  
Cod Removal Efficiency ◽  
Fenton System ◽  
Papermaking Wastewater

Abstract The effects of Mn(II) on Fenton system to treat papermaking wastewater and the mechanism of Mn(II) enhanced Fenton reaction were investigated in this study. The chemical oxygen demand (COD) removal efficiency was enhanced in the presence of Mn(II), which increased by 19% compared with that of the Fenton system alone. The pseudo-first order reaction kinetic rate constant of Mn(II)/Fenton system was 2.11 times higher than that of Fenton system. 67%–81% COD were removed with the increasing Mn(II) concentration from 0 to 0.8 g/L. COD removal efficiency was also enhanced in a wider pH range (3–7), which indicated the operation parameters of Fenton technology could be broadened to a milder condition. The study of the mechanism showed that Mn(II) participated in the oxidation and coagulation stages in Fenton system. In the oxidation stage, Mn(II) promotes the production of HO2•/ O2•−, then HO2•/ O2•− reacts with Fe(III) to accelerate the formation of Fe(II), and finally accelerates the production of HO•. Meantime MnMnO3 and Fe(OH)3 forms in the coagulation stage, facilitating the removal of suspended substances and a large amount of COD, which enhances the overall COD removal of papermaking wastewater. This study provided a detailed mechanism to improve practical applications of Fenton technology.

scholarly journals Investigation of Heavy Metal Effects on the Anaerobic Co-Digestion Process of Waste Activated Sludge and Septic Tank Sludge

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Quang-Minh Nguyen ◽  
Duy-Cam Bui ◽  
Thao Phuong ◽  
Van-Huong Doan ◽  
Thi-Nham Nguyen ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Biogas Production ◽  
Cod Removal ◽  
Septic Tank ◽  
Waste Activated Sludge ◽  
Digestion Process ◽  
Cod Removal Efficiency

The effect of copper, zinc, chromium, and lead on the anaerobic co-digestion of waste activated sludge and septic tank sludge in Hanoi was studied in the fermentation tests by investigating the substrate degradation, biogas production, and process stability at the mesophilic fermentation. The tested heavy metals were in a range of concentrations between 19 and 80 ppm. After the anaerobic tests, the TS, VS, and COD removal efficiency was 4.12%, 9.01%, and 23.78% for the Cu(II) added sample. Similarly, the efficiencies of the Zn(II) sample were 1.71%, 13.87%, and 16.1% and Cr(VI) efficiencies were 15.28%, 6.6%, and 18.65%, while the TS, VS, and COD removal efficiency of the Pb(II) added sample was recorded at 16.1%, 17.66%, and 16.03% at the concentration of 80 ppm, respectively. Therefore, the biogas yield also decreased by 36.33%, 31.64%, 31.64%, and 30.60% for Cu(II), Zn(II), Cr(VI), and Pb(II) at the concentration of 80 ppm, compared to the raw sample, respectively. These results indicated that Cu(II) had more inhibiting effect on the anaerobic digestion of the sludge mixture than Zn(II), Cr(VI), and Pb(II). The relative toxicity of these heavy metals to the co-digestion process was as follows: Cu (the most toxic) > Zn > Cr > Pb (the least toxic). The anaerobic co-digestion process was inhibited at high heavy metal concentration, which resulted in decreased removal of organic substances and produced biogas.

scholarly journals Combined treatment of hydroxypropyl guar gum in oilfield fracturing wastewater by coagulation and the UV/H2O2/ferrioxalate complexes process

2017 ◽  
Vol 77 (3) ◽  
pp. 565-575 ◽  
Author(s):  
Zhenchao Zhang
Keyword(s):  
Removal Efficiency ◽  
Guar Gum ◽  
Combined Treatment ◽  
Cod Removal ◽  
Treated Wastewater ◽  
Spectra Analysis ◽  
Hydroxypropyl Guar ◽  
Coagulation Process ◽  
Cod Removal Efficiency ◽  
Hydroxypropyl Guar Gum

Abstract Hydroxypropyl guar gum is considered to be a main component of oilfield fracturing wastewater (OFW). This work is intended to optimize the experimental conditions for the maximum oxidative degradation of hydroxypropyl guar gum by the coagulation and UV/H2O2/ferrioxalate complexes process. Optimal reaction conditions were proposed based on the chemical oxygen demand (COD) removal efficiency and UV_vis spectra analysis. The overall removal efficiency of COD reached 83.8% for a dilution ratio of raw wastewater of 1:2, pH of 4 and FeCl3 loading of 1,000 mg/L in the coagulation process; the dosage of H2O2 (30%,v/v) was 0.6% (v/v) and added in three steps, the n(H2O2)/n(Fe2+) was 2:1, n(Fe2+)/n(C2O42−) was 3:1 and pH was 4 in the UV/H2O2/ferrioxalate complexes process; pH was adjusted to 8.5–9 by NaOH and then cationic polyacrylamide (CPAM) of 2 mg/L was added in the neutralization and flocculation process. The decrease in COD during the coagulation process reduced the required H2O2 dosage and improved efficiency in the subsequent UV/H2O2/ferrioxalate complexes process. Furthermore, COD removal efficiency significantly increased by more than 13.4% with the introduction of oxalate compared with UV/Fenton. The UV_vis spectra analysis results indicated that the coagulation and UV/H2O2/ferrioxalate complexes process could efficiently remove the hydroxypropyl guar gum dissolved in OFW. An optimal combination of these parameters produced treated wastewater that met the GB8978-1996 Integrated Wastewater Discharge Standard level III emission standard.

Textile Wastewater Treatment Using Combined Process of Biological Wriggle Bed and Ozone Biological Aerated Filter

2012 ◽  
Vol 441 ◽  
pp. 589-592
Author(s):  
Zhi Min Fu ◽  
Yu Gao Zhang ◽  
Xiao Jun Wang
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Textile Wastewater ◽  
Cod Removal ◽  
Biological Aerated Filter ◽  
Combined Process ◽  
Cod Removal Efficiency ◽  
Aerated Filter ◽  
Textile Wastewater Treatment

A combined process of biological wriggle bed and ozone biological aerated filter was utilized to treat textile wastewater. Results showed that COD removal efficiency was almost 90.4%. The average effluent COD was 85.87 mg/L. The effluent colority was 64-32 times. This study indicated that the combined process is potentially useful for treating textile wastewater.

Electrocoagulation and nanofiltration integrated process application in purification of bilge water using response surface methodology

2016 ◽  
Vol 74 (3) ◽  
pp. 564-579 ◽  
Author(s):  
Ceyhun Akarsu ◽  
Yasin Ozay ◽  
Nadir Dizge ◽  
H. Elif Gulsen ◽  
Hasan Ates ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Removal Efficiency ◽  
Cod Removal ◽  
Positive Sign ◽  
Aluminum Electrode ◽  
Integrated Process ◽  
Bilge Water ◽  
Cod Removal Efficiency ◽  
Initial Ph

Marine pollution has been considered an increasing problem because of the increase in sea transportation day by day. Therefore, a large volume of bilge water which contains petroleum, oil and hydrocarbons in high concentrations is generated from all types of ships. In this study, treatment of bilge water by electrocoagulation/electroflotation and nanofiltration integrated process is investigated as a function of voltage, time, and initial pH with aluminum electrode as both anode and cathode. Moreover, a commercial NF270 flat-sheet membrane was also used for further purification. Box–Behnken design combined with response surface methodology was used to study the response pattern and determine the optimum conditions for maximum chemical oxygen demand (COD) removal and minimum metal ion contents of bilge water. Three independent variables, namely voltage (5–15 V), initial pH (4.5–8.0) and time (30–90 min) were transformed to coded values. The COD removal percent, UV absorbance at 254 nm, pH value (after treatment), and concentration of metal ions (Ti, As, Cu, Cr, Zn, Sr, Mo) were obtained as responses. Analysis of variance results showed that all the models were significant except for Zn (P > 0.05), because the calculated F values for these models were less than the critical F value for the considered probability (P = 0.05). The obtained R2 and Radj2 values signified the correlation between the experimental data and predicted responses: except for the model of Zn concentration after treatment, the high R2 values showed the goodness of fit of the model. While the increase in the applied voltage showed negative effects, the increases in time and pH showed a positive effect on COD removal efficiency; also the most effective linear term was found as time. A positive sign of the interactive coefficients of the voltage–time and pH–time systems indicated synergistic effect on COD removal efficiency, whereas interaction between voltage and pH showed an antagonistic effect.

scholarly journals Impact of Precipitants on the Structure and Properties of Fe-Co-Ce Composite Catalysts

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Yongli Zhang ◽  
Shujuan Dai ◽  
Yanbo Zhou ◽  
Kai Lin
Keyword(s):  
Particle Size ◽  
Methyl Orange ◽  
Removal Efficiency ◽  
Cod Removal ◽  
Catalytic Wet Air Oxidation ◽  
Structure And Properties ◽  
Air Oxidation ◽  
Wet Air Oxidation ◽  
Composite Catalysts ◽  
Cod Removal Efficiency

Fe-Co-Ce composite catalysts were prepared by coprecipitation method using CO(NH2)2, NaOH, NH4HCO3, and NH3·H2O as precipitant agents. The effects of the precipitant agents on the physicochemical properties of the Fe-Co-Ce based catalysts were investigated by SEM, TEM, BET, TG-DTA, and XRD. It was found that the precipitant agents remarkably influenced the morphology and particle size of the catalysts and affected the COD removal efficiency, decolorization rate, and pH of methyl orange for catalytic wet air oxidation (CWAO). The specific surface area of the Fe-Co-Ce composite catalysts successively decreased in the order of NH3·H2O, NH4HCO3, NaOH, and CO(NH2)2, which correlated to an increasing particle size that increased for each catalyst. For the CWAO of a methyl orange aqueous solutions, the effects of precipitant agents NH3·H2O and NaOH were superior to those of CO(NH2)2and NH4HCO3. The catalyst prepared using NH3·H2O as the precipitant agent was mostly composed of Fe2O3, CoO, and CeO2. The COD removal efficiency of methyl orange aqueous solution for NH3·H2O reached 92.9% in the catalytic wet air oxidation. Such a catalytic property was maintained for six runs.

Development of a two-stage flexible fibre biofilm reactor for treatment of food processing wastewater

2003 ◽  
Vol 47 (11) ◽  
pp. 189-194 ◽  
Author(s):  
Q.J. Yu ◽  
H. Xu ◽  
D. Yao ◽  
P. Williams
Keyword(s):  
Removal Efficiency ◽  
Food Processing ◽  
Cost Effective ◽  
Biofilm Reactor ◽  
Cod Removal ◽  
Two Stage ◽  
Cod Removal Efficiency ◽  
Cost Effective Treatment ◽  
Removal Efficiencies ◽  
Food Processing Wastewater

Biofilm (or attached growth) reactors can be effectively used to treat organic wastewater from various industries such as food processing industry. They have a number of advantages including high organic loading rates (OLRs) and improved operational stability. A flexible fibre biofim reactor (FFBR) has been developed for efficient and cost effective treatment of food processing wastewater. In the process, simple flexible fibre packing with a very high specific surface area is used as support for microorganisms. The COD removal efficiencies for a range of OLRs have been studied. The FFBR can support an increasingly high OLR, but with a corresponding decrease in the COD removal efficiency. Therefore, a two-stage FFBR was developed to increase the treatment efficiency for systems with high OLRs. Experimental results indicated that a high overall COD removal efficiency could be achieved. At an influent COD of about 2700 mg/L and an OLR of 7.7 kgCOD/m3d, COD removal efficiencies of 76% and 82% were achieved in the first and the second stage of the reactor, respectively. The overall COD removal efficiency was 96%. Therefore, even for wastewater samples with high organic strength, high quality treated effluents could be readily achieved by the use of multiple stage FFBRs.

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