Decolorization and mineralization of diazo dye under artificial and solar light assisted Fenton and photo-Fenton conditions

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ibtissem Bousnoubra ◽  
Soumia Fassi ◽  
Kamel E. Djebbar
Keyword(s):  
Aqueous Solution ◽  
Reaction Time ◽  
Organic Carbon ◽  
Evans Blue ◽  
Oxygen Demand ◽  
Solar Light ◽  
Batch Experiments ◽  
Operational Conditions ◽  
Second Stage ◽  
Diazo Dye

Abstract The aim of this study is to verify the ability of some photochemical processes in the absence of light (Fenton) and in its presence (photolysis/UV, photo-Fenton/UV and photo-Fenton/Solar) to obtain total decolorization and mineralization of an diazo dye in aqueous solution: the Evans Blue (abbreviated as EB). Batch experiments were carried out to evaluate, on the first stage, the influence of different processes on EB decolorization and mineralization. During the second stage the optimal operational conditions like: H2O2 dosage, EB concentration and source of light were investigated. The reaction efficiencies have been compared for the same system in the dark or under the assistance of an artificial or solar light source. The obtained results showed that color removal followed the increasing order: photolysis/UV (18.2%) < Fe(II)/H2O2 (64.12%) < Fe(II)/H2O2/UV365 nm (83.4%) < Fe(II)/H2O2/solar light (86.3%) < Fe(II)/H2O2/UV254 nm (99.9%) with a reaction time of 60 min This improvement could be related to a better production of radicals OH•. In another hand, The efficiency of substrate mineralization in each process has been comparatively discussed by total organic carbon (TOC) and total chemical oxygen demand content of EB solutions.

Removal of diazo dye Direct Red 23 from aqueous solution using zero-valent iron nanoparticles immobilized on multi-walled carbon nanotubes

2015 ◽  
Vol 71 (9) ◽  
pp. 1367-1374 ◽  
Author(s):  
Mahmoud Reza Sohrabi ◽  
Nafiseh Mansouriieh ◽  
Morteza Khosravi ◽  
Mohsen Zolghadr
Keyword(s):  
Carbon Nanotubes ◽  
Aqueous Solution ◽  
Zero Valent Iron ◽  
Mass Ratio ◽  
Solution Ph ◽  
Operational Conditions ◽  
Multi Walled Carbon Nanotubes ◽  
Diazo Dye ◽  
Zero Valent Iron Nanoparticles ◽  
Walled Carbon Nanotubes

The present study immobilized nanoscale zero-valent iron (nZVI) on multi-walled carbon nanotubes (MWCNTs) to enhance the reactivity of nZVI and prevent its aggregation. This novel composite (nZVI/MWCNT) was characterized by scanning electron microscopy and X-ray diffraction. The results showed that nZVI particles dispersed on the surface of the MWCNTs. The composite was used to remove the diazo dye Direct Red 23 from aqueous solution. The effects of nZVI to MWCNT mass ratio, nanocomposite content, solution pH, initial dye concentration and temperature were studied. The optimum nZVI/MWCNT mass ratio was 1:3. Batch experiments suggest that degradation efficiency decreased as the initial dye concentration increased and increased as the nanocomposite content increased, decreasing the pH from 8 to 4. The reaction followed a pseudo-first-order model under the operational conditions investigated in this study.

scholarly journals Comparison between the photocatalytic degradation of single and binary azo dyes in TiO2 suspensions under solar light irradiation

2015 ◽  
Vol 5 (4) ◽  
pp. 579-591 ◽  
Author(s):  
Ohm-Mar Min ◽  
Li-Ngee Ho ◽  
Soon-An Ong ◽  
Yee-Shian Wong
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Photocatalytic Degradation ◽  
Azo Dyes ◽  
Azo Dye ◽  
Oxygen Demand ◽  
Light Irradiation ◽  
Solar Light ◽  
Acid Orange 7 ◽  
Solar Light Irradiation

Textile industries discharge a large quantity of colored wastewater which is harmful to the ecosystem. In this study, two kinds of dyes were investigated: the mono azo Acid Orange 7 (AO7) and diazo Reactive Green 19 (RG19). The photocatalytic degradation of single (AO7, RG19) azo dye and binary (AO7 and RG19 mixture) azo dye aqueous solutions was photocatalyzed by commercial titanium dioxide (TiO2, P25) under solar light irradiation. The objectives of this study are to compare the photocatalytic degradation between single and binary azo dye aqueous solution and to study the various parameters such as the effect of different initial azo dye concentrations, different initial azo dye pH values, and compare the adsorption capacity of azo dyes with and without solar light irradiation, which influences the photocatalytic activities of single and binary azo dye aqueous solutions in a TiO2 suspension. The results showed that photocatalytic degradation of AO7 and RG19 in a single azo dye aqueous solution was faster than a binary azo dye solution under the solar light irradiation process. Chemical oxygen demand results revealed that complete mineralization could be achieved for both AO7 and RG19 azo dyes under solar light irradiation within 22 hours.

Ibuprofen removal from aqueous solution by in situ electrochemically generated ferrate(VI): proof-of-principle

2015 ◽  
Vol 73 (2) ◽  
pp. 389-395 ◽  
Author(s):  
Ljiljana Nikolić-Bujanović ◽  
Milan Čekerevac ◽  
Milena Tomić ◽  
Mladen Zdravković
Keyword(s):  
Aqueous Solution ◽  
Organic Carbon ◽  
Aqueous Solutions ◽  
Phosphate Buffer ◽  
Phosphate Buffer Solution ◽  
Oxygen Demand ◽  
Buffer Solution ◽  
Effective Removal ◽  
Proof Of Principle

The possibility of removing pharmaceuticals from aqueous solutions was examined using ibuprofen (Ibu) oxidation as an example, using in situ electrochemically synthesized ferrate(VI), a strong oxidant and coagulant, with forming of non-harmful byproducts. A solution of ibuprofen of 206 mg/L in 0.1 M phosphate buffer solution was treated with different amounts of fresh, electrochemically synthesized ferrate(VI). The changes of ibuprofen concentration in samples were determined using a UV-Vis spectrophotometer. The extent of mineralization was estimated using the changes in chemical oxygen demand (COD) values and total organic carbon (TOC) values of test samples. The largest reduction of the concentration of Ibu (41.75%) was obtained by adding 69.2 mg/L ferrate(VI) as Fe (Ibu: Fe = 1: 0.34). An effective removal of ibuprofen from aqueous solutions was recorded up to 68% and it can be done by using ferrate(VI) in the ratio Ibu: Fe = 1:3 as Fe. The possibility of ibuprofen removal by ferrate(VI) was confirmed by COD and TOC results, which demonstrated reduction up to 65% and 63.6%, respectively.

Removal of Phosphate from Aqueous Solution by Using Red Mud

2011 ◽  
Vol 291-294 ◽  
pp. 1804-1807 ◽  
Author(s):  
Xin Feng Zhu ◽  
Hong Ye Liu ◽  
Peng Hui Shi ◽  
Jun Feng Wu ◽  
Yi Fei Guo
Keyword(s):  
Aqueous Solution ◽  
Reaction Time ◽  
Removal Efficiency ◽  
Red Mud ◽  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Batch Experiments ◽  
Reaction Conditions ◽  
Optimal Reaction

Red mud has been used to develop effective adsorbents to remove phosphate from aqueous solution. The effects of different dosage, pH of solution and reaction time on adsorption have been examined in batch experiments. It was found that red mud samples show higher removal efficiency for phosphate. The results showed that phosphate removal efficiency was found to be 97 % with optimal reaction conditions initial phosphate concentration 100mg L−1, red mud dosage 10g L−1, pH 2.0, respectively. The phosphate removal efficiency of the red mud adsorbents decreases with increase of pH.

Modeling and optimization of acid dye manufacturing wastewater treatment with Fenton's reagent: comparison with electrocoagulation treatment results and effects on activated sludge inhibition

2010 ◽  
Vol 62 (1) ◽  
pp. 209-216 ◽  
Author(s):  
Idil Arslan-Alaton ◽  
B. Hande Gursoy ◽  
Abdurahman Akyol ◽  
Mehmet Kobya ◽  
Mahmut Bayramoglu
Keyword(s):  
Reaction Time ◽  
Organic Carbon ◽  
Azo Dye ◽  
Polynomial Regression ◽  
Oxygen Demand ◽  
Inhibitory Effect ◽  
Interactive Effects ◽  
Treatment Results ◽  
Fenton’S Oxidation ◽  
Fenton's Oxidation

In the present study, Fenton's oxidation of a chromium complex disazo dye (Acid Blue 193) synthesis wastewater was evaluated, modeled and optimized by employing Central Composite Design. Within this context, the individual and interactive effects of critical process parameters such as Fe2 + , H2O2 concentrations, initial chemical oxygen demand (COD) and reaction time was assessed. The process response (output) variables were chosen as percent color, COD and total organic carbon (TOC) removal efficiencies. Optimum working conditions in terms of color and organic carbon removals were established to be Fe2 +  = 3 mM; H2O2 = 25 mM; reaction time = 10 min at pH 3 and an initial COD content of 245 mg/L. Under these conditions, 96% color, 82% COD and 51% TOC removals were obtained. The established polynomial regression models describing color, COD and TOC removals satisfactorily fitted the experimental data and could be used to predict Fenton's treatment results at statistically significant rates. Optimized treatment results were compared with those obtained via electrocoagulation treatment under optimized conditions (applied current = 50 A/m2; reaction time = 15 min; initial pH = 7 for an initial COD content of 245 mg/L). The relative inhibition of heterotrophic oxygen uptake rate was measured to examine the inhibitory effect of azo dye synthesis effluent before and after Fenton's oxidation and electrocoagulation with respect to synthetic domestic wastewater. Untreated azo dye production wastewater exhibited a slightly inhibitory effect that was appreciably reduced but not entirely removed after Fenton's oxidation, whereas no inhibition of mixed bioculture was observed for azo dye synthesis effluent subjected to electrocoagulation treatment.

Treatment of diazo dye C.I. Reactive Black 5 in aqueous solution by combined process of interior microelectrolysis and ozonation

2013 ◽  
Vol 67 (8) ◽  
pp. 1880-1885 ◽  
Author(s):  
Xiaoyan Guo ◽  
Yaping Cai ◽  
Zhongbo Wei ◽  
Haifeng Hou ◽  
Xi Yang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Oxygen Demand ◽  
Toxicity Tests ◽  
Reactive Black 5 ◽  
Optimal Conditions ◽  
Removal Rates ◽  
Combined Process ◽  
Toc Removal ◽  
Acute Toxicity Tests ◽  
Diazo Dye

Interior microelectrolysis (IM) as a pretreatment process was effective to treat Reactive Black 5 (RB5) in this study. The removal rates of chemical oxygen demand (COD), total organic carbon (TOC) and color were 46.05, 39.99 and 98.77%, respectively, when this process was conducted under the following optimal conditions: the volumetric ratio between iron scraps and active carbon (AC) (V(Fe)/V(C)) 1.0, pH 2.0, aeration dosage 0.6 L/min, and reaction time 100 min. Contaminants could be further removed by ozonation. After subsequent ozonation for 200 min, the solution could be completely decolorized, and the COD and TOC removal rates were up to 77.78 and 66.51%, respectively. In addition, acute toxicity tests with Daphnia magna showed that pretreatment by IM generated effluents that were more toxic when compared with the initial wastewater, and the toxicity was reduced after subsequent ozonation.

scholarly journals The correlation analysis of TOC, CODCr and fluorescence characteristics in MPR

2020 ◽  
Vol 194 ◽  
pp. 04014
Author(s):  
Xi Tian ◽  
Ying Liu ◽  
Chunling Zhao ◽  
Xiaona Ji ◽  
Zhiming Ren ◽  
...  
Keyword(s):  
Reaction Time ◽  
Organic Carbon ◽  
Treatment Time ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Biochemical Treatment ◽  
Excitation Emission Matrix ◽  
Fluorescence Characteristics ◽  
Degradation Effect ◽  
Eem Fluorescence

Water samples from different biochemical reaction time in one reactor period in Micro-Pressure Inner-Loop Bioreactor (MPR) were measured respectively with adopt Excitation-emission matrix (EEM) fluorescence spectroscopy, Total organic carbon (TOC) and chemical oxygen demand (CODCr),analyzed the correlation among the fluorescence integrates volume, TOC and CODCr.Results showed that with the increase of biochemical treatment time, sewage fluorescence integrates volume declined significantly, known fluorescence integrates volume, CODCr and TOC value better correlation, by fluorescence spectrometry analyzed fluorescence characteristics of sewage to determine the organic wastewater degradation effect, can be simpler and more rapid the judgment of the sewage treatment effect.

Evaluating photo-degradation of COD and TOC in petroleum refinery wastewater by using TiO2/ZnO photo-catalyst

2016 ◽  
Vol 74 (6) ◽  
pp. 1312-1325 ◽  
Author(s):  
Dheeaa al deen Atallah Aljuboury ◽  
Puganeshwary Palaniandy ◽  
Hamidi Bin Abdul Aziz ◽  
Shaik Feroz ◽  
Salem S. Abu Amr
Keyword(s):  
Reaction Time ◽  
Treatment Time ◽  
Removal Rate ◽  
Air Flow ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Removal Rates ◽  
Operational Conditions ◽  
Photo Catalyst

The aim of this study is to investigate the performance of combined solar photo-catalyst of titanium oxide/zinc oxide (TiO2/ZnO) with aeration processes to treat petroleum wastewater. Central composite design with response surface methodology was used to evaluate the relationships between operating variables for TiO2 dosage, ZnO dosage, air flow, pH, and reaction time to identify the optimum operating conditions. Quadratic models for chemical oxygen demand (COD) and total organic carbon (TOC) removals prove to be significant with low probabilities (&lt;0.0001). The obtained optimum conditions included a reaction time of 170 min, TiO2 dosage (0.5 g/L), ZnO dosage (0.54 g/L), air flow (4.3 L/min), and pH 6.8 COD and TOC removal rates of 99% and 74%, respectively. The TOC and COD removal rates correspond well with the predicted models. The maximum removal rate for TOC and COD was 99.3% and 76%, respectively at optimum operational conditions of TiO2 dosage (0.5 g/L), ZnO dosage (0.54 g/L), air flow (4.3 L/min), reaction time (170 min) and pH (6.8). The new treatment process achieved higher degradation efficiencies for TOC and COD and reduced the treatment time comparing with other related processes.

Hydro-geochemical properties with respect to landuse in the southernmost river of Kerala

2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Badusha M. ◽  
Santhosh S
Keyword(s):  
Organic Carbon ◽  
Drainage Basin ◽  
Anthropogenic Activities ◽  
Oxygen Demand ◽  
Ion Concentration ◽  
Total Hardness ◽  
Hydrogen Ion Concentration ◽  
Geochemical Properties ◽  
Quality Of Water

The hydro geochemical features of Neyyar River for a period of one year from May 2015 to April 2016 were analyzed. Six sampling sites were fixed considering physiography and present landuse pattern of the river basin. The residents in the drainage basin are primarily responsible for framing a better landuse and thereby maintain a good water and sediment regime. Geospatial pattern of the present landuse of the study area indicated that the sustainability of this river ecosystem is in danger due to unscientific landuse practices, which is reflected in the river quality as well. The parameters such as hydrogen ion concentration, electrical conductivity, chloride, Biological Oxygen Demand, total hardness and sulphate of river water and Organic Carbon of river bed sediments were analyzed in this study. The overall analysis shows that the highland areas are characterized by better quality of water together with low organic carbon, which is mainly due to better landuse and minimal reclamation. The midland and lowland areas are characterized by poor quality of water with high organic carbon, which is due to high anthropogenic activities and maximum pollutants associated with the region together with the alteration in landuse from a traditional eco-friendly pattern to a severely polluted current pattern.

Anaerobic/aerobic biodegradation of pentachlorophenol using GAC fluidized bed reactors: optimization of the empty bed contact time

1997 ◽  
Vol 36 (6-7) ◽  
pp. 107-115 ◽  
Author(s):  
Gregory J. Wilson ◽  
Amid P. Khodadoust ◽  
Makram T. Suidan ◽  
Richard C. Brenner
Keyword(s):  
Fluidized Bed ◽  
Oxygen Demand ◽  
Aerobic Biodegradation ◽  
Fluidized Bed Reactors ◽  
Reactor Performance ◽  
Reactor Operation ◽  
Significant Cost ◽  
Second Stage ◽  
Primary Substrate ◽  
Chlorinated Phenolic Compounds

An integrated reactor system has been developed to remediate pentachlorophenol (PCP) containing wastes using sequential anaerobic and aerobic biodegradation. Anaerobically, PCP was degraded to predominately equimolar concentrations (&gt;99%) of monochlorophenol (MCP) in two GAC fluidized bed reactors at Empty Bed Contact Times (EBCTs) ranging from 18.6 to 1.15 hours. However, at lower EBCTs, MCP concentrations decreased to less than 10% of the influent PCP concentration suggesting mineralization. The optimal EBCT was determined to be 2.3 hours based on PCP conversion to MCPs and stable reactor operation. Decreasing the EBCT fourfold did not inhibit degradation of PCP and its intermediates, thus allowing removal of PCP at much lower detention time and resulting in a significant cost advantage. Analytical grade PCP was fed via syringe pumps into two fluidized bed reactors at influent concentrations of 100 mg/l and 200 mg/l, respectively. Acting as the primary substrate, ethanol was also fed into the reactors at concentrations of 697 and 1388 mg/l. Effluent PCP and chlorinated phenolic compounds were analyzed weekly to evaluate reactor performance. Biodegradation pathways were also identified. 3-chlorophenol (CP) was the predominant MCP and varied simultaneously with 3,5-dichlorophenol (DCP) concentrations. Likewise, 4-CP concentrations varied simultaneously with 3,4-DCP concentrations. A second stage aerobic GAC fluidized bed reactor was added after the anaerobic reactor to completely mineralize the remaining MCP and phenols. Data show no presence of phenol and MCP in the effluent or on the GAC. Overall, the chemical oxygen demand (COD) fed to the system was reduced from 75 g/d in the influent to less than 1.5 g/d in the effluent.

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