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.

Decolorization of azo dye C.I. Reactive Black 5 by ozonation in aqueous solution: influencing factors, degradation products, reaction pathway and toxicity assessment

2015 ◽  
Vol 73 (7) ◽  
pp. 1500-1510 ◽  
Author(s):  
Qing Zheng ◽  
Yong Dai ◽  
Xiangyun Han
Keyword(s):  
Aqueous Solution ◽  
Degradation Products ◽  
Reaction Pathway ◽  
Degradation Mechanism ◽  
Exchange Chromatography ◽  
Computational Method ◽  
Photobacterium Phosphoreum ◽  
Toxicity Tests ◽  
Reactive Black 5 ◽  
Oh Groups

In this study, ozonation treatment of C.I. Reactive Black 5 (RB5) was investigated at various operating parameters. The results showed that the aqueous solution initially containing 200 mg/L RB5 was quickly decolorized at pH 8.0 with an ozone dose of 3.2 g/h. Reaction intermediates with m/z 281, 546, 201, 350, 286 and 222 were elucidated using liquid chromatography-mass spectrometry, while sulfate ion, nitrate ion and three carboxylic acids (i.e., oxalic acid, formic acid, and acetic acid) were identified by ion exchange chromatography. Thus, the cleavage of the azo bond and the introduction of OH groups in the corresponding positions were proposed as the predominant reaction pathway. The detachment of sulfonic groups was also commonly observed during the ozonation treatment. The proposed degradation mechanism was confirmed by frontier electron density calculations, suggesting the feasibility of predicting the major events in the whole ozonation process with the computational method. Compared with RB5 degradation, the reduction of total organic carbon (TOC) proceeded much more slowly, and approximately 54% TOC was removed after 4 h of ozonation. Acute toxicity tests with Photobacterium phosphoreum showed that the toxicity of reaction solution was firstly increased and then decreased to a negligible level after 160 min.

scholarly journals Treatment of Landfill Leachates with Combined Acidification/Coagulation and The Fe0/H2O2 Process

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 194 ◽  
Author(s):  
Jan Bogacki ◽  
Piotr Marcinowski ◽  
Balkess El-Khozondar
Keyword(s):  
Statistical Analysis ◽  
Processing Time ◽  
Oxygen Demand ◽  
Treatment Method ◽  
Environmental Concerns ◽  
Landfill Leachates ◽  
Complex Composition ◽  
Combined Process ◽  
Initial Concentration ◽  
Toc Removal

One of the major environmental concerns associated with waste disposal is the large amount of generated landfill leachates (LL), which are considered a type of wastewater with a complex composition. There is an urgent need to find an effective LL treatment method. LL were subjected to pretreatment followed by the Fe0/H2O2 process. Pretreatment efficiency was coagulation at pH 6.0 >> coagulation at pH 9.0 > acidification at pH 3.0. Coagulation at pH 6.0 in an optimal Fe3+ dose of 1000 mg/L decreased total organic carbon (TOC) from the initial concentration of 1061 mg/L to 491 mg/L while acidification to pH 3.0 decreased TOC to 824 mg/L. After acidification, the Fe0/H2O2 process with 8000/9200 mg/L Fe0/H2O2 reagent doses decreased TOC to 499 mg/L after a processing time of 60 min. Performance of the Fe0/H2O2 process after coagulation at pH 6.0 for optimal Fe0/H2O2 8000/5540 mg/L reagent doses decreased TOC to 268 mg/L (75% TOC removal). Treatment of landfill leachates with combined process coagulation and Fe0/H2O2 also increased their susceptibility to biodegradation, expressed as the biochemical oxygen demand/chemical oxygen demand (BOD5/COD) ratio from 0.13 to 0.43, allowing LL to be considered as susceptible to biodegradation. Fe0/H2O2 process kinetics was described. A statistical analysis confirmed the obtained results. The proposed method can be successfully applied for LL treatment.

Productive Experiment of Combined Process Treating Sewage of Three Gorges Reservoir Region

2011 ◽  
Vol 90-93 ◽  
pp. 2444-2450
Author(s):  
Xiao Xia Ma ◽  
Lei Huang ◽  
Jing Song Guo
Keyword(s):  
Three Gorges Reservoir ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Domestic Sewage ◽  
Three Gorges ◽  
Removal Rates ◽  
Combined Process ◽  
Effluent Concentration ◽  
Three Gorges Reservoir Region ◽  
The Impact

To investigate the domestic sewage treatment processes fitting for small mountain towns in Three Gorges Reservoir Region, a demonstration project was built to treat domestic sewage which combined with anaerobic hydrolysis, natural water-dropping aeration and improved artificial soil rapid infiltration and was based on the features of large terrain elevation and many barren ravines. Changes of major pollutants were analyzed in the combined process. The impact of temperature and influent loadings on removal rates of pollutants was investigated. The results showed that, the treatment system had a strong resistance to the influent loadings with good removal rates of pollutants. There was a relationship between temperature and the removal rates of chemical oxygen demand, ammonia and total nitrogen in the system, where the removal rate of total phosphorus was not associated with temperature. There was a clear linear relationship between effluent concentration and influent loadings, effluent concentration increased with influent loadings. There were approximate logarithmic relationships between removal loadings per unit area and influent loadings.

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.

scholarly journals Photo-Fenton Degradation of RB5 Dye in Aqueous Solution Using Fe Supported on Mexican Natural Zeolite

2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
José Domenzain-Gonzalez ◽  
José J. Castro-Arellano ◽  
Luis A. Galicia-Luna ◽  
Luis Lartundo-Rojas
Keyword(s):  
Aqueous Solution ◽  
Chemical Oxygen Demand ◽  
Natural Zeolite ◽  
Oxygen Demand ◽  
Main Element ◽  
Natural Material ◽  
Reactive Black 5 ◽  
Chemical Oxygen Demand Removal ◽  
X Ray ◽  
Vis Spectroscopy

A Mexican natural zeolite (MNZ) was impregnated with Fe at concentrations of 5 and 10 mg FeCl3/g MNZ (MNZ/Fe) in order to study the photo-Fenton degradation of Reactive Black 5 (RB5) dye. Two samples were prepared and calcined at 550 and 700°C for each concentration. These samples were also characterized by the following techniques: X-ray diffraction (XRD) to determine crystalline phases of mineral, X-ray photoelectron spectroscopy (XPS) to observe the elemental composition of the material where the main element was Fe as Fe2p, Mössbauer to establish the phases in the material which were magnetite (Fe3O4), fayalite, and chlorite, Raman to corroborate that magnetite clusters in natural material were presented, and transmission electron microscopy (TEM) by which magnetite nanoparticles were observe on zeolite surface. Afterwards, the catalytic degradation of RB5 dye was performed by photo-Fenton process using a 2.2 W lamp as a radiation source. Four initial concentrations of RB5 dye ((RB5)0) were evaluated which ranged from 40 to 100 mg/L. Then, the evaluation reaction was carried out by UV-Vis spectroscopy to know the change in RB5 concentration and chemical oxygen demand (COD) removal to determine the organic carbon. The best results on the photo-Fenton degradation was 91% discoloration and 68.5% chemical oxygen demand removal based on an initial concentration RB50=100 mg/L and 10 mg MNZ/Fe (700°C of calcined temperature) at MNZ/Fe=0.05 g/L catalyst dose in aqueous solution, H2O2=3 g/L, pH=2.5, and 180 minutes of reaction time. Subsequently, variations on (RB5)0, pH, (H2O2), and (MNZ/Fe) were assessed in order to optimize the process by keeping 10 MNZ/Fe. The optimal RB5 dye degradation was achieved at RB50=100 mg/L in the presence of MNZ/Fe=0.2 g/L, H2O2=3 g/L and pH=2.5 where the highest discoloration and chemical oxygen demand removal were 93 and 70.5 at 180 min. Finally, the kinetic reaction was evaluated as a pseudo-first-order kinetics with an apparent rate constant (kapp) of 0.0225 min-1 at latest conditions.

Integration of US/Fe2+ and photo-Fenton in sequencing for degradation of landfill leachate

2015 ◽  
Vol 73 (2) ◽  
pp. 260-266 ◽  
Author(s):  
F. G. Zha ◽  
D. X. Yao ◽  
Y. B. Hu ◽  
L. M. Gao ◽  
X. M. Wang
Keyword(s):  
Removal Efficiency ◽  
Landfill Leachate ◽  
Oxygen Demand ◽  
Gas Chromatography Mass Spectrometry ◽  
Fenton Process ◽  
Optimal Conditions ◽  
Initial Concentration ◽  
Toc Removal ◽  
The Us ◽  
Initial Ph

The landfill leachate treated by sonication in presence of Fe2+ (US/Fe2+) and then by photo-Fenton achieved the highest total organic carbon (TOC) removal efficiency among the screened processes. The lower initial pH, dosage of Fe2+ and initial concentration of leachate were helpful in raising TOC removal efficiency of leachate by US/Fe2+. The optimal conditions for the US-photo-Fenton process were as follows: initial pH at 3.0, [H2O2]/[TOC0] at 2, [H2O2]/[Fe2+] at 5 and initial concentration of landfill leachate at 600 mg/L. The removal efficiency of TOC, chemical oxygen demand (COD) and 5-day biochemical oxygen demand (BOD5) were 68.3, 79.6 and 58.2%, while the BOD5/COD rose from 0.20 to 0.43 at optimum condition. Based on gas chromatography–mass spectrometry (GC-MS) results, 36 of a total of 56 pollutants were completely degraded by US-photo-Fenton treatment.

Comparison of the sensitivities of fish, Microtox and Daphnia-magna bioassays to amoxycillin in anaerobic/aerobic sequential reactor systems

2012 ◽  
Vol 66 (5) ◽  
pp. 1117-1131 ◽  
Author(s):  
H. Çelebi ◽  
D. T. Sponza
Keyword(s):  
Acute Toxicity ◽  
Daphnia Magna ◽  
Vibrio Fischeri ◽  
Oxygen Demand ◽  
Toxicity Tests ◽  
Resistant Organism ◽  
Acute Toxicity Tests ◽  
Methane Production Rate ◽  
Continuously Stirred Tank Reactor ◽  
Cstr System

In this study the anaerobic treatability of amoxycillin (AMX) was investigated in a laboratory-scale anaerobic multi-chamber bed reactor (AMCBR)/aerobic continuously stirred tank reactor (CSTR) system. The chemical oxygen demand (COD) and AMX removal efficiencies were around 94% in the AMCBR reactor at hydraulic retention times (HRTs) between 2.25 and 5.5 days. Decreasing the HRT appeared not to have a significant effect on the performance of the AMCBR up to a HRT of 1.13 days. The maximum methane production rate and methane percentage were around 1,100–1,200 mL/day and 55%, respectively, at HRTs between 2.25 and 5.5 days. The decrease in HRT to 1.5 days decreased slightly the gas productions (1,000 mL/day and 500 mL for total and methane gases) and methane percentage (45%). The AMCBR recovered back to its baseline performance within a couple of days. The acute toxicity of 150 mg/L AMX was monitored with Daphnia magna, Lepistes sp., and Vibrio fischeri acute toxicity tests. The acute toxicity removals were 98, 96 and 96% for V. fischeri, D. magna and Lepistes sp. in the effluent of the sequential system treating 150 mg/L AMX at HRTs of 2.25–5.5 days. Among the trophic organisms used in the acute toxicity tests the most sensitive organism was found to be bacteria (V. fischeri) while the most resistant organism was found to be fish (Lepistes sp.).

scholarly journals Removal of Reactive Blue 19 Dye Using a Combined Sonochemical and Modified Pistachio Shell Adsorption Processes from Aqueous Solutions

2018 ◽  
Author(s):  
Somayeh Rahdar ◽  
Leila Shikh ◽  
Shahin Ahmadi
Keyword(s):  
Aqueous Solution ◽  
Experimental Study ◽  
Aqueous Solutions ◽  
Polluted Water ◽  
Optimal Conditions ◽  
Combined Process ◽  
Pistachio Shell ◽  
Reactive Blue 19 ◽  
Adsorption Processes ◽  
Sonochemical Oxidation

Background and purpose: Reactive Blue 19(RB19) dye is one of the major dangers to human health and environment. Hence, the removal of these compounds from polluted water has been considered. This study was an attempt to investigate the removal of RB19 dye from aqueous solution in the presence of modified pistachio shell.Materials and Methods: In this experimental study, the treatability of water polluted with RB19dye was investigated by using sonochemical oxidation in a reactor. The sample with the desired concentrations of dye (10-80 mg/L) at pH 2-11 was prepared, then the required concentrations of MPS (0.1– 1.2 g/L) was flowed into the reactor intermittently.Results: The results of the current study showed that 40.26% of the dye was removed in the presence of MPS after 20 min at pH 2, MPS dose 0.7 g/L, and concentration of 20 mg/L.Conclusion: The findings showed that the combined process of ultrasonic and adsorption in the presence of MPS at optimal conditions of operation can be used as an acceptable option in the removal of dye from waters.

Acute Toxicity Testing with Juvenile White Sturgeon (Acipenser transmontanus)

1998 ◽  
Vol 33 (1) ◽  
pp. 95-110 ◽  
Author(s):  
W.R. Bennett ◽  
A.P. Farrell
Keyword(s):  
Acute Toxicity ◽  
Swimming Performance ◽  
Juvenile Fish ◽  
Toxicity Testing ◽  
White Sturgeon ◽  
Acipenser Transmontanus ◽  
Toxicity Tests ◽  
Fraser River ◽  
Acute Toxicity Tests ◽  
Acute Toxicity Testing

Abstract The primary goal of this study was to investigate the possibility of using early life stages of white sturgeon (Acipenser transmontanus) (eggs, larvae and fry) as a species relevant to the Fraser River, B.C., for the acute and sublethal toxico-logical testing of forest industry effluents. Here we report the first successful acute toxicity tests for 8-day-old larvae and 42-day-old fry exposed to several chemicals known to be released into the Fraser River (i.e., 6 monochlorovanillin [6 MVAN], 4,5 dichloroguaiacol [4,5 DCG], 4,5 dichlorocatechol [4,5 DCAT], pentachlorophenol [PCP], and didecyldimethylammonium chloride [DDAC]). In most cases, white sturgeon fry were at the lower end of the range for acute toxicity values for chlorinated phenolic compounds, when compared with other juvenile fish species, and they were extremely sensitive to DDAC. The larval stage was usually more sensitive than the fry stage. Acute toxicity tests with fertilized eggs were unsuccessful. A postexposure growth study was inconclusive because neither control nor toxicant-exposed larvae and fry withstood the additional handling used for measuring body mass. At 62-days-old, fry were more tolerant of handling. This allowed measurement of their swimming performance. Although we have concerns about the reliability of using larvae for acute toxicity testing at this time, 60-day-old white sturgeon fry would appear to be both a sensitive and relevant species for assessing environmental impacts relevant to the Fraser River.

The effects of contaminated sediments of the Blesbok Spruit near Witbank on water quality and the toxicity thereof to Daphnia pulex

1999 ◽  
Vol 39 (10-11) ◽  
pp. 173-176 ◽  
Author(s):  
Liesl Hill ◽  
Sebastian Jooste
Keyword(s):  
Surface Water ◽  
Mine Drainage ◽  
Interstitial Water ◽  
Stream Water ◽  
Daphnia Pulex ◽  
Contaminated Sediments ◽  
Toxicity Tests ◽  
Major Route ◽  
Acute Toxicity Tests ◽  
Route Of Exposure

With the increasing focus on environmental issues, the objective of this study is to evaluate the potential impact of contaminated sediments of the Blesbok Spruit near Witbank - which receives acid mine drainage (AMD) inter alia - on biota. Direct transfer of chemicals from sediments to organisms is considered to be a major route of exposure for many species, and therefore focusing attention on sediment contamination and highlighting the fact that sediments are an important resource. Acute toxicity tests were performed on Daphnia pulex using both extracted sediment interstitial water and surface water. Chemical analyses were also performed on the sediment, interstitial water and surface water samples. The toxicity results suggest that metal toxicity adds significantly to the toxicity of the stream water which is enhanced by the effect of pH. The pH of the stream and interstitial water was consistently below 4.5.

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