scholarly journals Decoloration of waste PET alcoholysis liquid by an electrochemical method

2018 ◽  
Vol 77 (10) ◽  
pp. 2463-2473
Author(s):  
Yanyan Li ◽  
Mengjuan Li ◽  
Jing Lu ◽  
Xiaoqiang Li ◽  
Mingqiao Ge
Keyword(s):  
Current Density ◽  
Degradation Mechanism ◽  
Statistical Design ◽  
Optimal Conditions ◽  
Liquid Chromatography Mass Spectrometry ◽  
Visible Absorption ◽  
Initial Ph ◽  
Predicted Model ◽  
Catalyst Dosage ◽  
Main Operating

Abstract Disperse Red 60 simulated polyester alcoholysis liquid decoloration by electro-Fenton with Fe3O4 catalyst was studied. The influences of the main operating parameters such as catalyst dosage (0.3–0.9 g/L), current density (60–120 mA/cm2) and pH (1–7) were optimized by response surface methodology (RSM) based on Box–Behnken surface statistical design (BBD). In optimal conditions, the initial concentration of 25 mg/L disperse red polyester alcoholysis liquid was catalyzed by 0.6 g/L Fe3O4, and the decoloration efficiency was 97.18% with the current density of 90 mA/cm2 and initial pH of 4.6. There was a relative error of 1.18% with the predicted model when the predictive value was 98.25% under the same conditions. In addition, ultraviolet-visible absorption spectra (UV-Vis), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) were used to study the degradation mechanism during decoloration. The intermediates were identified and the proposed degradation pathways were investigated by liquid chromatography-mass spectrometry (LC-MS) analysis.

The Study of Phosphorus Removal by Electrocoagulation with Iron-Anodes

2011 ◽  
Vol 183-185 ◽  
pp. 417-421
Author(s):  
Yong Bo Lin ◽  
Yang Yang ◽  
Shuai Wang
Keyword(s):  
Reaction Time ◽  
Total Phosphorus ◽  
Current Density ◽  
Phosphorus Removal ◽  
Removal Rate ◽  
Electrolysis Time ◽  
Optimal Conditions ◽  
Reaction Conditions ◽  
Electrode Distance ◽  
Initial Ph

Determined to adopt iron as anodes, and Ti-base board with coating as cathodes. To optimize the reaction conditions of phosphorus removal by electrocoagulation (EC), testing the effect of current density, electrode distance, initial pH and electrolysis time on the phosphorus removal. According to the results, the optimal conditions for the phosphorus removal in the EC treatment were obtained, i.e., 20 mA/cm2 of current density, 2cm of distance and 10min of reaction time were optimum. Under these conditions, phosphorus removal by electrocoagulation reached to 95.07%, 10min later the change of total phosphorus (TP) removal rate is not obvious. By the end of this test, phosphorus removal by electrocoagulation reached to 99.68%.

Heterogeneous electro-Fenton oxidation of azo dye methyl orange catalyzed by magnetic Fe3O4 nanoparticles

2016 ◽  
Vol 74 (5) ◽  
pp. 1116-1126 ◽  
Author(s):  
Hao Jiang ◽  
Yabing Sun ◽  
Jingwei Feng ◽  
Jian Wang
Keyword(s):  
Methyl Orange ◽  
Current Density ◽  
Azo Dye ◽  
Aeration Rate ◽  
Triple Quadrupole Mass Spectrometer ◽  
Liquid Chromatograph ◽  
Total Organic Carbon Removal ◽  
Initial Ph ◽  
Catalyst Dosage ◽  
Nano Fe3o4

Azo dye methyl orange (MO) degradation by heterogeneous electro-Fenton (EF) with a magnetic nano-Fe3O4 catalyst was investigated. In this study, Fe3O4 was synthesized by a coprecipitation method and characterized by X-ray diffraction and scanning electron microscopy. The influences of the main operating parameters such as current density, pH, catalyst dosage and aeration rate were studied. The results revealed that higher current density, catalyst dosage and aeration rate facilitated the degradation of MO, whereas the degradation efficiency of MO was decreased with an increase in the initial pH. After 90 min EF process, the volume of 500 mL, the initial concentration of 50 mg L−1 MO solution could be degraded by 86.6% with the addition of 1 g L−1 Fe3O4 under the current density of 10 mA cm−2 and pH 3, compared with 69.5% for the electrolytic process alone. Meanwhile, a total organic carbon removal of 32% was obtained, up to 35.5 mg L−1 accumulated H2O2 and less than 3.5 mg L−1 Fe leaching were detected. Moreover, based on the results of natural bond orbital (at B3LYP/6-311G (d, p)) and liquid chromatograph-triple quadrupole mass spectrometer analysis, nine intermediates were identified and the proposed degradation pathways were investigated.

scholarly journals Acute toxicity test under optimal conditions of two commercial reactive dyes using the Fenton-like process: Assessment of process factors by Box–Behnken design

2021 ◽  
Author(s):  
Natwat Srik ◽  
Arthit Neramittagapong ◽  
Pongsert Srip ◽  
Sutasinee Neramittagapong ◽  
Somnuk Theerakulpisut ◽  
...  
Keyword(s):  
Acute Toxicity ◽  
Optimal Condition ◽  
Dye Degradation ◽  
Reactive Dyes ◽  
Toxicity Tests ◽  
Optimal Conditions ◽  
Box Behnken Design ◽  
Initial Ph ◽  
Catalyst Dosage ◽  
Process Factors

Abstract Reactive dye has generally been used in woven cotton fabric dyeing industries. Some treatments of several reactive dyes may produce more toxicity than the original dyes. The objectives of this study were to find the optimal condition on dye degradation efficiency of commercial reactive red dye 36 (DR36) and reactive violet dye 30 (DV30) using Fenton-like reaction, and to determine acute toxicity by static bioassay method under the optimal condition. The experiment was designed by Box Behnken Design (BBD), in which an initial pH, catalyst dosage and initial concentration of H2O2 were considered as independent variables. The results showed that only an initial pH solution was the principal parameter which influenced decolorization of the reactive dyes. Other factors were much less significant. The optimal conditions were found to be given by pH 3, 1 g/L of catalyst dosage, 27.63 mM of concentration of H2O2 for DR36, and pH 3, 1.35 g/L of catalyst dosage, 45 mM of concentration of H2O2 for DV30. Ninety percent of both decolorization were achieved in 30 min. Acute toxicity tests of the treated solutions using freshwater fairy shrimps (Streptocephalus sirindhornae) revealed that the shrimps survived longer than 24 h, indicating that the treated solutions were not acutely toxic. The average leaked iron, ADMI value and total organic carbon were found to be less than 10 ppm, 5 ADMI and 9.17 ppm respectively, in the treated samples. This research demonstrated an efficient method for decolorization of the reactive dyes with low acute toxicity.

Advanced Treatment of Coking Wastewater by Electro-Coagulation

2014 ◽  
Vol 700 ◽  
pp. 426-430 ◽  
Author(s):  
Hai Tang ◽  
Jun Peng Sha ◽  
Yang Long Ou ◽  
Xiang Zhao
Keyword(s):  
Reaction Time ◽  
Current Density ◽  
Color Removal ◽  
Advanced Treatment ◽  
Coking Wastewater ◽  
Degradation Behavior ◽  
Optimal Conditions ◽  
Initial Ph ◽  
Electro Coagulation

The degradation behavior and mechanism of biologically pretreated coking wastewater (BPCW) were investigated by means of a lab-scale electro-coagulation (EC) in static methods. The results showed that the percent COD and color removal can reach 80.5 % and 95.4 % respectively under the optimal conditions (initial pH of 8.0; reaction time of 30 min; current density of 14.0 mA/cm2 and NaCl dosage 1.6 g/L).

Decolorization of Crystal Violet by ultrasound/heterogeneous Fenton process

2013 ◽  
Vol 68 (11) ◽  
pp. 2515-2520 ◽  
Author(s):  
Hui Zhang ◽  
Hong Gao ◽  
Chun Cai ◽  
Chunyang Zhang ◽  
Lu Chen
Keyword(s):  
Crystal Violet ◽  
Ph Value ◽  
Catalyst Stability ◽  
Fenton Process ◽  
Optimal Conditions ◽  
Heterogeneous Fenton ◽  
Decolorization Efficiency ◽  
Initial Ph ◽  
Iron Leaching ◽  
Catalyst Dosage

Activated-carbon-supported iron oxides were prepared and used as a catalyst in an integrated ultrasound/heterogeneous Fenton process for the decolorization of Crystal Violet. A synergistic effect was observed when ultrasound was combined with the heterogeneous Fenton process. The decolorization efficiency increased with the increasing power density and catalyst dosage, but decreased with the increase of initial pH value. There exists an optimal hydrogen peroxide concentration for decolorization. Catalyst stability was evaluated by measuring iron leaching in solution. The decolorization efficiency was 88% under the optimal conditions. Toxicity test with Daphnia magna showed that the acute toxicity of dye solution decreased significantly after the treatment by the heterogeneous sono-Fenton process.

Reduction of Acquisition Time for RIL, SDL, and LADA

2007 ◽  
Author(s):  
Arjan Mels ◽  
Frank Zachariasse
Keyword(s):  
Background Noise ◽  
Signal Strength ◽  
Acquisition Time ◽  
Optimal Conditions ◽  
Signal Collection ◽  
Defect Localization ◽  
Model Equations ◽  
Set Up ◽  
Main Operating ◽  
Quantitative Tool

Abstract Although RIL, SDL and LADA are slightly different, the main operating principle is the same and the theory for defect localization presented in this paper is applicable to all three methods. Throughout this paper the authors refer to LADA, as all experimental results in this paper were obtained with a 1064nm laser on defect free circuits. This paper first defines mathematically what 'signal strength' actually means in LADA and then demonstrates a statistical model of the LADA situation that explains the optimal conditions for signal collection and the parameters involved. The model is tested against experimental data and is also used to optimise the acquisition time. Through this model, equations were derived for the acquisition time needed to discern a LADA response from the background noise. The model offers a quantitative tool to estimate the feasibility of a given LADA measurement and a guide to optimising the required experimental set-up.

scholarly journals Removal of Pb, Cu, Cd, and Zn Present in Aqueous Solution Using Coupled Electrocoagulation-Phytoremediation Treatment

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Francisco Ferniza-García ◽  
Araceli Amaya-Chávez ◽  
Gabriela Roa-Morales ◽  
Carlos E. Barrera-Díaz
Keyword(s):  
Aqueous Solution ◽  
Current Density ◽  
Batch Reactor ◽  
Operating Time ◽  
Typha Latifolia ◽  
Optimal Conditions ◽  
Lead And Zinc ◽  
Parallel Arrangement ◽  
Aluminum Electrodes ◽  
Cadmium Lead

This study presents the results of a coupled electrocoagulation-phytoremediation treatment for the reduction of copper, cadmium, lead, and zinc, present in aqueous solution. The electrocoagulation was carried out in a batch reactor using aluminum electrodes in parallel arrangement; the optimal conditions were current density of 8 mA/cm2 and operating time of 180 minutes. For phytoremediation the macrophytes, Typha latifolia L., were used during seven days of treatment. The results indicated that the coupled treatment reduced metal concentrations by 99.2% Cu, 81.3% Cd, and 99.4% Pb, while Zn increased due to the natural concentrations of the plant used.

Electrochemical Treatment of Simulated Dye Wastewater

2012 ◽  
Vol 441 ◽  
pp. 555-558
Author(s):  
Feng Tao Chen ◽  
San Chuan Yu ◽  
Xing Qiong Mu ◽  
Shi Shen Zhang
Keyword(s):  
Current Density ◽  
Oxygen Demand ◽  
Electrochemical Treatment ◽  
Dye Wastewater ◽  
Electrolysis Time ◽  
Electrochemical Degradation ◽  
Mild Conditions ◽  
Thermal Decomposition Method ◽  
Initial Ph ◽  
Effects Of Ph

The Ti/SnO2-Sb2O3/PbO2 electrodes were prepared by thermal decomposition method and its application in the electrochemical degradation of a heteropolyaromatic dye, Methylene blue (MB), contained in simulated dye wastewater were investigated under mild conditions. The effects of pH, current density and electrolysis time on de-colorization efficiency were also studied. Chemical oxygen demand (COD) was selected as another parameter to evaluate the efficiency of this degradation method on treatment of MB wastewater. The results revealed that when initial pH was 6.0, current density was 50 mA·cm2, electrolysis time was 60 min, Na2SO4 as electrolyte and its concentration was 3.0 g·dm3, the de-colorization and COD removal efficiency can reach 89.9% and 71.7%, respectively.

Removal of phenol from steel wastewater by combined electrocoagulation with photo-Fenton

2018 ◽  
Vol 78 (6) ◽  
pp. 1260-1267 ◽  
Author(s):  
Mohammad Malakootian ◽  
Mohammad Reza Heidari
Keyword(s):  
Reaction Time ◽  
Removal Efficiency ◽  
Current Density ◽  
Steel Industry ◽  
High Efficiency ◽  
Oxygen Demand ◽  
Optimal Conditions ◽  
Suitable Alternative ◽  
Steel Mills ◽  
Real Wastewater

Abstract Phenol and its derivatives are available in various industries such as refineries, coking plants, steel mills, drugs, pesticides, paints, plastics, explosives and herbicides industries. This substance is carcinogenic and highly toxic to humans. The purpose of the study was to investigate the removal of phenol from wastewater of the steel industry using the electrocoagulation–photo-Fenton (EC-PF) process. Phenol and chemical oxygen demand (COD) removal efficiency were investigated using the parameters pH, Fe2+/H2O2, reaction time and current density. The highest removal efficiency rates of phenol and COD were 100 and 98%, respectively, for real wastewater under optimal conditions of pH = 4, current density = 1.5 mA/cm2, Fe2+/H2O2 = 1.5 and reaction time of 25 min. Combination of the two effective methods for the removal of phenol and COD, photocatalytic electrocoagulation photo-Fenton process is a suitable alternative for the removal of organic pollutants in industry wastewater because of the low consumption of chemicals, absence of sludge and other side products, and its high efficiency.

scholarly journals Application of a Continuous Bipolar Mode Electrocoagulation (CBME) system for polishing distillery wastewater

2019 ◽  
Vol 93 ◽  
pp. 02005 ◽  
Author(s):  
Madhuri Damaraju ◽  
Debraj Bhattacharyya ◽  
Tarun Panda ◽  
Kiran Kumar Kurilla
Keyword(s):  
Reaction Time ◽  
Current Density ◽  
Optimal Point ◽  
Suitable Alternative ◽  
Toc Removal ◽  
Bipolar Mode ◽  
Recalcitrant Carbon ◽  
Initial Ph ◽  
Distillery Wastewater ◽  
Experimental Values

A continuous bipolar mode electrocoagulation (CBME) unit was used in this study for polishing a biologically treated distillery wastewater at laboratory scale. This study focuses on optimizing the process for removal of Total Organic Carbon (TOC) from an anaerobically-treated distillery wastewater. Response surface methodology (RSM) was used for optimizing the process. The study was conducted by varying three operating parameters: Initial pH (2-10), reaction time (0.5-15 min), and current density (13-40 A/sqm). High R-square values, above 0.9, were obtained with ANOVA. Optimal point was observed to be at pH-6.04, Reaction time-11.63 min, current density-39.2 A/sqm. Experimental values of TOC removal at optimal point were found to be 73% against maximum predicted value of 79%. Color removal efficiency was observed to be 85% at the optimal points. It can be concluded that CBME system can be a suitable alternative for removal of recalcitrant carbon and color post-biological treatment in distillery wastewaters.

Sign in / Sign up

Export Citation Format

Share Document