Study on the Treatment of High Concentration Dye Wastewater on Modified Active Carbon Cloth Electrode

2011 ◽  
Vol 347-353 ◽  
pp. 1869-1873 ◽  
Author(s):  
Hong Xia

In this study, for the first time nanostructured TiO2 and Fe2O3 was loaded on active carbon cloth (ACC) as electrodes to be used in an electrochemical oxidation system. This novel TiO2-ACC and Fe2O3 / TiO2-ACC composite electrodes(or modified electrodes) were characterized by scanning electronmicroscopy (SEM)and cyclic voltammetry(CV).During the degradation of dye wastewater, electrochemical oxidation system with TiO2-ACC and Fe2O3 / TiO2-ACC electrodes showed much higher activity than with ACC electrodes. The system with Fe2O3 / TiO2-ACC electrodes acquired the best COD removal: the COD of wastewater decreased from 33000 mg/L to 8700mg/L. The removal rate of COD reached 74%, which was 19% higher than ACC system.

2019 ◽  
Vol 19 (11) ◽  
pp. 7308-7314
Author(s):  
Jinyan Li ◽  
Qingsong Guan ◽  
Junming Hong ◽  
Chang-Tang Chang

Composite electrodes with different graphene (GN)/TiO2 ratios and nano-activated carbon electrodes were prepared for electrocatalytic performance comparison. The electrodes were loaded with platinum (Pt) by use of chloroplatinic acid to promote their performance. Reactive Black 5 (RBk5) dye wastewater was treated as a challenging pollutant by use of advanced electrochemical oxidation technology. The composite materials were characterized by Transmission Electron Microscope (TEM), Field Emission Scanning Electron Microscopy (FE-SEM), and Energy Disperse Spectroscopy (EDS). Results showed that the graphene electrode was prepared successfully and verified because all elements were uniformly loaded on the conductive carbon cloth. The effects of several operating parameters including material types, pH, initial concentration of RBk5, and current density on the removal performance of RBk5 were also assessed. The supporting electrolyte was NaCl solution of 1 g L−1. The concentration of RBk5 was detected using an ultraviolet spectrophotometer with a detection wavelength of 600 nm. The optimum parameters of the experiment were GN/TiO2 ratio of 1:4 and pH of 6.6. The removal efficiency of RBk5 could be higher than 95% under an initial concentration of RBk5 of 5 ppm and a current density of 2.5 mA·cm-2 when reaction time was 30 min.


2020 ◽  
Vol 13 (1) ◽  
pp. 126
Author(s):  
Guozhen Zhang ◽  
Xingxing Huang ◽  
Jinye Ma ◽  
Fuping Wu ◽  
Tianhong Zhou

Electrochemical oxidation technology is an effective technique to treat high-concentration wastewater, which can directly oxidize refractory pollutants into simple inorganic compounds such as H2O and CO2. In this work, two-dimensionally stable anodes, Ti/RuO2-IrO2-SnO2, have been developed in order to degrade organic pollutants from pharmaceutical wastewater. Characterization by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) showed that the oxide coating was successfully fabricated on the Ti plate surface. Electrocatalytic oxidation conditions of high concentration pharmaceutical wastewater was discussed and optimized, and the best results showed that the COD removal rate was 95.92% with the energy consumption was 58.09 kW·h/kgCOD under the electrode distance of 3 cm, current density of 8 mA/cm2, initial pH of 2, and air flow of 18 L/min.


Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 156
Author(s):  
Manjing Lu ◽  
Jiaqi Wang ◽  
Yuzhong Wang ◽  
Zhengguang He

Chemical synthetic pharmaceutical wastewater has characteristics of high concentration, high toxicity and poor biodegradability, so it is difficult to directly biodegrade. We used acid modified attapulgite (ATP) supported Fe-Mn-Cu polymetallic oxide as catalyst for multi-phase Fenton-like ultraviolet photocatalytic oxidation (photo-Fenton) treatment with actual chemical synthetic pharmaceutical wastewater as the treatment object. The results showed that at the initial pH of 2.0, light distance of 20 cm, and catalyst dosage and hydrogen peroxide concentration of 10.0 g/L and 0.5 mol/L respectively, the COD removal rate of wastewater reached 65% and BOD5/COD increased to 0.387 when the reaction lasted for 180 min. The results of gas chromatography-mass spectrometry (GC-MS) indicated that Fenton-like reaction with Fe-Mn-Cu@ATP had good catalytic potential and significant synergistic effect, and could remove almost all heterocycle compounds well. 3D-EEM (3D electron microscope) fluorescence spectra showed that the fluorescence intensity decreased significantly during catalytic degradation, and the UV humus-like and fulvic acid were effectively removed. The degradation efficiency of the nanocomposite only decreased by 5.8% after repeated use for 6 cycles. It seems appropriate to use this process as a pre-treatment for actual pharmaceutical wastewater to facilitate further biological treatment.


2012 ◽  
Vol 627 ◽  
pp. 378-381
Author(s):  
Bi Rong Wang

Fenton pretreatment has been used for treating dye wastewater. The effects of the dos of H2O2 and FeSO4, reaction time and pH on the removal COD were investigated. It was found that, when the reaction conditions are as follows: COD 2850 mg/L dyeing wastewater, the dosage of H2O2 is 140mmol/L, FeSO4 17.02 mmol/L, pH 7.6, and reaction time 1.0 h, the CODcr of dye wastewater removal rate of up to 70%. Fenton pretreatment process of dye wastewater has a broad prospect.


1998 ◽  
Vol 38 (3) ◽  
pp. 95-102 ◽  
Author(s):  
G. Mazzolani ◽  
F. Pirozzi ◽  
G. d'Antonoi

Numerical models for the prediction of turbulent flow field and suspended solid distribution in sedimentation tanks are characterized by refined modeling of hydrodynamics, but apparently weak modeling of settling properties of suspensions. It is known that sedimentation tanks typically treat highly heterodisperse suspensions, whose concentrations range from relatively high to low values. However, settling is modeled either by considering one or more particle classes of different settling velocity, without accounting for hindered settling conditions, or by treating the suspension as monodisperse, even in regions of low concentration. A new generalized settling model is proposed to account for both discrete settling conditions in low concentration regions of the tanks and hindered settling conditions in high concentration regions. Settling velocities of heterodisperse suspensions are then determined as a function of particle velocities in isolation and their total concentration. The settling model is used in the framework of a transport model for the simulation of hydrodynamics and solid distribution in a rectangular sedimentation tank. Results show that solid distribution is mainly affected by particle interactions in the inlet region and by settling properties of individual particles in the outlet region. Comparison of the proposed settling model with other settling models suggests that a generalized approach of the modeling of settling properties of suspensions is a primary concern to obtain reliable predictions of the removal rate.


2014 ◽  
Vol 1044-1045 ◽  
pp. 215-218
Author(s):  
Xian Huan Qiu ◽  
Hai Yu ◽  
Peng Fei Deng

In the presence of acetic acid, the effects of pH, processing time, addition of Fe2+ and H2O2 on dye wastewater treatment were studied. Experimental results showed that in the presence of acetic acid, when the pH value was 4, the processing time was 30.0min, addition of ferrous sulfate was 4.8g/L, and addition of hydrogen peroxide was 56mL/L, the treatment effect was the best, COD removal rate reached 51.0%. Further studied of the effect of the presence of acetic acid on Fenton’s oxidation of dye wastewater, the results showed that without of acetic acid, the COD removal rate was higher than that with acetic acid. And the effect of Fenton's reagent on oxidation of dye substances was interfered by the presence of acetic acid.


2021 ◽  
Vol 39 (2A) ◽  
pp. 189-195
Author(s):  
Shaimaa T. Alnasrawy ◽  
Ghayda Y. Alkindi ◽  
Taleb M. Albayati

In this study, the ability of the electrochemical process to remove aqueous high concentration phenol using an electrochemical cell with aluminum anode and cathode was examined. The removal rate of phenol was monitored using different parameters phenol concentration, pH, electrolysis time, current density, and electrode distance. Obtained results indicated that the low removal rates of phenol were observed at both low and high pH. However, the removal rate of phenol increased with an increase in the current density, each electrochemical process conditions need a certain electrodes distance. removal rate of phenol decreased with the increase in the initial phenol concentration. The maximum removal rate of phenol obtained from this study was 82%.


Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1803 ◽  
Author(s):  
Yuko Goto ◽  
Naoko Yoshida

Conventional aerobic treatment of swine wastewater, which generally contains 4500–8200 mg L−1 of organic matter, is energy-consuming. The aim of this study was to assess the application of scaled-up microbial fuel cells (MFCs) with different capacities (i.e., 1.5 L, 12 L, and 100 L) for removing organic matter from swine wastewater. The MFCs were single-chambered, consisting of an anode of microbially reduced graphene oxide (rGO) and an air-cathode of platinum-coated carbon cloth. The MFCs were polarized via an external resistance of 3–10 Ω for 40 days for the 1.5 L-MFC and 120 days for the 12L- and 100 L-MFC. The MFCs were operated in continuous flow mode (hydraulic retention time: 3–5 days). The 100 L-MFC achieved an average chemical oxygen demand (COD) removal efficiency of 52%, which corresponded to a COD removal rate of 530 mg L−1 d−1. Moreover, the 100 L-MFC showed an average and maximum electricity generation of 0.6 and 2.2 Wh m−3, respectively. Our findings suggest that MFCs can effectively be used for swine wastewater treatment coupled with the simultaneous generation of electricity.


2020 ◽  
Vol 49 (1) ◽  
pp. 46-54 ◽  
Author(s):  
Wei Zhang ◽  
Weiwei Lv ◽  
Xiaoyan Li ◽  
Jiming Yao

Purpose In this study, the oxidative degradation performance of indigo wastewater based on electrochemical systems was explored. The decolourization degrees, removal rate of chemical oxygen demand and biochemical oxygen demand of the indigo wastewater after degradation were evaluated and optimized treatment conditions being obtained. Design/methodology/approach The single factor method was first used to select the electrolyte system and electrode materials. Then the response surface analysis based on Box–Behnken Design was chosen to determine the influence of four independent variables such as FeCl3 concentration, NaCl concentration, decolourization time and voltage on the degradation efficiency. Findings On the basis of single factor experiment, the electrode material of stainless steel was selected in the double cell, and the indigo wastewater was electrolyzed with FeCl3 and NaCl electrolytes. The process conditions of electrochemical degradation of indigo wastewater were optimized by response surface analysis: the concentration of FeCl3 and NaCl was of 16 and 9 g/L, respectively, with a decolourization time of 50 min, voltage of 10 V and decolourization percentage of 98.94. The maximum removal rate of chemical oxygen demand reached 75.46 per cent. The highest ratio of B/C was 3.77, which was considered to be more biodegradable. Research limitations/implications Dyeing wastewater is bringing out more and more pollution problems to the environment. However, there are some shortcomings in traditional technologies such as adsorption and filtration. As a kind of efficient and clean water treatment technology, electrochemical oxidation has been applied to the treatments of various types of wastewater. The decolourization and degradation of indigo wastewater is taken as an example to provide reference for the treatment of wastewater in actual plants. Practical implications The developed method provided a simple and practical solution for efficiently degrading indigo wastewater. Originality/value The method for the electrochemical oxidation technology was novel and could find numerous applications in the degradation of printing and dyeing wastewater.


RSC Advances ◽  
2019 ◽  
Vol 9 (66) ◽  
pp. 38414-38421 ◽  
Author(s):  
Sharafat Ali ◽  
Zhijun Li ◽  
Wajid Ali ◽  
Ziqing Zhang ◽  
Mingzhuo Wei ◽  
...  

Au decorated three-phase-mixed nanosized TiO2 coupled with phosphate-treated AC as recyclable nanocomposite photocatalysts exhibit excellent photoactivity for degrading high-concentration 2, 4-DCP, mainly due to the improved charge separation and specific surface area.


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