Electrochemical removal of carbamazepine in water with Ti/PbO2 cylindrical mesh anode

2015 ◽  
Vol 73 (5) ◽  
pp. 1155-1165 ◽  
Author(s):  
J. D. García-Espinoza ◽  
P. Gortáres-Moroyoqui ◽  
M. T. Orta-Ledesma ◽  
P. Drogui ◽  
P. Mijaylova-Nacheva
Keyword(s):  
Supporting Electrolyte ◽  
Oxygen Demand ◽  
Electrochemical Reactor ◽  
Operating Conditions ◽  
Current Intensity ◽  
Oxygen Flux ◽  
Order Kinetic ◽  
Electrolysis Time ◽  
Direct Oxidation

Carbamazepine (CBZ) is one of the most frequently detected organic compounds in the aquatic environment. Due to its bio-persistence and toxicity for humans and the environment its removal has become an important issue. The performance of the electrochemical oxidation process and in situ production of reactive oxygen species (ROS), such as O3 and H2O2, for CBZ removal have been studied using Ti/PbO2 cylindrical mesh anode in the presence of Na2SO4 as supporting electrolyte in a batch electrochemical reactor. In this integrated process, direct oxidation at anode and indirect oxidation by in situ electrogenerated ROS can occur simultaneously. The effect of several factors such as electrolysis time, current intensity, initial pH and oxygen flux was investigated by means of an experimental design methodology, using a 24 factorial matrix. CBZ removal of 83.93% was obtained and the most influential parameters turned out to be electrolysis time, current intensity and oxygen flux. Later, the optimal experimental values for CBZ degradation were obtained by means of a central composite design. The best operating conditions, analyzed by Design Expert® software, are the following: 110 min of electrolysis at 3.0 A, pH = 7.05 and 2.8 L O2/min. Under these optimal conditions, the model prediction (82.44%) fits very well with the experimental response (83.90 ± 0.8%). Furthermore, chemical oxygen demand decrease was quantified. Our results illustrated significant removal efficiency for the CBZ in optimized condition with second order kinetic reaction.

scholarly journals Optimization of textile azo dye degradation by electrochemical oxidation using Box-Behnken Design

2019 ◽  
Vol 8 (5) ◽  
pp. 410-419 ◽  
Author(s):  
Kaouthar Oukili ◽  
Mohammed Loukili
Keyword(s):  
Azo Dye ◽  
Dye Degradation ◽  
Electrochemical Reactor ◽  
Operating Conditions ◽  
Color Removal ◽  
Current Intensity ◽  
Quadratic Model ◽  
Electrolysis Time ◽  
Box Behnken Design ◽  
Initial Ph

Degradation of textile azo dye solutions containing Methyl Orange by anodic oxidation using an electrochemical reactor was studied. The combined effect of independent parameters (current intensity, initial pH and electrolysis time) on color removal efficiency was investigated and optimized using response surface methodology. A Box-Behnken design was successfully employed for experimental design. The obtained quadratic model was statistically tested using analysis of variance (ANOVA). Results showed that the optimal operating conditions to achieve 98.51% efficiency for color removal were current intensity = 4.6 A, initial pH= 4 and electrolysis time = 65 min, at a dye concentration and temperature of 50 mg/L and 25 °C, respectively. 

scholarly journals Removal of organic pollutants from produced water by batch adsorption treatment

2021 ◽  
Author(s):  
Eman Hashim Khader ◽  
Thamer Jassim Mohammed ◽  
Nourollah Mirghaffari ◽  
Ali Dawood Salman ◽  
Tatjána Juzsakova ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Produced Water ◽  
Oxygen Demand ◽  
Powdered Activated Carbon ◽  
Pollutant Removal ◽  
Operating Conditions ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Zeolite X

AbstractThis paper studied the adsorption of chemical oxygen demand (COD), oil and turbidity of the produced water (PW) which accompanies the production and reconnaissance of oil after treating utilizing powdered activated carbon (PAC), clinoptilolite natural zeolite (CNZ) and synthetic zeolite type X (XSZ). Moreover, the paper deals with the comparison of pollutant removal over different adsorbents. Adsorption was executed in a batch adsorption system. The effects of adsorbent dosage, time, pH, oil concentration and temperature were studied in order to find the best operating conditions. The adsorption isotherm models of Langmuir, Freundlich and Temkin were investigated. Using pseudo-first-order and pseudo-second-order kinetic models, the kinetics of oil sorption and the shift in COD content on PAC and CNZ were investigated. At a PAC adsorbent dose of 0.25 g/100 mL, maximum oil removal efficiencies (99.57, 95.87 and 99.84 percent), COD and total petroleum hydrocarbon (TPH) were identified. Moreover, when zeolite X was used at a concentration of 0.25 g/100 mL, the highest turbidity removal efficiency (99.97%) was achieved. It is not dissimilar to what you would get with PAC (99.65 percent). In comparison with zeolites, the findings showed that adsorption over PAC is the most powerful method for removing organic contaminants from PW. In addition, recycling of the consumed adsorbents was carried out in this study to see whether the adsorbents could be reused. Chemical and thermal treatment will effectively regenerate and reuse powdered activated carbon and zeolites that have been eaten. Graphic abstract

Treatment of dairy wastewaters by electrocoagulation using iron electrodesTraitement des eaux résiduaires d'une laiterie par électrocoagulation avec des électrodes de fer

2014 ◽  
Vol 50 (2) ◽  
pp. 198-209 ◽  
Author(s):  
Malika Aoudjehane ◽  
Mohamed Elghazali Benatallah
Keyword(s):  
Electrical Conductivity ◽  
Removal Efficiency ◽  
Current Density ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Electrolysis Time ◽  
Electrode Consumption ◽  
Treatment Conditions ◽  
Consumption Energy ◽  
Optimal Efficiency

A procedure of electrocoagulation (EC) using iron electrodes has been used for the treatment of the wastewaters produced by the Beni-Tamou dairy in Algeria. The effect of the operating conditions, such as the current intensity, the electrolysis time, the pH of the solution and the electrical conductivity, on the removal efficiency of chemical oxygen demand (COD) and the total suspended solids (TSS) has been studied. An inter-electrode distance of 1 cm has been maintained constant during the tests. It has been found that an increase in electrolysis time and current density improved the treatment significantly, albeit with a greater consumption of energy as well as an increased electrode consumption. The results of the electrocoagulation treatment under various operating conditions show that the optimal efficiency has been obtained under the following conditions: 60 minutes of electrolysis, a current density of 200 A/m2, a pH 8, an electrical conductivity of 4.72 mS/cm and a consumption energy of 13.57 kWh/m3. Under these conditions, the removal efficiency for the COD and TSS parameters is 93.26 and 99.3%, respectively. The optimal treatment conditions of dairy wastewaters have resulted in final COD and TSS concentrations of 41.5 and 27 mg/L, respectively, values that are conform to industrial liquid effluents discharge norms.

Prediction Rules for Biogas Valorisation in Municipal Solid Waste Landfills

1993 ◽  
Vol 27 (2) ◽  
pp. 235-241 ◽  
Author(s):  
B. Marticorena ◽  
A. Attal ◽  
P. Camacho ◽  
J. Manem ◽  
D. Hesnault ◽  
...  
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Operating Conditions ◽  
Landfill Site ◽  
Order Kinetic ◽  
Methane Potential ◽  
Municipal Solid Waste Landfills ◽  
In Situ Decomposition ◽  
Solid Waste Landfills

The objective of this study was to develop a tool to predict the quantity of biogas produced by a municipal solid waste (MSW) landfill site to allow the energy it represents to be exploited. The model proposed is based on a first-order kinetic equation which describes the production of methane during in-situ decomposition of MSW. This equation was applied to a landfill site considering the MSW mass as a series of layers of waste of differing ages. The equation includes three parameters: MPo, the methane potential of fresh waste which is specific to MSW, d, the in-situ life duration of the waste which depends on the landfilling conditions and Ti, the filling rate, i.e. the rate at which waste is placed in the landfill site. This simple model, usable for all types of landfill and, by virtue of the parameters it uses, closely represents the site operating conditions. The approach was applied to the Villeparisis site and predicted a methane production rate of between 270 and 410 m3h−1, quite close to the measured value of 300 m3.h−1. In addition, the possibility of simulating variable landfill rates and waste life durations can be used to guide site management techniques to optimize the valorisation of the biogas and provide a global approach to the problem by incorporating leachate collection into the biogas exploitation calculations.

scholarly journals Degradation of an organophosphorus insecticide in aqueous medium by Electro-Fenton process

2021 ◽  
pp. 63-72
Author(s):  
Mirvet Assassi ◽  
Farid Madjene ◽  
Abdeltif Amrane
Keyword(s):  
Biological Treatment ◽  
Supporting Electrolyte ◽  
Operating Conditions ◽  
Organophosphorus Insecticide ◽  
Current Intensity ◽  
Fenton Process ◽  
Factors Affecting ◽  
Incomplete Removal ◽  
Temperature Solution ◽  
Major Factors

This work proposes the remediation of toxic and/or refractory pollutants, such as the organophosphorus insecticide (Phosmet) which cannot be completely degraded by conventional methods like biological treatment, adsorption, flocculation, electro-flocculation, reverse osmosis, ultrafiltration, coagulation. However, these techniques have some disadvantages such as incomplete removal, therefore, the Electro-Fenton process was used. The major factors affecting the removal of Phosmet, namely the current intensity, catalyst concentration (Fe3+), temperature solution, nature of the electrolytes and oxygenation duration of the solution were studied in this work. The optimal operating conditions appeared to be: current intensity 200 mA, 0.5 mmol L-1 of Fe3+, T= 20?C, pH =3 using Na2SO4 (50 mmol L-1) as supporting electrolyte and an oxygen supply throughout all the experiments (120 min). Under these optimal conditions, the removal efficiency of the phosmet was 88%.

Utilization of Oxygen Models in Environmental Impact Analysis

1977 ◽  
Vol 12 (1) ◽  
pp. 135-156 ◽  
Author(s):  
W.J. Snodgrass ◽  
M.F. Holloran
Keyword(s):  
Impact Analysis ◽  
Management Strategies ◽  
Oxygen Demand ◽  
Sediment Oxygen Demand ◽  
Order Kinetic ◽  
Temperature Model ◽  
One Dimensional ◽  
Order Kinetic Model ◽  
Anoxic Zones

Abstract A vertical one-dimensional temperature-oxygen model for reservoirs is used to estimate zones of stress on the aquatic environment of a series of reservoirs in Nova Scotia. Application to cold climates necessitated a few novel developments for the temperature model. The oxygen model whose sinks are water column decay and sediment oxygen demand (SOD) is calibrated using under ice measurements of oxygen stocks and laboratory and in situ measurements of a zero-order kinetic model for sediment oxygen demand. These extensive studies are complementary and indicate a winter SOD of 0.1 gm 02/m2/day and a higher summer value. High epilimnetic temperatures coupled with the predicted anoxic zones in lower waters cause a major stress upon fisheries potential. This model provides a tool for determining the effects of different reservoir management strategies upon water quality and for selecting among these strategies.

scholarly journals Decolorization of industrial wastewater using electrochemical peroxidation process

2021 ◽  
Author(s):  
Elin Marlina ◽  
Purwanto Purwanto ◽  
Sudarno Sudarno
Keyword(s):  
Hydrogen Peroxide ◽  
Chemical Oxygen Demand ◽  
Supporting Electrolyte ◽  
Paper Industry ◽  
Oxygen Demand ◽  
Current Intensity ◽  
Process Efficiency ◽  
Wastewater Sample ◽  
Sample Treatment ◽  
Reaction Cell

In this study, decolorization of wastewater samples taken from the paper industry is investigated using electrochemical peroxidation process. The electrochemical peroxidation process is a part of electrochemical advanced oxidation processes, which is based on the Fenton’s chemical reaction, provided by addition of external H2O2 into reaction cell. In this study, iron is used as anode and graphite as cathode put at the fixed distance of 30 mm in a glass reaction cell. The cell was filled with the solution containing wastewater and sodium chloride as the supporting electrolyte. Factors of the process such as pH, current intensity, hydrogen peroxide concentration, and time of treatment were studied. The results illustrate that all these parameters affect efficiencies of dye removal and chemical oxygen demand (COD) reducing. The maximal removal of wastewater contaminants was achieved under acid (pH 3) condition, with the applied current of 1 A, and hydrogen peroxide concentration of 0.033 M. At these conditions, decolorization process efficiency reached 100 and 83 % of COD removal after 40 minutes of wastewater sample treatment. In addition, the electrical energy consumption for wastewater treatment by electrochemical peroxidation is calculated, showing increase as the current intensity of treatment process was increased. The obtained results suggest that electrochemical peroxidation process can be used for removing dye compounds and chemical oxygen demand (COD) from industrial wastewaters with high removal efficiency.

scholarly journals Optimization of process parameters for the electrochemical oxidation treatment of petroleum refinery wastewater using porous graphite anode

2020 ◽  
Vol 13 (2) ◽  
pp. 125-135
Author(s):  
Ahmad Salah Fahim ◽  
Ali H. Abbar
Keyword(s):  
Removal Efficiency ◽  
Current Density ◽  
Petroleum Refinery ◽  
Oxygen Demand ◽  
Chloride Ion ◽  
Electrochemical Reactor ◽  
Electrochemical Treatment ◽  
Operating Conditions ◽  
Graphite Anode ◽  
Porous Graphite

The present paper deals with the electrochemical treatment of wastewaters generated from Al-Diwaniyah petroleum refinery plant in a batch electrochemical reactor using stainless steel cathode and porous graphite anode. Effects of operating parameters such as current density (5-25mA/cm2), pH (3-9), addition of NaCl (0-2g/l), and time (20–60min) on the removal efficiency of chemical oxygen demand (COD) were investigated. The results revealed that both pH and NaCl addition have the main effect on the COD removal efficiency confirming that the system was governed by reaction conditions in the bulk of solution not upon the electro oxidation of chloride ion on the surface of the electrode. Parametric optimization was carried out using Response Surface Methodology (RSM) combined with Box–Behnken Design (BBD) to maximize the removal of COD. Under optimized operating conditions of initial pH: 3, current density = 25 mA/cm2, NaCl conc.  = 2g/l, and time = 60 min, the removal efficiency of COD was found to be 98.16% with energy consumption of 9.85 kWh/kgCOD which is relatively lower than the previous works.

Photo-assisted electrochemical degradation of real textile wastewater

2010 ◽  
Vol 61 (2) ◽  
pp. 491-498 ◽  
Author(s):  
P. A. Alves ◽  
G. R. P. Malpass ◽  
H. D. Johansen ◽  
E. B. Azevedo ◽  
L. M. Gomes ◽  
...  
Keyword(s):  
Supporting Electrolyte ◽  
Oxygen Demand ◽  
Textile Wastewater ◽  
Operating Conditions ◽  
Cod Removal ◽  
Constant Current ◽  
Electrochemical Degradation ◽  
Figures Of Merit ◽  
Before And After ◽  
Initial Ph

In the present study, photo-assisted electrochemical degradation of real textile wastewater was performed. Degradation assays were performed at constant current (40 mA cm−2) in a combined electro/photochemical flow-cell using a Ti/Ru0.3Ti0.7O2 DSA® type electrode. The results show that the method is capable of removing color and chemical oxygen demand (COD) from the effluent. Additionally, the effect of initial pH and type of supporting electrolyte (Na2SO4 or NaCl) was investigated. The principal figures of merit used in this study were COD removal and color removal (605 nm). The results show that up to 72% color and up to 59% COD removal in 120 min is possible under the operating conditions employed. Studies of the phytotoxicity of the wastewater before and after the photo-assisted degradation assays are also presented and the results demonstrate that the toxicity of the effluent is dependent on the length of electrolysis time and the treatment procedure employed.

scholarly journals Fabrication and application of boron doped diamond BDD electrode in olive mill wastewater treatment in Jordan

2016 ◽  
Vol 7 (4) ◽  
pp. 502-510 ◽  
Author(s):  
Inshad Jum'h ◽  
Arwa Abdelhay ◽  
Hussein Al-Taani ◽  
Ahmad Telfah ◽  
Mohammad Alnaief ◽  
...  
Keyword(s):  
Supporting Electrolyte ◽  
Oxygen Demand ◽  
Chemical Vapor ◽  
Electrochemical Reactor ◽  
Olive Mill Wastewater ◽  
Boron Doped Diamond ◽  
Ph Variation ◽  
Bdd Electrode ◽  
Boron Doped ◽  
Olive Mill

A boron doped diamond (BDD) electrode was employed in an electrochemical reactor to oxidize the phenolic content of Jordanian olive mill wastewater. The BDD anode was fabricated using hot filament chemical vapor deposition on niobium and the morphology of the BDD electrode was characterized using an atomic force microscope. Then, electrolysis batch runs were carried out at laboratory scale to test the effect of different process parameters, namely, initial chemical oxygen demand (COD) load (72.9, 33.8, and 0.18 g/L), the addition of Na2SO4 as supporting electrolyte, and adding NaCl along with Na2SO4, on the efficiency of the treatment process. The results were reported in terms of COD, color and turbidity removal, and pH variation. The experiments revealed that electrochemical oxidation using BDD significantly reduced the COD by 85% with no supporting electrolytes. It was observed that adding Na2SO4 with NaCl brought the COD removal to higher than 90% after 7 hours of treatment for COD loads of 72.9 and 33.8 g/L, and after 2 hours for a COD load of 0.18 g/L. Likewise, color was completely removed regardless of the initial COD load. The turbidity for samples with 72.9 and 33.8 g/L as COD load reached a minimal value of 2.5 and 1 NTU respectively.

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