scholarly journals Removal of hexavalent chromium from electroplating wastewater by electrocoagulation with iron electrodes

2013 ◽  
Vol 13 (4) ◽  
pp. 412-418 ◽  
Keyword(s):  
Hexavalent Chromium ◽  
Current Density ◽  
Metal Ion ◽  
Removal Rate ◽  
Ion Concentration ◽  
Wastewater Sample ◽  
Electroplating Wastewater ◽  
Iron Electrodes ◽  
Initial Ph ◽  
Electrocoagulation Process

The performance of electrocoagulation using iron electrodes for the removal of hexavalent chromium from synthetic aqueous solutions and actual industrial electroplating wastewater was studied. Parameters affecting the electrocoagulation process, such as initial pH, applied current density, initial metal ion concentration, COD and time of electroprocessing were investigated. The optimum pH was found to be in the range 4-8. Initial chromium concentrations of 200 – 800 mg L-1 did not influence its removal rate. Higher concentrations were reduced significantly in relatively less time than lower concentrations. Increased current density accelerated the electrocoagulation process, however, on cost of higher energy consumption. Results revealed that best removal was achieved at a current density 40 mA cm-2. The electrocoagulation process was successfully applied to the treatment of an electroplating wastewater sample. Its Cr (VI) ion concentration and COD were effectively reduced under the admissible limits in 50 minutes of electroprocessing.

scholarly journals Effect of various parameters in removing Cr and Ni from model wastewater by using electrocoagulation

2013 ◽  
Vol 15 (4) ◽  
pp. 494-503 ◽  
Keyword(s):  
Removal Rate ◽  
Initial Value ◽  
Effective Surface ◽  
Initial Concentration ◽  
Iron Electrodes ◽  
Electrode Combination ◽  
Initial Ph ◽  
Electrocoagulation Process ◽  
Aluminum Electrodes ◽  
A Current

<p>The performance of a laboratory scale electrocoagulation system for the removal of Cr and Ni from model wastewater was studied systematically using iron and aluminum electrodes with an effective surface area of 13.8 cm2 and a distance of 4 cm. The influence of several parameters, such as initial concentration, electrode combination, current supply and initial pH was investigated during electrocoagulation process. The increase in initial concentration favored removal rate, did not affect nickel removal, but restricted chromium removal, thus indicating its required mechanism of reducing hexavalent ion to trivalent. The best removal efficiency, when metals existed separately in treated solutions, was accomplished with the use of iron electrodes for Cr (50%) and with aluminum electrodes for Ni (90%). When metals co-existed, iron electrodes achieved the best result, which was 76% for Cr and 82% for Ni, leaving 30 mg l-1 and 17 mg l-1 of residual concentrations, respectively, after 180 min of treatment. Solutions&rsquo; nominal pH appeared to be optimal, since increasing or decreasing their initial value did not benefit the electrocoagulation process. Chromium and nickel simultaneous removal was best achieved for conditions of 100 mg l-1 initial concentration, pH 5 and a current of 0.8 A.</p>

scholarly journals Pollutant Removal from Wastewater at Different Stages of the Tanning Process by Electrocoagulation

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Alejandra de la Luz-Pedro ◽  
Efraín F. Martínez Prior ◽  
M. H. López-Araiza ◽  
S. Jaime-Ferrer ◽  
A. Estrada-Monje ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Current Density ◽  
Chromium Content ◽  
Removal Rate ◽  
Minimum Energy ◽  
Pollutant Removal ◽  
Tannery Wastewater ◽  
Wastewater Sample ◽  
Initial Ph ◽  
Tanning Process

The removal of chemical oxygen demand (COD), total organic carbon (TOC), turbidity, and chromium content from tannery wastewater at different stages of the process was experimentally investigated using electrocoagulation (EC) with iron and aluminium electrodes. In the EC of the beamhouse wastewater (S1), the effects of initial pH and current density were analyzed and electrical energy consumption was determined. The COD and TOC in the solution were effectively removed, with an initial pH 7.0, using either metallic electrode. With a current density of 28 mA/cm2 for an electrolysis procedure of 60 minutes, the removal efficiency of COD and TOC was 72% and 57% with aluminium electrodes and 69% and 60% with iron electrodes, respectively. The minimum energy consumption for the highest COD and TOC removal was 0.37 and 0.69 kWh/m3 when employing iron or aluminium electrodes, respectively. At the optimal conditions, removal efficiencies close to 100% for turbidity and chromium content for wastewaters S1-beamhouse, S2-tanning, S3-retanning, and S4-a mixture 1 : 1 : 1 (v/v/v) were achieved. Results show that a pseudosecond-order rate equation provides a good correlation for the removal rate of the parameters. Finally, the results indicate that for tannery wastewater, the EC process does not depend noticeably on the electrode material, but that the stage of the tanning process of wastewater sample has the principal effect on treatment efficiency.

scholarly journals Profile of parameters affecting adsorption of Hexavalent Chromium on low-cost adsorbent- The raw baggase

2020 ◽  
pp. 34-49
Author(s):  
Neetu Tewari ◽  
P Vasudevan
Keyword(s):  
Activation Energy ◽  
Hexavalent Chromium ◽  
Metal Ion ◽  
Low Cost ◽  
Ion Concentration ◽  
Initial Ph ◽  
Dose Concentration ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Kinetics Of

The adsorption of Hexavalent chromium [Cr (VI)] from aqueous solution by raw baggase was studied as a function of initial pH, contact time, dose, concentration and temperature. The optimum initial pH for Cr (VI) uptake was 2.0. At the optimal conditions, Cr (VI) uptake was increased as the dose of adsorbent; the initial metal ion concentration and temperature were increased. Adsorption was fast initially and within the first 30 minutes of contact, the adsorption of Cr (VI) on baggase showed a total uptake of 84.4%. The adsorption data fitted well to Langmuir isotherm model. The maximum adsorption of baggase was found to be 9.4 mg/g. The kinetics of the adsorption was found to be pseudo-second-order. Thermodynamic parameters like activation energy, Gibbs free energy change, enthalpy and entropy were also evaluated. The values for activation energy and enthalpy were found to be 13.4 and 10.7 kJ/mol. Adsorption was found to be endothermic.

scholarly journals Optimization of raw acrylic yarn dye wastewater treatment by electrochemical processes: kinetic study and energy consumption

2019 ◽  
Keyword(s):  
Energy Consumption ◽  
Current Density ◽  
Removal Rate ◽  
Kinetic Modelling ◽  
Dye Wastewater ◽  
Colour Removal ◽  
Important Place ◽  
Toc Removal ◽  
Initial Ph ◽  
Electrocoagulation Process

<p>The textile industry has an important place in the environmental pollution due to its heavy water consumption and to the toxic content of dye. Every succeeding day, the water quality is deteriorated because the wastewater containing the dye is supplied to the receiving medium. In this study, The electrocoagulation and electrofenton processes, which produce less waste than the conventional methods and which are less costly, have been investigated for decolourization of acrylic yarn dyeing wastewater. The electrocoagulation process was involved four electrodes parallel connected. To optimize the treatment, response surface methodology (RSM) was applied. The operating independent conditions were selected as the current density (20 -100 A/m2), reaction time (5-25 minutes) and initial pH (pH 4.3-pH 8.3). As a result of optimization by RSM method, the highest Colour, COD and TOC removal were obtained as 96.2%, 43.8% and 40.4 % , respectively. In order to obtain these results, it was necessary to apply a current density of 100 A/m2 to the wastewater which has been set to an initial pH of 7.2 and 20.7 minutes. With the experimental setup installed, high colour removal can be achieved in as little as 15 minutes. Although the colour removal is high, COD removal does not meet discharge standards. Therefore, electrofenton process was applied for enhancing COD and TOC removal and removal rate increased to 70.0% and 61.5%, respectively. In order to study the removal mechanism for acrylic yarn dye wastewater by electrocoagulation process, kinetic modelling was applied. Energy consumption was also assessed.</p>

scholarly journals Ricinus CommunisPericarp Activated Carbon Used as an Adsorbent for the Removal of Ni(II) From Aqueous Solution

2008 ◽  
Vol 5 (4) ◽  
pp. 761-769 ◽  
Author(s):  
S. Madhavakrishnan ◽  
K. Manickavasagam ◽  
K. Rasappan ◽  
P. S. Syed Shabudeen ◽  
R. Venkatesh ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Activated Carbon ◽  
Contact Time ◽  
Metal Ion ◽  
Ricinus Communis ◽  
Ion Concentration ◽  
Batch Mode ◽  
Adsorption Data ◽  
Initial Ph

Activated carbon prepared from Ricinus communis Pericarp was used to remove Ni(II) from aqueous solution by adsorption. Batch mode adsorption experiments are carried out by varying contact time, metal-ion concentration, carbon concentration and pH to assess kinetic and equilibrium parameters. The adsorption data were modeled by using both Langmuir and Freundlich classical adsorption isotherms. The adsorption capacity (Qo) calculated from the Langmuir isotherm was 31.15 mg/g of activated carbon at initial pH of 5.0±0.2 for the particle size 125-250 µm.

scholarly journals Copper and Lead Ions Removal by Electrocoagulation: Process Performance and Implications for Energy Consumption

2021 ◽  
Vol 10 (3) ◽  
pp. 415-424
Author(s):  
Aji Prasetyaningrum ◽  
Dessy Ariyanti ◽  
Widayat Widayat ◽  
Bakti Jos
Keyword(s):  
Heavy Metals ◽  
Energy Consumption ◽  
Removal Efficiency ◽  
Current Density ◽  
High Current Density ◽  
Energy Requirement ◽  
Lead Ions ◽  
Initial Concentration ◽  
Electroplating Wastewater ◽  
Electrocoagulation Process

Electroplating wastewater contains high amount of heavy metals that can cause serious problems to humans and the environment. Therefore, it is necessary to remove heavy metals from electroplating wastewater. The aim of this research was to examine the electrocoagulation (EC) process for removing the copper (Cu) and lead (Pb) ions from wastewater using aluminum electrodes. It also analyzes the removal efficiency and energy requirement rate of the EC method for heavy metals removal from wastewater. Regarding this matter, the operational parameters of the EC process were varied, including time (20−40 min), current density (40−80 A/m2), pH (3−11), and initial concentration of heavy metals. The concentration of heavy metals ions was analyzed using the atomic absorption spectroscopy (AAS) method. The results showed that the concentration of lead and copper ions decreased with the increase in EC time. The current density was observed as a notable parameter. High current density has an effect on increasing energy consumption. On the other hand, the performance of the electrocoagulation process decreased at low pH. The higher initial concentration of heavy metals resulted in higher removal efficiency than the lower concentration. The removal efficiency of copper and lead ions was 89.88% and 98.76%, respectively, at 40 min with electrocoagulation treatment of 80 A/m2 current density and pH 9. At this condition, the specific amounts of dissolved electrodes were 0.2201 kg/m3, and the energy consumption was 21.6 kWh/m3. The kinetic study showed that the removal of the ions follows the first-order model.

scholarly journals Adsorption Study of Cu2+ Ions from Aqueous Solutions by Bael Flowers (Aegle marmelos)

2020 ◽  
Vol 11 (4) ◽  
pp. 11891-11904
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Metal Ion ◽  
Low Cost ◽  
Sem Analysis ◽  
Ion Concentration ◽  
Maximum Adsorption Capacity ◽  
Aegle Marmelos ◽  
Batch Mode ◽  
Initial Ph

In the present study, batch mode adsorption was carried out to investigate the adsorption capacity of dried bael flowers (Aegle marmelos) for the adsorptive removal of Cu(II) ions from aqueous solutions by varying agitation time, initial metal concentration, the dose of adsorbent, temperature, and initial pH of the Cu(II) ion solution. The percentage removal of 98.7% was observed at 50 ppm initial metal ion concentration, 0.5 g/100.00 cm3 adsorbent dosage, within the contact time of 120 minutes at 30 ºC in the pH range of 4 – 7. The sorption processes of Cu(II) ions was best described by pseudo-second-order kinetics. Langmuir isotherm had a good fit with the experimental data with 0.97 of correlation coefficient (R2), and the maximum adsorption capacity obtained was 23.14 mg g-1 at 30 ºC. The results obtained from sorption thermodynamic studies suggested that the adsorption process is exothermic and spontaneous. SEM analysis showed tubular voids on the adsorbent. FTIR studies indicated the presence of functional groups like hydroxyl, –C-O, –C=O, and amide groups in the adsorbent, which can probably involve in metal ion adsorption. Therefore, dried bael flowers can be considered an effective low-cost adsorbent for treating Cu(II) ions.

scholarly journals Removal of the Rhodamine B Dye at Ti/Ru0.3Ti0.7O2 Anode Using Flow Cell System

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Ali Baddouh ◽  
Brahim El Ibrahimi ◽  
Elhassan Amaterz ◽  
M. Mohamed Rguiti ◽  
Lahcen Bazzi ◽  
...  
Keyword(s):  
Current Density ◽  
Rhodamine B ◽  
Removal Rate ◽  
Flow Cell ◽  
Cell System ◽  
Cod Removal ◽  
Color Removal ◽  
Ion Concentration ◽  
Applied Current ◽  
Rhodamine B Dye

The electrochemical oxidation of the Rhodamine B dye (Rh-B) was carried out using dimensionally stable type anode (DSA, Ti/Ru0.3Ti0.7O2). The work was performed using the electrochemical flow cell system. The effect of several operating factors, such as supporting electrolytes, current density, electrolysis time, temperature, and initial concentration of Rh-B dye, were investigated. The UV-visible spectroscopy and chemical oxygen demand (COD) measurements were conducted to monitor the removal and degradation of Rh-B. The best color removal achieved was found to be 98.3% after 10 min applying 3.9 mA·cm−2 as a current density using 0.07 mol·L−1 of NaCl. Meanwhile, the highest COD removal rate (93.0%) was obtained for an applied current density of 3.9 mA·cm−2 as the optimal operating condition after 180 min reaction time, with 2.98 kW h·m−3 as energy consumption. This shows that the best conditions for color removal are not certainly the same as those for the COD removal. The rises in the concentration of NaCl, and applied current increased the Rh-B color removal rate. The decline in Rh-B dye concentration followed pseudo-first-order kinetics. The obtained values of apparent rate constant were increased by increasing chloride ion concentration. It is concluded that the electro-oxidation on DSA electrode using a flow cell is a suitable process for the removal of Rh-B dye in aqueous solutions.

scholarly journals Sorption Efficiency of a New Sorbent towards Cadmium(II): Methylphosphonic Acid Grafted Polystyrene Resin

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Nacer Ferrah ◽  
Omar Abderrahim ◽  
Mohamed Amine Didi ◽  
Didier Villemin
Keyword(s):  
Metal Ion ◽  
Ph Value ◽  
Ion Concentration ◽  
Methylphosphonic Acid ◽  
Order Kinetic ◽  
Elementary Analysis ◽  
Optimum Ph ◽  
Initial Ph ◽  
Pseudo Second Order ◽  
Polystyrene Resin

A new chelating polymeric sorbent has been developed using polystyrene resin grafted with phosphonic acid. After characterization by FTIR and elementary analysis, the new resin has been investigated in liquid-solid extraction of cadmium(II). The results indicated that phosphonic resin could adsorb Cd(II) ion effectively from aqueous solution. The adsorption was strongly dependent on the pH of the medium and the optimum pH value level for better sorption was between 3.2 and 5.2. The influence of other analytical parameters including contact time, amount of resin, metal ion concentration, and the presence of some electrolytes was investigated. The maximum uptake capacity of Cd(II) ions was 37,9 mg·g−1grafted resin at ambient temperature, at an initial pH value of 5.0. The overall adsorption process was best described by pseudo second-order kinetic. When Freundlich and Langmuir isotherms were tested, the latter had a better fit with the experimental data. Furthermore, more than 92% of Cd(II) could be eluted by using 1.0 mol·L−1HCl in one cycle.

scholarly journals Hybrid Process of Electrochemistry with Magnetite Nanoparticles for Treatment of Turbid Water

2019 ◽  
Vol 26 (3) ◽  
pp. 1-6
Author(s):  
Thamer Jasim Mohammed ◽  
Hadeel Atiya Al-Zuheri
Keyword(s):  
Current Density ◽  
Magnetite Nanoparticles ◽  
Perforated Plate ◽  
Operating Conditions ◽  
Turbid Water ◽  
Turbidity Removal ◽  
Commercial Grade ◽  
Magnetite Fe3o4 ◽  
Initial Ph ◽  
Electrocoagulation Process

Magnetic nanoparticles are now being investigated widely in field of water treatment. The aim of this study was to evaluate the feasibility of electrocoagulation process combined with addition of magnetite nanoparticles as a turbidity removal process. Bentonite was used as source of turbidity for the synthetic turbid water. Experiments were conducted in a bench scales electrocoagulation reactor where voltage was applied across a perforated plate of aluminum as anode, and iron mesh as cathode. Commercial grade of magnetite (Fe3O4) with an average nanoparticle size of 50 nm was used. The effect of some factors such as initial pH of the solution (5-9), current density (5-25 mA/cm2), and magnetite dosage (0.4-2.5 gm) on the efficiency of the process were studied. The residual turbidity obtained by using electrocoagulation process alone was (7.47 NTU) from initial turbidity of (200 NU) at constant conditions of pH 6, current density 15 mA/cm2 and electrolysis time 20 min. While under these same conditions the combined electrocoagulation + magnetite process with the added (1.4 gm) of magnetite and under the same operating conditions the residual turbidity was (4.34 NTU), which indicate that the magnetite nanoparticles enhanced the electrocoagulation process.

Sign in / Sign up

Export Citation Format

Share Document