scholarly journals Removal of Cadmium from Simulated Wastewaters Using a Fixed Bed Bio-electrochemical Reactor

2020 ◽  
Vol 26 (12) ◽  
pp. 110-130
Author(s):  
Duaa R. Saad ◽  
Ziad T. Alismaeel ◽  
Ali H. Abbar
Keyword(s):  
Energy Consumption ◽  
Current Efficiency ◽  
Removal Efficiency ◽  
Applied Voltage ◽  
Ph Value ◽  
Fixed Bed ◽  
Cell Voltage ◽  
Packed Bed ◽  
Electrochemical Reactor ◽  
Operating Conditions

In this research, the removal of cadmium (Cd) from simulated wastewater was investigated by using a fixed bed bio-electrochemical reactor. The effects of the main controlling factors on the performance of the removal process such as applied cell voltage, initial Cd concentration, pH of the catholyte, and the mesh number of the cathode were investigated. The results showed that the applied cell voltage had the main impact on the removal efficiency of cadmium where increasing the applied voltage led to higher removal efficiency. Meanwhile increasing the applied voltage was found to be given lower current efficiency and higher energy consumption.  No significant effect of initial Cd concentration on the removal efficiency of cadmium but increasing the initial concentration would be given higher current efficiency and lower energy consumption. The results established that using a pH value lower than three results in a sharp decrease in the removal efficiency as well as  using a pH value higher than seven results in decreasing the removal efficiency. Using a mesh number higher than 30 gave a lower removal efficiency. The best operating conditions were found to be an applied potential of 1.8 V, an initial Cd concentration of 125 ppm, and a pH of 7. Under these operating conditions with the using a stack of stainless with mesh number 30 as a packed bed cathode, a complete removal efficiency of Cd(100%)  was obtained at a current efficiency of 83.57% and energy consumption of 0.57 kWh/kg Cd.

The Pulse Electrolysis Treatment of Waste Emulsion Orthogonal Experimental Study

2013 ◽  
Vol 303-306 ◽  
pp. 2616-2619
Author(s):  
Xiao Yan Sun ◽  
Pei Dao Pan ◽  
Jang Jie Wang
Keyword(s):  
Experimental Study ◽  
Removal Efficiency ◽  
Current Density ◽  
Pulse Width ◽  
Ph Value ◽  
Operating Conditions ◽  
Cod Removal ◽  
Pulse Electrolysis ◽  
Cod Removal Efficiency ◽  
Plate Distance

This mechanical processing waste emulsion for the study, handled by pulse electrolysis. Arrangements by orthogonal testing, experimental study on plate distance (d), current density (i), the pH value and the pulse width (tP) impact on COD removal efficiency, very poor analysis of test data to determine various factors affecting the COD removal efficiency of primary and secondary sort: pH value > current density > pulse width > plate distance, optimal operating conditions. Orthogonal experimental data derived from regression analysis, determination of cross of quadratic polynomial regression equations, mathematical model. Tests confirmed that pulse electrochemical method for treatment of waste emulsion with low energy consumption, short response time, and other advantages, strong applicability of wastewater, building mathematical models, providing theoretical basis for subsequent design.

Metal Instabilities and its Effect on Cell Performance during Aluminium Smelting

2013 ◽  
Vol 828 ◽  
pp. 45-54 ◽  
Author(s):  
Anupam Agnihotri ◽  
Shail Umakant Pathak ◽  
Jyoti Mukhopadhyay
Keyword(s):  
Energy Consumption ◽  
Current Efficiency ◽  
Cell Voltage ◽  
Aluminum Electrolysis ◽  
Cell Performance ◽  
Consumption Pattern ◽  
Magnetic Current ◽  
Zero Current ◽  
Aluminium Smelting ◽  
Rolling Noise

The Hall-Heroult process for the production of aluminium is based on the electrochemical reduction of alumina (Al2O3) dissolved in a cryolite (Na3AlF6) based electrolyte. Instability in cell voltage is referred to as noise. Normal voltage noise is inevitable due to bubble evolution and it has little effect on performance parameters such as, current efficiency and power consumption. Metal rolling noise (wavy noise) is caused by the disturbances in cell magnetic field and it affects the cell current efficiency adversely. Investigating the causes of the cell instability in the aluminium smelting cells can lead to better cell performance. Understanding the variation in cell voltage is critical for cells, because magnitude of voltage determines the energy consumption pattern in the process and hence, any saving on voltage can save energy. Voltage affects the current efficiency of the cell and an optimum cell voltage leads to higher current efficiency without compromising on energy consumption. Magnetic, current distribution, heat loss and voltage at zero current measurements along with online current and voltage signal can help to identify the problems and their combined effects on the performance of the cells. In order to estimate the loss in current efficiency of the aluminum electrolysis cells due to metal instabilities, measurements were performed and data analyzed. The present paper analyses the effect of voltage fluctuations (noise) during metal instability along with cause of instability and its effect on current efficiency of the cell. Measurements carried out to estimate the deviations from the normal cell operations are also discussed.

scholarly journals Electrochemical removal of copper from a simulated wastewater using a rotating tubular packed bed of woven screens electrode

2019 ◽  
Vol 12 (2) ◽  
pp. 127-134
Author(s):  
Jenan Hussein Hemeidan ◽  
Ali H. Abbar
Keyword(s):  
Removal Efficiency ◽  
Process Parameters ◽  
Copper Concentration ◽  
Rotation Speed ◽  
Packed Bed ◽  
Electrochemical Reactor ◽  
Copper Removal ◽  
A Value ◽  
Optimization Of Process Parameters ◽  
Simulated Wastewater

Copper removal from a simulated wastewater was investigated by using rotating tubular packed bed of woven screens electrode as a cathode in a new design of electrochemical reactor. Effects of electrolysis operating parameters like current (0.5–2.5 A), rotation speed (150–750 rpm), and initial copper concentration (100–500ppm) were investigated. Optimization of process parameters was carried out by adopting response surface methodology (RSM) combined with Box–Behnken Design (BBD) where copper removal efficiency was selected as a response function. The results indicated that current has the main effect on the copper removal efficiency followed by rotation speed and concentration. The results of regression analysis revealed that the experimental data could be fitted to a second-order polynomial model with a value of determination coefficient (R2) equal to 0.9894 and Fisher test at value of 51.57 for. The optimum conditions of the process parameters based on RSM method were an initial copper concentration of 205 ppm, current of 2.5A, and rotation speed of 750 rpm utilizing cathode composed of screens with mesh no. 30 where a final copper concentration less than 2 ppm was obtained after 30 min.

scholarly journals Practical study on the electrochemical simultaneous removal of copper and cadmium from simulated wastewater using rotating tubular packed bed cathode

2019 ◽  
Vol 7 (2) ◽  
pp. 90-100
Author(s):  
Jenan Hemeidan ◽  
Ali Abbar
Keyword(s):  
Current Efficiency ◽  
Removal Efficiency ◽  
Rotation Speed ◽  
Total Concentration ◽  
Packed Bed ◽  
Weight Percent ◽  
Simultaneous Removal ◽  
Electrolysis Time ◽  
Initial Stage ◽  
Simulated Wastewater

The simultaneous removal of copper and cadmium from a simulated wastewater using rotating tubular packed bed of woven screens electrode was investigated. The effect of weight present of each metal on the removal efficiency and current efficiency was studied. The experiments were carried out at current 1.5 A, rotation speed 450 rpm, pH=2, and total concentration of metals (300 ppm) at different weight percent of each metal. The results showed that the removal efficiency of copper increased from 93.5 % to 99.33% as its weight percent increased from 20% to100%. In a similar fashion, the removal efficiency of cadmium increased from 80% to 90% as its weight percent increased from 20% to100 %. The results confirmed that the removal efficiency of any metals decreased in the presence of other metal. The results established that current efficiency for the simultaneous removal of copper and cadmium decreased with increasing of electrolysis time and Cd percent weight or decreasing of Cu weight percent. Current efficiency is higher at the initial stage of electrolysis and then declined with increasing time for all weight percent of metals.

Utilisation of Biogas From an Urban Sewage Treatment Plant in a Solid Oxide Fuel Cell

2010 ◽  
Author(s):  
Andrea Lanzini ◽  
Pierluigi Leone ◽  
Massimo Santarelli
Keyword(s):  
Sewage Treatment ◽  
Fixed Bed ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Cell Voltage ◽  
Operating Conditions ◽  
Fixed Bed Reactor ◽  
Urban Sewage ◽  
Anode Degradation ◽  
Anode Supported Cell

A biogas coming from anaerobic digestion of urban sewage has been used to feed a SOFC planar anode-supported cell. The sewage is produced from the urban area of Torino (IT), and eventually collected and treated by SMAT (the municipal company managing the potable and waste water of the city). The biogas is produced by the thermophilic fermentation of the sludge which remains after the several treatments the sewage goes through in the above-mentioned plant. The biogas is of a high quality: it has on average a a methane content around 65% (the balance being essentially CO2), and the only significant impurity measured is H2S in a range of 70–80 ppm. The as-produced biogas has been used for feeding a planar Ni-YSZ anode-supported SOFC with a LSCF cathode. The biogas desulphurization was accomplished flowing the gas in a fixed-bed reactor, filled with activated. The fuel processing with POX has been assessed to avoid carbon deposition into the Ni-YSZ anode and convert the CH4 into H2 and CO. Short tests to check for eventual anode degradation were performed under typical operating conditions. The cell voltage was always stable under load with the tested mixtures. A cell electrical efficiency around 45% has been measured at 800°C and 80% FU. System simulations have performed as well to assess the whole system configuration under a biogas feeding. Optimization routines have been implemented to predict the best net AC efficiency achievable by a SOFC system running on biogas. Additional considerations on the management of poor LHV biogas mixture have been also assessed, showing how dry-reforming of CH4 with the CO2 already available in the biogas stream would be an excellent option needed to be investigated with further detail in the next future.

scholarly journals Simultaneous Removal of Arsenite and Fluoride from Groundwater using Batch Electrochemical Coagulation Process-Role of Aluminum with Iron Electrodes

2019 ◽  
Vol 35 (1) ◽  
pp. 85-97 ◽  
Author(s):  
Shruthi Murthy ◽  
Mahesh Shivaswamy ◽  
Sahana Mahesh ◽  
Srikantha Hanumanthappa
Keyword(s):  
Operating Cost ◽  
Cell Voltage ◽  
Electrochemical Reactor ◽  
Operating Conditions ◽  
Electrode Spacing ◽  
Fluoride Removal ◽  
Special Focus ◽  
Simultaneous Removal ◽  
Initial Value ◽  
Arsenite Removal

Aluminum(Al) and Iron(Fe) electrodes were used forsimultaneous removal of arsenite and fluoride from groundwater using novel electrochemical coagulation (ECC)with special focus on electrode placing positions of Fe and Al in a batch electrochemical reactor (BECR).A series of experiments were carried out to observe the influence of electrode placing positions on removal. Of the many electrode combination, Al1-Al2-Al3-Al4, Fe1-Fe2-Fe3-Fe4, Al1-Al2-Fe3-Al4 and Fe1-Fe2-Al3-Fe4 are discussed in this paper for pre-optimized operating conditions: 4 plate electrodes, As (III)o: 1.6 mg/L, Fo‾: 12 mg/L, Al3+: 0 mg/L, Feo: 0.061 mg/L, inter-electrode spacing: 5mm, applied cell voltage:16V, SA/V ratio: 40 m2/m3 and electrolysis time of 45 min. For the said electrode combinations,the maximum simultaneous removal of both arsenite and fluoride was obtained for Fe1-Fe2-Al3-Fe4 with 97% arsenite removal from its initial value of 1.6 mg/L; and 100% fluoride removal from its initial value of 12 mg/L within 45 min of ET. Energy consumption was 2.01 KWh/m3 with operating cost of 2.90 Rs./m3.

scholarly journals Selective Recovery of Tellurium from the Tellurium-Bearing Sodium Carbonate Slag by Sodium Sulfide Leaching Followed by Cyclone Electrowinning

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1176
Author(s):  
Zhipeng Xu ◽  
Zoujiang Li ◽  
Dong Li ◽  
Xueyi Guo ◽  
Ying Yang ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Current Efficiency ◽  
Sodium Carbonate ◽  
Flow Rate ◽  
Current Density ◽  
Sodium Sulfide ◽  
Cell Voltage ◽  
Promising Alternative ◽  
Selective Recovery ◽  
Solid Ratio

The rigorous environmental requirements promote the development of new processes with short and clean technical routes for recycling tellurium from tellurium-bearing sodium carbonate slag. In this paper, a novel process for selective recovery of tellurium from the sodium carbonate slag by sodium sulfide leaching, followed by cyclone electrowinning, was proposed. 88% of tellurium was selectively extracted in 40 g/L Na2S solution at 50 °C for 60 min with a liquid to solid ratio of 8:1 mL/g, while antimony, lead and bismuth were enriched in the leaching residue. Tellurium in the leach liquor was efficiently electrodeposited by cyclone electrowinning without purification. The effects of current density, temperature and flow rate of the electrolyte on current efficiency, tellurium recovery, cell voltage, energy consumption, surface morphology, and crystallographic orientations were systematically investigated. 91.81% of current efficiency and 95.47% of tellurium recovery were achieved at current density of 80 A/m2, electrolyte temperature of 45 °C and electrolyte flow rate of 400 L/h. The energy consumption was as low as 1.81 kWh/kg. A total of 99.38% purity of compact tellurium deposits were obtained. Therefore, the proposed process may serve as a promising alternative for recovering tellurium from tellurium-bearing sodium carbonate slag.

scholarly journals Efficiency of the electrochemical treatment of textile effluent using two configurations of sacrificial electrodes

2018 ◽  
Vol 18 (1) ◽  
pp. 13
Author(s):  
Leandro Fleck ◽  
Jeysa Piza Santana Passos ◽  
Andrieli Cristina Helmann ◽  
Eduardo Eyng ◽  
Laércio Mantovani Frare ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Electrode Array ◽  
Electrochemical Reactor ◽  
Electrochemical Treatment ◽  
Operating Conditions ◽  
Color Removal ◽  
Textile Effluent ◽  
Parallel Plates ◽  
Cylindrical Electrode ◽  
Efficient Treatment

Textile industries have as main characteristic the generation of effluents with high color, and efficient treatment techniques are necessary. In this context, this study compared the efficiency of the electrochemical treatment for color removal from synthetic textile effluent using two configurations of sacrificial electrodes, parallel plates and array of cylindrical electrodes. For application of the electroflocculation technique, an electrochemical reactor was used, in a laboratory scale, operated in a continuous flow. The synthetic textile effluent was prepared with preset concentrations of reactive dye Blue 5G and sodium chloride. Sacrificial iron (Fe) electrodes with different configurations were used: parallel plates and cylindrical electrodes. The Hydraulic Retention Time (HRT) and electric current density (j) were controlled, and their effects on color removal were evaluated using a Central Composite Rotational Design (CCRD) composed of 12 trials. For the electrochemical treatment using parallel plates, the color removal efficiency ranged from 56.13% to 98.95% and for the electrochemical treatment using an array of cylindrical electrode, the color removal efficiency varied from 2.11% to 97.84%. The mathematical models representative of the process explained a high proportion of the total data variability, with a coefficient of variation of 99.49% and 97.21% for parallel plates and arrangement of cylindrical electrodes, respectively. The electrochemical treatment using parallel plates presents advantages over the configuration using a cylindrical electrode array, since the color removal efficiency is superior under the same operating conditions, representing economic and environmental gains.

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.

scholarly journals Factory Tea Waste Biosorbent for Cu(II) and Zn(II) Removal from Wastewater

2021 ◽  
Vol 287 ◽  
pp. 04006
Author(s):  
Patrick Tan Peng Jun ◽  
Wan Nur Aisyah Wan Osman ◽  
Shafirah Samsuri ◽  
Juniza Md Saad ◽  
Muhamad Fadli Samsudin ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Removal Efficiency ◽  
Metal Ion ◽  
Metal Removal ◽  
Ph Value ◽  
Heavy Metal Removal ◽  
Fixed Bed ◽  
Ion Concentration ◽  
Fixed Bed Adsorption ◽  
Tea Waste

Recent studies have shown great interest toward heavy metal removal due to its hazardous and non-biodegradable properties. Many approaches have been used for this purpose and one of them is adsorption. In this study, several experiments were carried out to investigate the feasibility of factory tea waste as a biosorbent in a fixed-bed adsorption column for heavy metal removal (zinc and copper) in wastewater. The results highlighted that zinc has better performance compared to copper in terms of the effect of initial ion concentration, pH value, and the mixed ions with respect to the removal efficiency. Zinc showed higher removal efficiency and adsorption capacity at the initial metal ion concentration of 200 mg/L, which are 99.21% and 39.68 mg/mg compared to copper. Meanwhile, for the effect of pH values and mixed ion concentration, zinc also showed slightly higher removal efficiency which are 99.91% and 98.47%, respectively compared to copper. However, both zinc and copper showed a better fit to the Langmuir isotherm. The factory tea waste was characterized using Micromeritics ASAP 2020 instrument and results showed that the factory tea waste biosorbent consists of mesopores with the diameter and width of 4.85205 and 2.546985 nm, respectively.

Sign in / Sign up

Export Citation Format

Share Document