Applicability of electrodialysis to the separation of sodium acetate from synthetic alkaline hardwood extract

TAPPI Journal ◽  
2015 ◽  
Vol 14 (11) ◽  
pp. 695-708 ◽  
Author(s):  
RAVIKANT PATIL ◽  
CHI TRUONG ◽  
JOSEPH GENCO ◽  
HEMANT PENDSE ◽  
ADRIAAN VAN HEININGEN
Keyword(s):  
Current Density ◽  
Sodium Sulfate ◽  
Sodium Acetate ◽  
Separation Efficiency ◽  
Feed Concentration ◽  
Initial Concentration ◽  
White Liquor ◽  
Complete Extraction ◽  
Electro Osmosis ◽  
Preliminary Separation

Our objective was to develop a process for recovering acetyl groups from industrial northeast hardwood chips. Extraction experiments showed that the white liquor charge of 6% effective alkali at 50°C and liquor-to-wood ratio of 4:1 leads to the complete extraction of acetyl groups from industrial hardwood chips. Electrodialysis was assessed as a technique for separating and concentrating sodium acetate from synthetic hardwood extract. Preliminary separation experiments using dilute sodium acetate showed that the sodium acetate can be concentrated up to approximately 24% by weight from an initial concentration of about 2% by weight. The effects of current density, feed concentration, electro-osmosis, and osmosis on the separation of sodium acetate were evaluated. Finally, selectivity experiments were performed to study the effect of various components of the white liquor on the separation of sodium acetate. Fully oxidized synthetic white liquor was used in selectivity experiments to avoid deleterious effects of Na2S. Selectivity experiments using synthetic oxidized white liquor showed a significant decrease in the separation efficiency due to the presence of sodium hydroxide, sodium carbonate, and sodium sulfate in the synthetic extract.

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 hydrocyclone Performance Comparison between Recycled Single Stage and Double Stage Hydrocyclones

2020 ◽  
Vol 21 (3) ◽  
pp. 51-55
Author(s):  
Mohannad A. Raheem ◽  
Raghad F. Qassim
Keyword(s):  
Flow Rate ◽  
Separation Efficiency ◽  
Performance Comparison ◽  
Single Stage ◽  
Feed Concentration ◽  
Modes Of Operation ◽  
Split Ratio ◽  
Inlet Flow Rate ◽  
Water Feed ◽  
The Cost

   This research presents a comparison of performance between recycled single stage and double stage hydrocyclones in separating water from water/kerosene emulsion. The comparison included several factors such as: inlet flow rate (3,5,7,9, and 11 L/min), water feed concentration (5% and 15% by volume), and split ratio (0.1 and 0.9). The comparison extended to include the recycle operation; once and twice recycles. The results showed that increasing flow rate as well as the split ratio enhancing the separation efficiency for the two modes of operation. On the contrary, reducing the feed concentration gave high efficiencies for the modes. The operation with two cycles was more efficient than one cycle. The maximum obtained efficiencies were 97% and 97.5% at 5% concentration, 11 L/min, and 0.9 split ratio for twice recycled single stage and double stage hydrocyclones, respectively. The pressure drop was the same for the two modes of operation. It was concluded that using recycled single stage hydrocyclone was more economical since it reduced the cost of additional hydrocyclone.

Electrochemical Oxidation of Azo Dye Wastewater Using Graphene-Based Electrode Materials

2019 ◽  
Vol 19 (11) ◽  
pp. 7308-7314
Author(s):  
Jinyan Li ◽  
Qingsong Guan ◽  
Junming Hong ◽  
Chang-Tang Chang
Keyword(s):  
Electrochemical Oxidation ◽  
Current Density ◽  
Electrode Materials ◽  
Supporting Electrolyte ◽  
Performance Comparison ◽  
Carbon Cloth ◽  
Reactive Black 5 ◽  
Dye Wastewater ◽  
Composite Electrodes ◽  
Initial Concentration

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.

Electrochemical Degradation of RDX in Aqueous Solution at Constructed Sb-Doped SnO2 Anode

2011 ◽  
Vol 396-398 ◽  
pp. 1803-1806
Author(s):  
Yong Chen ◽  
Lei Hong ◽  
Wei Shi ◽  
Wei Qing Han ◽  
Lian Jun Wang
Keyword(s):  
Aqueous Solution ◽  
Current Density ◽  
Order Reaction ◽  
Electrochemical Degradation ◽  
Kinetics Analysis ◽  
Pseudo First Order Reaction ◽  
Initial Concentration ◽  
First Order ◽  
Sno2 Electrode ◽  
Pseudo First Order

The constructed Sb-doped SnO2 electrode was obtained for electrochemical degradation of RDX. The influences of current density and initial concentration of RDX on electrochemical degradation of RDX were studied. Kinetics analysis shows that the electrochemical degradation of RDX follows the pseudo first-order reaction. The mechanism of electrochemical degradation of RDX was also discussed.

scholarly journals Study of the process of cyanide leaching of gold using sodium acetate at different ore sizes

2020 ◽  
Vol 1 (312) ◽  
pp. 59-68
Author(s):  
Ye. K. Yessengarayev ◽  
◽  
B.S. Baimbetov ◽  
S. V. Mamyachenkov ◽  
B. N. Surimbayev ◽  
...  
Keyword(s):  
Sodium Acetate ◽  
Gold Recovery ◽  
Metal Extraction ◽  
Cyanide Leaching ◽  
Electron Probe Analysis ◽  
Granulometric Analysis ◽  
Complete Extraction ◽  
Crushed Ore ◽  
Kinetics Of ◽  
Technical Measures

Intensification of metal extraction by leaching is a complex of organizational and technical measures aimed at achieving the fastest and complete extraction of metal from ore. Measures to intensify leaching are aimed at completely or partially neutralizing the causes that cause a decrease in the leaching rate. Tests were performed on cyanide leaching of gold from gold-containing ore with the addition of sodium acetate to intensify the leaching process. The results of assay-gravimetric, chemical, mineralogical and granulometric analysis of oxidized ore are presented. According to electron-probe analysis, gold in the ore is present in the form of thin (micron) inclusions in minerals and ore rocks. A study was conducted on leaching of crushed ore with a size of 90% of the class -0.074 mm and crushed ore with a size of -12+0 mm. Leaching of crushed ore with a size of 90% of the class -0.074 mm showed that when adding sodium acetate, the gold recovery rate increases by 1.13 % compared to leaching without adding this reagent. When leaching crushed ore with a size of -12 + 0 mm with the addition of acetate, gold recovery increases by an average of 4 %, and the kinetics of gold dissolution improves. Research data prove that sodium acetate can be used to intensify gold at a ore size of -12+0 mm and in larger ore classes for leaching gold.

scholarly journals Treating kraft mill extract using bipolar membrane electrodialysis for the production of acetic acid

TAPPI Journal ◽  
2016 ◽  
Vol 15 (3) ◽  
pp. 215-226 ◽  
Author(s):  
RAVIKAT PATIL ◽  
JOSEPH GENCO ◽  
HEMANT PENDSE ◽  
ADRIAAN VAN HEININGEN
Keyword(s):  
Acetic Acid ◽  
Energy Consumption ◽  
Sodium Hydroxide ◽  
Current Density ◽  
Salt Solution ◽  
Sodium Acetate ◽  
Process Conditions ◽  
Sodium Acetate Solution ◽  
Bipolar Membrane ◽  
Bipolar Membrane Electrodialysis

The objective of this work was to determine the process conditions for converting sodium acetate, the major component of alkaline hardwood extract, into acetic acid and sodium hydroxide using bipolar membrane electrodialysis (BPMED). The effects of current density and sodium acetate concentration in the feed-salt solution were evaluated using synthetic sodium acetate solution in a feed and bleed mode. This mode of operation represents semibatch processing and was useful for determining the current efficiencies, energy consumption, and other system parameters for the production of about 160 g/L of acetic acid; maximum achievable concentration of acetic acid in electrodialysis; and 30 g/L of sodium hydroxide, which is the concentration sufficient for the extraction of sodium acetate from hardwood. The feed and bleed mode experiments performed at 60 mA/cm2 using 130 and 85 g/L sodium acetate as feed-salt solutions produced similar results, except for a small change in the amount of water transported into the acid and base compartments. The feed and bleed mode experiment performed at low current density of 40 mA/cm2 using 50 g/L sodium acetate as feed-salt solution produced almost similar quantities of acetic acid and sodium hydroxide as those in the other feed and bleed mode experiments. However, the energy consumption and current efficiencies were lower than those for the experiments performed at the current density of 60 mA/cm2.

Effects of added materials on black liquor combustion

TAPPI Journal ◽  
2016 ◽  
Vol 15 (7) ◽  
pp. 479-486
Author(s):  
LIMING ZHAO ◽  
DANIELLY CORTES ◽  
HONGHI TRAN
Keyword(s):  
Systematic Study ◽  
Sodium Sulfate ◽  
Kraft Pulp ◽  
Black Liquor ◽  
The Other ◽  
Pulp Mills ◽  
Combustion Behavior ◽  
White Liquor ◽  
Other Hand ◽  
Kraft Pulp Mills

Black liquor is often mixed with various types of materials before being burned in a recovery boiler to meet specific needs of kraft pulp mills. A systematic study was conducted using a thermogravimetric combustor to examine how added materials might affect the combustion behavior of black liquors obtained from several pulp mills. The results show that adding soap, caustic, white liquor, and sawdust significantly reduces the liquor swelling tendency, thereby requiring a longer time for the liquor to burn completely. Adding makeup saltcake, precipitator ash, sodium sulfate, and biosludge, on the other hand, has little or no effect on the liquor combustion behavior.

Current Density Contour Map of TiNi Shape Memory Alloy in Sulfate Solutions

2007 ◽  
Vol 342-343 ◽  
pp. 569-572
Author(s):  
Seung Chan Na ◽  
Seung Ho Park ◽  
Woon Suk Hwang
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Current Density ◽  
Sodium Sulfate ◽  
Chloride Ion ◽  
Localized Corrosion ◽  
Tini Alloy ◽  
Contour Map ◽  
Sulfate Solutions ◽  
Density Contour

In this study, a current density contour map of TiNi shape memory alloy in sodium sulfate solutions was constructed by potentiodynamic polarization technique. The current density contour map of TiNi alloy, constructed in a 0.5 M sodium sulfate solution over the pH range 1 to 13 at 37oC, showed only hydrogen evolution region, passive region, and oxygen evolution region. The localized corrosion region did not exist and the susceptibility of localized corrosion was not exhibited. We also investigated the effects of chloride ions on the pitting corrosion of TiNi alloy in sodium sulfate solutions. Pitting corrosion occurred with addition of 0.2 M NaCl in a sulfate solution. And it was observed that pitting potential got lower as the concentration of chloride ion went up. However, repassivation potential was not affected by the addition of chloride ion up to 0.5 M. It is concluded that a TiNi shape memory alloy exists as a passive state and a good corrosion resistance in sulfate solutions over the pH range 1 to 13, and the sulfate ion performs a role of inhibiting localized corrosion in chloride environment.

scholarly journals Demulsification of crude oil emulsion via electrocoagulation method

2018 ◽  
Vol 3 (1) ◽  
pp. 97-105
Author(s):  
Firdos. M. Abdulla ◽  
N.H. Abdurahman
Keyword(s):  
Crude Oil ◽  
Current Density ◽  
Performance Test ◽  
Separation Efficiency ◽  
Water Separation ◽  
Oil Emulsion ◽  
Stability Performance ◽  
Nacl Concentration ◽  
Oil Emulsions ◽  
Production Losses

During oil production and processing emulsions were formed and seriously cause problem, both in terms of chemicals used and production losses. The traditional methods of breaking crude oil emulsions are disadvantageous from both economic and environmental perspectives. In this paper, the potentials of electrocoagulation technology in demulsification of crude oil emulsion were investigated. The crude oil obtained from Petronas Ponapean Melaka, Malaysia. For stability performance test, Span 80 was used as emulsifier, while for chemical demulsification performance test,Hexylamine was used. The electrocoagulation method was used for demulsification of W/O emulsion. For electrocoagulation demulsification, three factors namely; voltages 15-50 V, current density 1.04-3.94 mAcm-2, and concentration of NaCl 0.5-2.5 g/L. The electrocoagulation demulsification showed that the best water separation efficiency was achieved at voltage 50 V, current density 3.94 mAcm-2, and NaCl concentration 2.5 g/L, whereas the separation efficiency reached at 98%. Results have shown the potential of electrocoagulation method in separation of water-in-crude oil emulsions, W/O.

scholarly journals Removal of Cr 3+ by electrocoagulation from simulated wastewater

2014 ◽  
Vol 15 ◽  
pp. 89-93 ◽  
Author(s):  
R Ulambayar ◽  
J Oyuntsetseg ◽  
A Tsiiregzen ◽  
D Bayaraa
Keyword(s):  
Aqueous Solution ◽  
Current Density ◽  
Operating Cost ◽  
Operating Time ◽  
Solution Ph ◽  
Chemical Substances ◽  
Initial Concentration ◽  
Electrocoagulation Process ◽  
Simulated Wastewater ◽  
Maximum Removal

Trivalent chromium (Cr3+) removal from aqueous solution  by electrocoagulation using iron electrodes material was investigated in this paper. Effects of current density, initial concentration of Cr 3+, operating time,  pH, electrode distance, and operating cost have been investigated. At higher current density and solution pH, remarkable removal of Cr3+ was observed. Experiments have been show that the maximum removal percentage of the Cr3+ 99.89 % was at initial concentration 1000mg/L,  current density 9.34mA/cm2 and reaction time 1 hours. Energy consumption was calculated  for Cr3+ removal at different time. The method is observed to be very effective in the removal Cr3+ ion from aqueous solution. Electrocoagulation process need simple equipment, designable any size, use any chemical substances and low operating cost.DOI: http://doi.dx.org/10.5564/mjc.v15i0.330 Mongolian Journal of Chemistry 15 (41), 2014, p89-93

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