Ion Transport through a Modified Heterogeneous Bipolar Membrane and Electromembrane Recovery of Sulfuric Acid and Sodium Hydroxide from a Sodium Sulfate Solution

2020 ◽  
Vol 2 (6) ◽  
pp. 391-398
Author(s):  
N. V. Kovalev ◽  
T. V. Karpenko ◽  
N. V. Sheldeshov ◽  
V. I. Zabolotskii
Keyword(s):  
Sulfuric Acid ◽  
Ion Transport ◽  
Sodium Hydroxide ◽  
Sodium Sulfate ◽  
Sulfate Solution ◽  
Sodium Sulfate Solution ◽  
Bipolar Membrane

scholarly journals The Novel Strategy for Increasing the Efficiency and Yield of the Bipolar Membrane Electrodialysis by the Double Conjugate Salts Stress

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 343 ◽  
Author(s):  
Dong Wang ◽  
Wenqiao Meng ◽  
Yunna Lei ◽  
Chunxu Li ◽  
Jiaji Cheng ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Cation Exchange ◽  
Ammonium Sulfate ◽  
Sodium Sulfate ◽  
Sulfate Solution ◽  
Anion Exchange Membrane ◽  
Ammonium Sulfate Solution ◽  
Bipolar Membrane ◽  
Bipolar Membrane Electrodialysis ◽  
Exchange Membrane

To improve sulfuric acid recovery from sodium sulfate wastewater, a lab-scale bipolar membrane electrodialysis (BMED) process was used for the treatment of simulated sodium sulfate wastewater. In order to increase the concentration of sulfuric acid (H2SO4) generated during the process, a certain concentration of ammonium sulfate solution was added into the feed compartment. To study the influencing factors of sulfuric acid yield, we prepared different concentrations of ammonium sulfate solution, different feed solution volumes, and different membrane configurations in this experiment. As it can be seen from the results, when adding 8% (NH4)2SO4 into 15% Na2SO4 under the experimental conditions where the current density was 50 mA/cm2, the concentration of H2SO4 increased from 0.89 to 1.215 mol/L, and the current efficiency and energy consumption could be up to 60.12% and 2.59 kWh/kg, respectively. Furthermore, with the increase of the volume of the feed compartment, the concentration of H2SO4 also increased. At the same time, the configuration also affects the final concentration of the sulfuric acid; in the BP-A-C-BP (“BP” means bipolar membrane, “A” means anion exchange membrane, and “C” means cation exchange membrane; “BP-A-C-BP” means that two bipolar membranes, an anion exchange membrane, and a cation exchange membrane are alternately arranged to form a repeating unit of the membrane stack) configuration, a higher H2SO4 concentration was generated and less energy was consumed. The results show that the addition of the double conjugate salt is an effective method to increase the concentration of acid produced in the BMED process.

scholarly journals Recovery of Acid and Base from Sodium Sulfate Containing Lithium Carbonate Using Bipolar Membrane Electrodialysis

Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 152
Author(s):  
Wenjie Gao ◽  
Qinxiang Fang ◽  
Haiyang Yan ◽  
Xinlai Wei ◽  
Ke Wu
Keyword(s):  
Sulfuric Acid ◽  
Sodium Hydroxide ◽  
Sodium Sulfate ◽  
Lithium Carbonate ◽  
Environmental Benefits ◽  
Raw Material ◽  
Process Conditions ◽  
Bipolar Membrane ◽  
Experimental Conditions ◽  
Bipolar Membrane Electrodialysis

Lithium carbonate is an important chemical raw material that is widely used in many contexts. The preparation of lithium carbonate by acid roasting is limited due to the large amounts of low-value sodium sulfate waste salts that result. In this research, bipolar membrane electrodialysis (BMED) technology was developed to treat waste sodium sulfate containing lithium carbonate for conversion of low-value sodium sulfate into high-value sulfuric acid and sodium hydroxide. Both can be used as raw materials in upstream processes. In order to verify the feasibility of the method, the effects of the feed salt concentration, current density, flow rate, and volume ratio on the desalination performance were determined. The conversion rate of sodium sulfate was close to 100%. The energy consumption obtained under the best experimental conditions was 1.4 kWh·kg−1. The purity of the obtained sulfuric acid and sodium hydroxide products reached 98.32% and 98.23%, respectively. Calculated under the best process conditions, the total process cost of BMED was estimated to be USD 0.705 kg−1 Na2SO4, which is considered low and provides an indication of the potential economic and environmental benefits of using applying this technology.

X-Ray Microtomography of an Astm C109 Mortar Exposed to Sulfate Attack

1994 ◽  
Vol 370 ◽  
Author(s):  
D.P. Bentz ◽  
Nicos. S. Martys ◽  
P. Stutzman ◽  
M. S. Levenson ◽  
E.J. Garboczi ◽  
...  
Keyword(s):  
Cement Paste ◽  
Sodium Sulfate ◽  
Three Dimensional ◽  
Sulfate Solution ◽  
Sulfate Attack ◽  
Sodium Sulfate Solution ◽  
Mortar Sample ◽  
Air Voids ◽  
X Ray ◽  
Dimensional Image

AbstractX-ray microtomography can be used to generate three-dimensional 5123 images of random materials at a resolution of a few micrometers per voxel. This technique has been used to obtain an image of an ASTM C109 mortar sample that had been exposed to a sodium sulfate solution. The three-dimensional image clearly shows sand grains, cement paste, air voids, cracks, and needle-like crystals growing in the air voids. Volume fractions of sand and cement paste determined from the image agree well with the known quantities. Implications for the study of microstructure and proposed uses of X-ray microtomography on cement-based composites are discussed.

Durability of cement mortars incorporating limestone filler exposed to sodium sulfate solution

2014 ◽  
Vol 19 (5) ◽  
pp. 1347-1358 ◽  
Author(s):  
Jaesuk Ryou ◽  
Seungtae Lee ◽  
Daewook Park ◽  
Seongsoo Kim ◽  
Hoseop Jung
Keyword(s):  
Sodium Sulfate ◽  
Sulfate Solution ◽  
Sodium Sulfate Solution ◽  
Limestone Filler ◽  
Cement Mortars

scholarly journals Deterioration Regularity of Sodium Sulfate Solution Attack on Cemented Coal Gangue-Fly Ash Backfill under Drying-Wetting Cycles

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Shaojie Chen ◽  
Zhen Zhang ◽  
Dawei Yin ◽  
Junbiao Ma
Keyword(s):  
Fly Ash ◽  
Sodium Sulfate ◽  
Sulfate Solution ◽  
Coal Gangue ◽  
Salt Crystallization ◽  
Sodium Sulfate Solution ◽  
Sulfate Ion ◽  
Sulfate Ions ◽  
Ion Contents ◽  
The Masses

To research the properties of cemented coal gangue-fly ash backfill (CGFB) exposed to different concentrations of sodium sulfate solutions under drying-wetting cycles, the mass changes, uniaxial compressive strengths, sulfate ion contents at different depths, and microstructures of CGFB samples were measured in this study. The results show that the CGFB samples were damaged by salt crystallization in the dry state and attacked by the expansive products in the wet state. The sulfate ion contents in CGFB samples increased with the sulfate concentrations and drying-wetting cycles and decreased from the surface to the inside of the samples. The damage process of CGFB samples evolved from the surface to the inside. In the early stage of corrosion, sulfate ions adsorbed to the surface of CGFB samples and consumed nonhydrated particles to form acicular ettringite and other products that filled the material pores. For this stage, the driving force of sulfate ions to enter into the CGFB samples was the highest for the samples immersed in 15% sodium sulfate solution, and the masses and strengths increased the fastest. As the drying-wetting cycles continued, the nonhydrated particles inside the samples were nearly completely hydrated, and the samples were constantly damaged by salt crystallization and dissolution. The corrosion ions entered into the samples and consumed portlandite to produce a large amount of prismatic ettringite and aggravated the internal corrosion of CGFB samples. At the fifteenth drying-wetting cycle, the higher the salt concentration of the immersion solution was, the faster the masses and the strengths of CGFB samples decreased. Moreover, the surface spalling and failure of CGFB samples were more severe.

Effect of Stabilizer and Molding Technics in Chemical Engineering on the Stabilization of Sulfate Rich Soil

2012 ◽  
Vol 577 ◽  
pp. 65-68
Author(s):  
Xiao Xuan Deng ◽  
Lei Dai ◽  
Xin Huang
Keyword(s):  
Production Rate ◽  
Sodium Sulfate ◽  
Calcium Silicate ◽  
Chemical Engineering ◽  
Sulfate Solution ◽  
Cementitious Materials ◽  
Sodium Sulfate Solution ◽  
Calcium Silicate Hydrates

In chemical engineering field, ettringite (AFt) formation effect the stabilization of sulfate rich soil mixed with cementitious materials. The different stabilizer compositions and twice molding technics may avoid and repair the destruction caused by AFt with decreasing the production rate of calcium silicate hydrates(C-S-H) and eliminating the void in stabilized soils. The results show that the strength of stabilized 5% sodium sulfate bearing soils, under above methods, are not less than that of the control ones, and the specimens keep steady after soaking in 5% sodium sulfate solution for 12 weeks.

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