scholarly journals Unidirectional ion transport in nanoporous carbon membranes with a hierarchical pore architecture

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lu Chen ◽  
Bin Tu ◽  
Xubin Lu ◽  
Fan Li ◽  
Lei Jiang ◽  
...  
Keyword(s):  
Ion Transport ◽  
Membrane Filtration ◽  
Nanoporous Carbon ◽  
Water Desalination ◽  
Carbon Membrane ◽  
High Concentration ◽  
Energy Barriers ◽  
Ions Transport ◽  
Pore Architecture ◽  
Hierarchical Pore

AbstractThe transport of fluids in channels with diameter of 1-2 nm exhibits many anomalous features due to the interplay of several genuinely interfacial effects. Quasi-unidirectional ion transport, reminiscent of the behavior of membrane pores in biological cells, is one phenomenon that has attracted a lot of attention in recent years, e.g., for realizing diodes for ion-conduction based electronics. Although ion rectification has been demonstrated in many asymmetric artificial nanopores, it always fails in the high-concentration range, and operates in either acidic or alkaline electrolytes but never over the whole pH range. Here we report a hierarchical pore architecture carbon membrane with a pore size gradient from 60 nm to 1.4 nm, which enables high ionic rectification ratios up to 104 in different environments including high concentration neutral (3 M KCl), acidic (1 M HCl), and alkaline (1 M NaOH) electrolytes, resulting from the asymmetric energy barriers for ions transport in two directions. Additionally, light irradiation as an external energy source can reduce the energy barriers to promote ions transport bidirectionally. The anomalous ion transport together with the robust nanoporous carbon structure may find applications in membrane filtration, water desalination, and fuel cell membranes.

Membrane filtration of wastewater effluents for reuse: effluent organic matter rejection and fouling

2001 ◽  
Vol 43 (10) ◽  
pp. 225-232 ◽  
Author(s):  
C. Jarusutthirak ◽  
G. Amy
Keyword(s):  
Organic Matter ◽  
Membrane Filtration ◽  
Treated Wastewater ◽  
High Concentration ◽  
Effluent Organic Matter ◽  
Dead End ◽  
Flux Decline ◽  
Uf Membranes ◽  
Stirred Cell ◽  
Filtration Unit

The reuse of treated wastewater to augment natural drinking water supplies is receiving serious consideration. Treatment of secondary and tertiary effluent by membrane filtration was investigated by assessing nanofiltration (NF) membrane and ultrafiltration (UF) membranes in bench-scale experiments. It was found that secondary and tertiary effluent contained high concentration of effluent organic matter (EfOM), contributing EfOM-related fouling. Flux decline and EfOM rejection tests were evaluated, using a dead-end stirred cell filtration unit. Surface charge and molecular weight cut-off (MWCO) of membranes were significant factors in membrane performance including permeability and EfOM-rejection.

scholarly journals Ion transport through a nanoporous C2N membrane: the effect of electric field and layer number

RSC Advances ◽  
2018 ◽  
Vol 8 (64) ◽  
pp. 36705-36711 ◽  
Author(s):  
You-sheng Yu ◽  
Lu-yi Huang ◽  
Xiang Lu ◽  
Hong-ming Ding
Keyword(s):  
Electric Field ◽  
Ion Transport ◽  
Molecular Dynamic ◽  
Ion Selectivity ◽  
Water Desalination ◽  
Molecular Dynamic Simulations ◽  
Dynamic Simulations ◽  
Layer Number

Using all-atom molecular dynamic simulations, we show that a monolayer C2N membrane possesses higher permeability and excellent ion selectivity, and that multilayer C2N membranes have promising potential for water desalination.

Electrochemical Control of Ion Transport through a Mesoporous Carbon Membrane

Langmuir ◽  
2014 ◽  
Vol 30 (12) ◽  
pp. 3606-3611 ◽  
Author(s):  
Sumedh P. Surwade ◽  
Song-Hai Chai ◽  
Jai-Pil Choi ◽  
Xiqing Wang ◽  
Je Seung Lee ◽  
...  
Keyword(s):  
Ion Transport ◽  
Mesoporous Carbon ◽  
Carbon Membrane ◽  
Electrochemical Control

Long term operation of high concentration powdered activated carbon membrane bio-reactor for advanced water treatment

2004 ◽  
Vol 50 (8) ◽  
pp. 81-87 ◽  
Author(s):  
G.T. Seo ◽  
C.D. Moon ◽  
S.W. Chang ◽  
S.H. Lee
Keyword(s):  
Activated Carbon ◽  
Water Treatment ◽  
Membrane Bioreactor ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Powdered Activated Carbon ◽  
Carbon Membrane ◽  
High Concentration ◽  
Term Operation ◽  
Nakdong River Basin

A pilot scale experiment was conducted to evaluate the performance of a membrane bioreactor filled with high concentration powdered activated carbon. This hybrid system has great potential to substitute for existing GAC or O3/BAC processes in the drinking water treatment train. The system was installed at a water treatment plant located downstream of the Nakdong river basin, Korea. Effluent of rapid sand filter was used as influent of the system which consists of PAC bio-reactor, submerged MF membrane module and air supply facility. PAC concentration of 20 g/L was maintained at the beginning of the experiment and it was increased to 40 g/L. The PAC has not been changed during the operational periods. The membrane was a hollow fiber type with pore sizes of 0.1 and 0.4 µm. It was apparent that the high PAC concentration could prevent membrane fouling. 40 g/L PAC was more effective to reduce the filtration resistance than 20 g/L. At the flux of 0.36 m/d, TMP was maintained less than 40 kPa for about 3 months by intermittent suction type operation (12 min suction/3 min idling). Adsorption was the dominant role to remove DOC at the initial operational period. However the biological effect was gradually increased after around 3 months operation. Constant DOC removal could be maintained at about 40% without any trouble and then a tremendous reduction of DBPs (HAA5 and THM) higher than 85% was achieved. Full nitrification was observed at the controlled influent ammonia nitrogen concentration of 3 and 7 mg/L. pH was an important parameter to keep stable ammonia oxidation. From almost two years of operation, it is clear that the PAC membrane bioreactor is highly applicable for advanced water treatment under the recent situation of more stringent DBPs regulation in Korea.

Poly(Ionic Liquid)-Derived Graphitic Nanoporous Carbon Membrane Enables Superior Supercapacitive Energy Storage

ACS Nano ◽  
2019 ◽  
Vol 13 (9) ◽  
pp. 10261-10271 ◽  
Author(s):  
Weiyi Zhang ◽  
Shen Wei ◽  
Yongneng Wu ◽  
Yong-Lei Wang ◽  
Miao Zhang ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Energy Storage ◽  
Nanoporous Carbon ◽  
Carbon Membrane ◽  
Poly Ionic Liquid

Li-ion transport in a representative ceramic–polymer–plasticizer composite electrolyte: Li7La3Zr2O12–polyethylene oxide–tetraethylene glycol dimethyl ether

2017 ◽  
Vol 5 (35) ◽  
pp. 18457-18463 ◽  
Author(s):  
Jin Zheng ◽  
Heather Dang ◽  
Xuyong Feng ◽  
Po-Hsiu Chien ◽  
Yan-Yan Hu
Keyword(s):  
Ion Transport ◽  
Dimethyl Ether ◽  
Polyethylene Oxide ◽  
Tetraethylene Glycol ◽  
Composite Electrolyte ◽  
Ions Transport ◽  
Glycol Dimethyl Ether ◽  
Li Ion

It is determined with isotope-replacement NMR that Li ions transport via TEGDME-containing phases in a representative composite electrolyte LLZO–PEO–TEGDME.

scholarly journals Mixing State of Submicrometer Sea Spray Particles Enriched by Insoluble Species in Bubble-Bursting Experiments

2014 ◽  
Vol 31 (1) ◽  
pp. 93-104 ◽  
Author(s):  
Ji Yeon Park ◽  
Sungil Lim ◽  
Kihong Park
Keyword(s):  
Organic Matter ◽  
Membrane Filtration ◽  
Volume Fraction ◽  
Silica Particles ◽  
Artificial Seawater ◽  
Sea Spray ◽  
Natural Seawater ◽  
Mixing State ◽  
High Concentration ◽  
Dissolved Salts

Abstract Measurements of size distribution, hygroscopicity, and volatility of submicrometer sea spray particles produced by the bubble busting of artificial and natural seawater were conducted to determine their mixing state and volume fractions of hygroscopic and nonhygroscopic species or volatile and nonvolatile species. The particles sprayed from artificial seawater having insoluble silica particles were found to be an external mixture of two groups of particles having hygroscopic growth factors (HGFs) of 1.33 (an internal mixture of nonhygroscopic silica particles and hygroscopic salt species) and 1.68 (a similar mixture having more salt species) when the mass ratio of insoluble particles to dissolved salts was higher than 2. For sea spray particles from natural seawater, the external mixing was not significantly observed because of a high concentration of dissolved salts. The HGFs of sea spray particles (80–140 nm) from natural seawater were in the range of 1.70–1.76, which were lower than from pure artificial seawater (1.87), and the HGFs had no change before and after membrane filtration of seawater, suggesting that the sea spray particles from natural seawater contained a significant amount of nonhygroscopic dissolved organic matter in addition to hygroscopic salt species. The volume fraction of the nonhygroscopic species ranged from 20% to 29%, and the highest value was observed for seawater samples from the site where strong biological activity occurred, suggesting that biological materials played an important role in the formation of nonhygroscopic organic matter. Volatility measurements also identified the existence of volatile organic species in single particles from natural seawater, with the volume fraction of volatile species evaporated at 100°C being 4%–5%.

scholarly journals Flow-electrode capacitive deionization enables continuous and energy-efficient brine concentration

2020 ◽  
Author(s):  
Matthias Wessling
Keyword(s):  
Energy Demand ◽  
Saline Water ◽  
Ionic Species ◽  
Economic Feasibility ◽  
Water Desalination ◽  
Capacitive Deionization ◽  
High Concentration ◽  
Agricultural Applications ◽  
High Concentrations ◽  
Desalination Technology

Many industrial and agricultural applications require the treatment of water streams containing high concentrations of ionic species for closing material cycles. High concentration factors are often desired, but hard to achieve with established thermal or membrane-based water treatment technologies at low energy consumptions. Capacitive deionization processes are normally assumed as relevant for the treatment of low salinity solutions only. Flowelectrode capacitive deionization (FCDI), on the other hand, is an upcoming electrically driven water desalination technology, which allows the continuous desalination and concentration of saline water streams even at elevated salinities. Ions are adsorbed electrostatically in pumpable carbon flow electrodes, which enable a range of new process designs.In this article, it is shown that continuously operated FCDI systems can be applied for the treatment of salt brines. Concentrations of up to 291.5 g/L NaCl were reached in the concentrate product stream. Based on this, FCDI is a promising technology for brine treatment and salt recovery. Additionally, a reduction of the energy demand by more than 70% is demonstrated by introducing multiple cell pairs into a continuous FCDI system. While the economic feasibility is not investigated here, the results show that FCDI systems may compete with established technologies regarding their energydemand.

Sign in / Sign up

Export Citation Format

Share Document