Solvothermal synthesis of high-performance Ni-Co layered double hydroxide nanofoam electrode for electrochemical energy storage

라즈쿠마파텔,Akbar I. Inamdar,Bo Hou,차승남,Abu Talha Ansari,Jayavant L. Gunjakar,임현식,김형상 한국물리학회 2017 Current Applied Physics Vol.17 No.4

A nanofoam nickel cobalt layered double hydroxide (NiCo(OH)2) electrode film is fabricated on a stainless-steel substrate with the use of a simple one-step solvothermal process. The nanofoam NiCo( OH)2 electrode exhibits a high specific capacitance of 2710.2 F/g at a current density of 9.1 A/g, and a good capacity retention of ~70% after 2000 charge-discharge cycles at a high current density of 31.8 A/g. An energy density of 60.23 Wh/kg is obtained at a power density of 1.8 kW/kg. The excellent electrochemical energy storage performance of the NiCo(OH)2 electrode is due to the synergetic effect of a significantly improved ionic diffusion and an effective charge transfer, which is linked to a well-dispersed interconnected nanofoam morphology and binder-free direct contact with the current collector.

Membrane Containing Biocidal Material for Reduced Biofilm Formation: A Review

라즈쿠마파텔,손수현 한국막학회 2022 멤브레인 Vol.32 No.1

Bacteria grow biofilm on various surface such as separation membrane, food packaging film and biomedical device. Growth of biofilm is associated with the formation of a complex structure of exopolysaccharides. Effect of anti- bacterial effect reduce drastically once the biofilm developed due to the difficulties in mass transport of antimicrobial agent. In order to enhance the antibacterial activity, surface of the membrane is modified, coated or immobilized with functional materials with biocidal properties. One of the idea is to introduce positive charge on the membrane surface by the presence of quaternary ammonium group which might displace divalent metal ion such as magnesium or calcium present in the bac- teria cell wall. Efficacy of cell membrane disruption depends on the mobility of the agents available directly on the surface environment. In this review, various biocidal agents like quaternary ammonium group, helamine or zwitter ion containing membrane are discussed.

Recovery of Valuable Minerals from Sea Water by Membrane Separation and Adsorption Process: A Review

라즈쿠마파텔,전성수 한국막학회 2022 멤브레인 Vol.32 No.1

Ever increasing global energy demand gives rise to uncontrollable environmental pollution. Demand on fossil fuel and consequent carbon emission leads to global warming and climate change. Nuclear energy is an alternative source to generate clean energy but mining of nuclear fuel is associated with harmful chemicals. Mining of valuable minerals from sea water by membrane separation process is a cost effective along with environmental friendly process. Separation and ad- sorption based mining of valuable minerals from sea water are another efficient process. Recovery of actinides from rare earth elements are very challenging and expensive process. Pressure driven membrane separation process is economically more viable along with environmental process. In this review membrane separation process are based on polyether sulfone, polyamide, polyimide, polyamidoxine and hybrid membranes. In case of adsorption process, mainly amidoxime kind of ad- sorbent are discussed.

Enzyme Immobilized Membrane Bioreactor for Removal of Dye: A Review

라즈쿠마파텔,유한정 한국막학회 2023 멤브레인 Vol.33 No.6

Enzyme Immobilized Membrane Bioreactors (EMBRs) are a novel method to treat dyes within wastewater. Due to their efficacy and high resistance to the environment, there has been a large amount of research being done in thisarea. There are a variety of ways to approach EMBRs that include both the enzyme itself and the structure of said enzymes. The bioreactor itself can be modified to suit the needs of the dye removal. Ranging from Enzymatic bioreactors to utilizingnanostructures such as graphene oxide or carbon nanotubes. Furthermore, nanoparticles such as TiO2 can be used to enhancethe EMBR further as well. The polymer-based membrane supporting structure also includes a variety of different ways toapproach the problem of increasing efficacy. As seen, during the past decades, different approaches to this issue that utilizeEMBRs have been done. This review aims to summarize the methodologies and describe the various improvements toEMBRs that have been made.

Ceramic Based Photocatalytic Membrane for Wastewater Treatment: A Review

라즈쿠마파텔,곽연수 한국막학회 2022 멤브레인 Vol.32 No.3

Membrane separation provides various advantages including cost effectiveness and high efficiency over tradi- tional wastewater treatment methods such as flocculation and adsorption. However, the effectiveness of membrane separation greatly declines due to membrane fouling, where pollutants are accumulated on the membrane surface. Among different groups of membranes, ceramic membranes can provide good antifouling properties due to its hydrophilicity and chemical stability. In addition, composite membranes such as graphene oxide modified membranes can help prevent membrane fouling. Recently, hybrid photocatalytic membranes have been proposed as a solution to prevent membrane fouling and pro- vide synergetic effects. Membrane separation can solve the disadvantages of photocatalytic oxidation such as low reutiliza- tion rate, while photocatalytic oxidation can help reduce membrane fouling.

Zeolite Based Membrane for Removal of Ammonium: A Review

라즈쿠마파텔,이주엽 한국막학회 2022 멤브레인 Vol.32 No.3

Presence of ammonia in drinking water is very toxic to human health. Soluble ammonia contaminates ground water due to activities such as the use of fertilizer in crop, industrial effluents and burning of fossil fuel. Even low concen- tration of ammonia present in water will damage aqua environment such as marine organism. Membrane technology is an important process to remove ammonia from effectively from water. Flat sheet membrane, membrane contactor and mem- brane distillation are some of the methods used for water purification from ammonia. Membrane contractor is an efficient process in which ammonia is removed through liquid-gas or liquid-liquid mass transfer without change of phase unlike membrane distillation. However, the cost of ammonia removal in this method is high due to maintenance of very high pH. Zeolite has excellent ion exchange ability that enhances its ability to interact with ammonia and adsorb from wastewater. Mixed matrix membranes containing zeolite enhance the efficiency of ammonia adsorption and separation from wastewater. In this review the above discussed issues are summarized in detail.

Alkali Recovery by Electrodialysis Process: A Review

라즈쿠마파텔,살센벡 아샐 한국막학회 2023 멤브레인 Vol.33 No.3

Electrodialysis (ED) is essential in separating ions through an ion exchange membrane. The disposal of brine generated from seawater desalination is a primary environmental concern, and its recycling through membrane separation technology is highly efficient. Alkali is produced by several chemical industries such as leather, electroplating, dyeing, and smelting, etc. A high concentration of alkali in the waste needs treatment before releasing into the environment as it is highly corrosive and has a chemical oxygen demand (COD) value. The concentration of calcium and magnesium is almost double in brine and is the perfect candidate for carbon dioxide adsorption, a major environmental pollutant. Sodium hydroxide is essential for the metal carbonation process which, is easily produced by the bipolar membrane electrodialysis process. Various strategies are available for its recovery, like reverse osmosis (RO), nanofiltration (NF), ultrafiltration (UF), and ED. This review discusses the ED process by ion exchange membrane for alkali recovery are discussed.

A Review on Ceramic Based Membranes for Textile Wastewater Treatment

라즈쿠마파텔,곽연수 한국막학회 2022 멤브레인 Vol.32 No.2

Among various industries, the textile industry uses the largest amount of water for coloring textiles which leads to a large amount of wastewater containing various kinds of dye. There are various methods for the removal of dye such as flocculation, ozone treatment, adsorption, etc. But these processes are not much successful due to the issue of re- cycling which enhances the cost. Alternatively, the membrane separation process for the treatment of dye in wastewater is already documented as the best available technique. Polymeric membrane and ceramic membrane are two separate groups of separation membranes. Advantages of ceramic membranes include the ease of cleaning, long lifetime, good chemical and thermal resistance, and mechanical stability. Ceramic membranes can be prepared from various sources and natural materials like clay, zeolite, and fly ash are very cheap and easily available. In this review separation of wastewater is classified into mainly three groups: ultrafiltration (UF), microfiltration (MF), and nanofiltration (NF) process.

Recent Progress in Zeolite Membrane for Wastewater Treatment: A Review

라즈쿠마파텔,이주엽 한국막학회 2022 멤브레인 Vol.32 No.4

Wastewater is released from leather, textile, paint, wood, or dye processing industries as well as petroleum refining industries. Wastewater from these industries contains water pollutant such as heavy metals and nitrogen compounds and has high chemical oxygen demand (COD). While there various filtering pollutants from wastewater for safe disposal, membrane-based technology is one of the most efficient methods for its high efficiency and low cost. Among various membranes, zeolite membranes gain spotlight for its cost-effectiveness and have undergone a lot of research. This review is focused on recent progress in zeolite membrane for wastewater treatment in following order: i) wastewater treatment, ii) microfiltration membrane, iii) hollow fiber membrane, and iv) ultrafiltration membrane.

Recovery of Valuable Lithium Hydroxide by Ion Exchange Process: A Review

라즈쿠마파텔,살센벡 아샐 한국막학회 2022 멤브레인 Vol.32 No.6

Demand for lithium hydroxide (LiOH) is annually increasing due to its efficiency and safety for the environment in comparison to its current alternatives. Lithium can be found in different salty and brine lakes which later synthesized to produce LiOH for various applications. Different methods are used to separate and recover lithium ions, the most common of which is electrodialysis (ED). ED is a membrane-based separation technique which works on potential difference of its layers as a driving force to push ions from one side to another. The ion exchange membrane (IEM) in ED makes the process efficient because of the perm selectivity of different ions vary depending on their hydrodynamic volume. In this review, the different alteration strategies of both ED and IEM, to enhance the recovery of lithium ions are discussed.