Preparation Of A Innovative Mixed Matrix Polyethersulfone Membranes By Inserting Graphene Oxide Nanosheets For Wastewater Purification Essay

This further led me, in my junior summer, to a mentorship program with Professor Jaehong Kim at Yale, during which I learned about various materials used for sustainable water treatment, such as fullerenes, carbon nanotubes, and nano-sized membranes. By the end of the summer, I was able to design my own “super-nanomaterial.” but I would have to wait until college to synthesize

In general, membrane treatment processes use either pressure-driven or electrical-driven technologies. Pressure-driven membrane technologies include reverse osmosis (RO), nano-filtration (NF), ultrafiltration

Point-of-use water filters are utilized to remove contaminates immediately before direct consumption for secondary exposure through cooking and cleaning. The media for these filters are chosen because they have good permeability, durable, free of impurities and are insoluble in the water they are filtering [18]. While filter media normally rely mechanical removal of particles, some medium works to also remove contaminates by participating in redox reactions. Other forms of removal include absorption and adsorption. Absorption is the where contaminates and liquid are soaked up like a sponge into the media. Adsorption, the adhesion of a thin layer of particles to the filtration solid, of the silver forms may take for the activated carbon and

They recommend using alternatives such as Ozone and UV. The Ozone is produced artificially using UV light where the oxygen molecule absorbs the UV and breaks it down to 2 oxygen atoms (Lenntech, 2011). This then reacts with another O2 molecule to form the ozone (RMI, 2009). When purifying water dry oxygen/air is passed through high voltage electrodes (Refer to diagram 1). UV lamps are non-chemical disinfectants that kill microorganisms, using UV energy frequencies (ESP , 2015). They destroy the germs by changing their molecular DNA (VAN ISLE WATER, 2013). This method is currently used in regional SA water treatments (SAWater,

Unfortunately, there are some limitations in this method, as its irregular flow distributuion, non-identical membrane size distribution, variable membrane thickness, the availability of appropriate scale-down devices and low binding capacities. Low biding capacity is attribuited to low surface area as well as poor flow

The process of desalination can be described as any process that removes salts and other mineral particles present in a salt water environment from water. Desalination processes can help variety of industries as well as human consumption. In the very beginning desalination processes were associated with much higher costs but since the massive researched and improvements in the technology started happening, desalination processes started competing with less expensive methods for cleanliness of water (Krishna, 1). Two distinct techniques for water treatment processes use either electrical-driven or pressure-driven technologies. For the purpose of this technical report the main focus will revolve around pressure-driven membrane operation which will encompass four overlapping membrane types. These categories compiled of Reverse Osmosis, Nanofiltration, Ultrafiltration and Microfiltration (Pangarkar, Sane, Guddad, 2011).

Graphene is pure carbon in the form of a very thin, nearly transparent sheet, one at6om thick. It has been hailed as a miracle material because of its low weight, high strength and high electrical and heat conductivity. Since 2004, the graphene market has risen and with the potential for future application could be a multibillion dollar business. Graphene has been planned to replace conductors and also replace catalysts in enzyme immobilisation. Graphene can be manufactured in ways that are low-cost and high-return.

Polymer membranes are gaining an ever growing attention in the engineering and science disciplines [P.D.Chapman, T.Oliveira, A.G.Livingston, K.Li, Membranes for the dehydration of solvents by pervaporation, J.Membr.Sci.318 (2008)5–37.]. They have been conventionally used for size exclusion applications for instance micro-filtration (MF),ultrafiltration (UF),nanofiltration (NF),and reverse osmosis (RO). Membranes are used as support matrices for immobilization in the fields of biosensors and enzyme based bioreactors [K. Gabrovska, J.Ivanov, I.Vasileva, N.Dimova, T.Godjevargova, Immobilization of urease on nanostructured polymer membrane and preparation of urea amperometric biosensor, Int.J.Biol.Macromol. 48(2011)620–626.]. Furthermore, affinity and ion-exchange chromatography with functionalized membranes is increasingly applied in the pharmaceutical and biotechnology industry [P.Ghosh, K.Vahedipour, M.Lin, J.H.Vogel, C.A.Haynes, E.vonLieres, Zonal rate model for axial and radial flow membrane chromatography. PartI: Knowledge transfer across operating conditions and scales, Biotechnol. Bioeng. 110(2013)1129–1141.].

Besides the modified MOF for supercapacitor, I also developed self-assembly MOF layer with controllable number of layers for lithium ion batteries. Different with organic solution on which molecules self-assemble together to form a single layer, single layer MOF was assembled on glassy carbon by controlling system pressure. When the pressure was a little lower than atmospheric pressure, MOF began to ‘escape’ from solution and assembled a single layer on glassy carbon substrate. Multilayer MOF film could be achieved easily by repeating this process with desired times. The multiple nanopores in MOF provided excellent ion transportation channels and storage sites and showed strong potential for lithium ions batteries. What’s more, my interest in materials grow stronger and I was motivated to pursue this beautiful, interesting and important research field, nanomaterials and their applications, as my career goals.

In 1899 ionic conductivity was observed in a solution of ZrO2(Y2O3) however the potential for use in oxygen separation technology has only gained attention in the last 35 years. The best oxygen separation capabilities are seen in defect free ceramic membranes and result in 100% pure oxygen. There are a number of different structures that ceramic membranes can take fluorite, perovskite, pyrochlore, brownmillerite and some others. The main two are the fluorite and perovskite type, which will be discussed in further detail later in this report. Oxygen flux is the rate the oxygen transfers though the membrane and a higher oxygen flux means a better membrane. Generally a dense ceramic membrane with a perovskite structure at temperatures greater

(ii) The new and successful application of the single step in-situ deposition of DA to immobilize the GO nanosheets onto the membrane surface was achieved. Applying GO nanosheets with the proper concentration rendered them tightly bound to the membrane surface without aggregations. This optimum modification also improved the membrane surface morphology, smoothness, hydrophilicity and antibacterial properties, resulting in improved desalination performance and better biofouling resistance. This simple and stable surface modification has great potential in the improvement of FO membranes.

Many of today’s water reuse systems use an ultrafiltration (UF) pretreatment step to remove suspended solids.  These systems typically use hollow fiber UF membranes, which do an excellent job of providing water with low suspended solids to feed the RO system.  However, the UF system is an extra treatment step, requiring additional footprint, and adding to operating costs. The UF system may also be susceptible to upsets from a conventional WWTP, which can further increase its operating costs.

One method is to combine catalyst layer and gas diffusion layer that forms an electrode. Another is coating layer which is referred as catalyst coated membranes. The CCM is stuffed between 2 GDL’s. A MEA made of electrode and a polymer membrane has five Layer configuration and it’s known as five layer MEA. It can be installed as an integrated component. The CCM which is 3-layer can be used as an attachment for the GDL’s 5-layer configuration for installation. Carbon micro-porous layer is used for this application. When a fuel and oxidant are applied on anode and cathode side of the catalysts the electrochemical reactions is conducted. Membrane electrode assemblies is typically based on manufacturing and quality control. They have developed a useful product which is not matched by others, and which gives customer satisfaction which they had expected.

Electrospinning generates interconnected, nonwoven 3D porous mats with high porosity and high surface area which can mimic

Water is pure substance while its bond strength between hydrogen and oxygen is extremely strong. In addition, water is very important for both human beings and creatures and also it is essential for health, hygiene and the productivity of the world. However, almost all the supply of water in the world must contain organic material, chemicals, minerals and manmade pollutants, which might result in undrinkable or polluted solution. Moreover, the polluted solution contains deadly bacteria and viruses, which might cause some disease. According to American Geoscience Institute (2015), water is a scarce resource, which cannot be recovered after consuming. It states that most of the fresh water that is available for creatures is both contained in soil and rock below the surface. That is, the portable water account for a low percentage of total water in the world. Therefore, water plays an important role in the world, and also creatures cannot live without cleaning water; hence, water treatment becomes an important issue that should be seriously concerned gradually. This essay will explain some major design of water treatment filter in the world and it will firstly focus on a variety types of water treatment filters, demonstrating and suggestion of design parameter for water treatment filter; Next, demonstrating the appropriate design for sustainability; and finally, comparing the difference of water treatment filter between developed and developing countries