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

Water contamination is vastly becoming an alarming issue across the world. We rely on clean water to survive, yet right now we are heading towards a water crisis. Changing climate patterns are threatening lakes and rivers, and key sources that we tap for drinking water are being overdrawn or tainted with pollution (www.nrdc.org). Clean and plentiful water is the cornerstone of prosperous communities. Yet as we enter the 21st century, swelling demand and changing climate patterns are

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

There is a water crisis which faces many parts of the world and it is a threat to survival of human beings since humans are primarily dependent on water. Shortage in drinking water is beginning to show its effects in first world countries, but is a current major problem facing lesser developed countries which have not taken drastic steps to harvest water and purify it to make it safe for human consumption. In developed countries the population growth has strained available water resources and stretched the ability of governments and private firms to provide safe drinking water to the vast majority of the population. Seventy one percent of

All around the world, countries are fighting to keep their drinking water clean. Whether it’s streams, rivers, or lakes, countries have taken great measures to maintain high quality drinking water for both human consumption and animal consumption. Countries must first understand the sources of the polltion, then determine the best methods to eliminate the pollution. Clean drinking water is a valuable resource and a the key to human survival. Plants and animals also depend on water for their growth, so all water must be kept clean. The major contributors to water pollution can be classified in three categories, industrial, agricultural and municipal.

(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.

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

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

The research on graphene scaffold for wound dressing and cell culture is a relatively new direction that deserves special attention. Enormous studies in this field so far demonstrated that graphene is antibacterial (Akhavan et al, 2010), accelerate the growth (Kalbacova et al, 2010), differentiation (Nayak et al, 2011), and proliferation of mammalian cells (Ryoo et al, 2010), and hence hold great potential in tissue engineering, regenerative medicine and other biomedical fields. Graphene is selected as an effective nanocarrier due to its potential for crossing the plasma membrane and promoting the cellular uptake of pathogen at infected site. Andre Geim and Konstantin Novoselov were awarded the Nobel Prize for their meticulous work in 2010 “for ground breaking experiments regarding the two-dimensional material graphene” as monocrystalline graphitic films (Novoselov et al, 2004, Yang et al, 2008). Graphene has unique hierarchical and physicochemical properties including a high surface area (2630 m2/g), extraordinary electrical and thermal conductivity (mobility: 20,000 cm2V-1 s-1) through the pie electron cloud makes graphene a promising material in conducting composites and quantum electronics (Bolotin et al, 2008, Morozov et al, 2008) and also possess strong mechanical strength (~1100 Gpa (Lu et al,

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.

As a result for much demands of membrane applications, the characterization of membrane properties is becoming essentially needed to expect the membrane performance in a given application. In fact, these characterizations techniques should involve both bulk and surface properties as well as the chemical as well as pore structure at

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.

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.