Potential of carbon nanotubes in water purification: an approach towards the development of an integrated membrane system
10 Sep 2008-International Journal of Nuclear Desalination (Inderscience Publishers)-Vol. 3, Iss: 2, pp 143-150
TL;DR: In this paper, the authors assess the potential of carbon nanotubes (CNTs) as an emerging technology in water purification system, particularly with respect to its potential for the removal of arsenic, fluoride, heavy metals and toxic organic components.
Abstract: The problems of water shortages and lack of access to safe drinking water have been and will continue to grow as major global problems. To alleviate these problems, water purification technologies are being updated. Recent years have witnessed impressive breakthroughs towards practical application of nanostructured materials such as Carbon Nanotubes (CNTs) in the field of water purification owing to their unique thermal, electrical and mechanical properties. These nanoscale structures need to be arranged into well-defined configurations in order to build integrated systems with high efficiency (the nanotubes being reusable, whereas the traditional membranes foul easily and require frequent replacements), high flux (owing to the hydrophobic super smooth inner surface of nanotubes), and with improvements in chemical selectivity (through suitable chemical functionalisation of the CNTs), so that the idea of using CNTs in separation technology can be made realistic and the potential benefits of practical application of these unique materials can be exploited. This paper assesses the CNTs as an emerging technology in water purification system, particularly with respect to its potential for the removal of arsenic, fluoride, heavy metals and toxic organic components.
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TL;DR: Based on the studied literature it appears that POU based CNT technology looks promising, that can possibly avoid difficulties of treating biological contaminants in conventional water treatment plants, and thereby remove the burden of maintaining the biostability of treated water in the distribution systems.
632 citations
TL;DR: In this paper, the authors reviewed the possible applications of the nanoparticles/fibers for the removal of pollutants from water/wastewater and made recommendations based on the current practices of nanotechnology applications in water industry for a stand-alone water purification unit for removing all types of contaminants from wastewater.
Abstract: The rapidly increasing population, depleting water resources, and climate change resulting in prolonged droughts and floods have rendered drinking water a competitive resource in many parts of the world. The development of cost-effective and stable materials and methods for providing the fresh water in adequate amounts is the need of the water industry. Traditional water/wastewater treatment technologies remain ineffective for providing adequate safe water due to increasing demand of water coupled with stringent health guidelines and emerging contaminants. Nanotechnology-based multifunctional and highly efficient processes are providing affordable solutions to water/wastewater treatments that do not rely on large infrastructures or centralized systems. The aim of the present study is to review the possible applications of the nanoparticles/fibers for the removal of pollutants from water/wastewater. The paper will briefly overview the availability and practice of different nanomaterials (particles or fibers) for removal of viruses, inorganic solutes, heavy metals, metal ions, complex organic compounds, natural organic matter, nitrate, and other pollutants present in surface water, ground water, and/or industrial water. Finally, recommendations are made based on the current practices of nanotechnology applications in water industry for a stand-alone water purification unit for removing all types of contaminants from wastewater.
552 citations
Cites background from "Potential of carbon nanotubes in wa..."
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...Many researchers observed an extremely high adsorption rate of bacteria by single-walled CNTs, in addition to their high sorption capacities by many researchers [236–244]....
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TL;DR: The carbon nanotube (CNT) represents one of the most unique inventions in the field of nan - otechnology as mentioned in this paper, which makes them useful as fillers in different materials such as polymers, metallic surfaces and ceramics.
Abstract: The carbon nanotube (CNT) represents one of the most unique inventions in the field of nan - otechnology. CNTs have been studied closely over the last two decades by many researchers around the world due to their great potential in different fields. CNTs are rolled graphene with SP 2 hybridization. The important aspects of CNTs are their light weight, small size with a high aspect ratio, good tensile strength, and good conducting characteristics, which make them useful as fillers in different materials such as polymers, metallic surfaces and ceramics. CNTs also have potential applications in the field of nanotechnology, nanomedicine, tran - sistors, actuators, sensors, membranes, and capacitors. There are various techniques which can be used for the synthesis of CNTs. These include the arc-discharge method, chemical vaporize deposition (CVD), the laser ablation method, and the sol gel method. CNTs can be single-walled, double-walled and multi-walled. CNTs have unique mechanical, electrical and optical properties, all of which have been extensively studied. The present review is focused on the synthesis, functionalization, properties and applications of CNTs. The toxic effect of CNTs is also presented in a summarized form.
345 citations
TL;DR: This work aims at precisely quantifying the characteristic large slip length and flow rate of water flowing in a planar graphene nanochannel using the intrinsic interfacial friction coefficient between water and graphene found from equilibrium molecular dynamics simulations.
Abstract: Data for the flow rate of water in carbon nanopores is widely scattered, both in experiments and simulations. In this work, we aim at precisely quantifying the characteristic large slip length and flow rate of water flowing in a planar graphene nanochannel. First, we quantify the slip length using the intrinsic interfacial friction coefficient between water and graphene, which is found from equilibrium molecular dynamics (EMD) simulations. We then calculate the flow rate and the slip length from the streaming velocity profiles obtained using non-equilibrium molecular dynamics (NEMD) simulations and compare with the predictions from the EMD simulations. The slip length calculated from NEMD simulations is found to be extremely sensitive to the curvature of the velocity profile and it possesses large statistical errors. We therefore pose the question: Can a micrometer range slip length be reliably determined using velocity profiles obtained from NEMD simulations? Our answer is “not practical, if not impossible” based on the analysis given as the results. In the case of high slip systems such as water in carbon nanochannels, the EMD method results are more reliable, accurate, and computationally more efficient compared to the direct NEMD method for predicting the nanofluidic flow rate and hydrodynamic boundary condition.
189 citations
TL;DR: In this article, a substantial amount of work have been carried out with impregnation of CNTs (simply as one of the reinforcements for incorporation of better properties like antibiofouling and/or better strength, etc.) in polymer host matrix.
182 citations