Nanotechnology, the engineering and art of manipulating matter at the nanoscale (1-100 nm), offers the potential of novel nanomaterials for treatment of surface water, groundwater and wastewater contaminated by toxic metal ions, organic and inorganic solutes, and microorganisms. 
An adequate supply of safe drinking water is one of the major prerequisites for a healthy life, but waterborne diseases is still a major cause of death in many parts of the world, particularly in young children, the elderly, or those with compromised immune systems. 
Electrospun nanofibers and nanobiocides show potential in the improvement of water filtration membranes. Biofouling of membranes caused by the bacterial load in water reduces the quality of drinking water and has become a major problem.Nanobiocides such as metal nanoparticles and engineered nanomaterials are successfully incorporated into nanofibers showing high antimicrobial activity and stability in water. Research on the applications of nanofibers and nanobiocides in water purification, the fabrication thereof and recently published patents are reviewed in this article.
Sessile communities of bacteria encased in extracellular polymeric substances (EPS) are known as biofilms and causes serious problems in various areas,
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Water Filtration Paragraph:
Irrigation plays a major role in agriculture and words cannot stress enough the importance of a clean supply of water. Many procedures have been undertaken towards the treatment of water and nanotechnology also has a part to play. Nanotechnology can be used to remove alluvium, chemical effluents, bacteria and other microbial threats and organic contaminants. With regards to water purification, the most important nanomaterials are carbon nanotubes and alumina fibres.
Carbon Nanotube Filters:
Carbon nanotube filters can achieve high water flux at very low pressures and can strongly attract polar water molecules while all pollutants are rejected on entry.  Their main advantages are having a high energy efficiency rate, a strong antimicrobial activity and a tuneable pore size and surface chemistry. The two types of carbon nanotubes are single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs).  SWCNTs have a cylindrical shape consisting of a single shell of graphene while MWCNTs consist of multiple layers of graphene sheets. Carbon nanotube filters can achieve high water flux at very low pressures and can strongly attract polar water molecules. CNT filters provide water flow  with little to no friction through them while all pollutants are rejected upon entry. The inner hollow cavity of CNTs provides a great possibility for desalinating water. The high aspect ratios, smooth hydrophobic walls and inner pore diameter of CNTs allow ultraefficient transport of water molecules. Carbon nanotube filters can achieve high water flux at very low pressures and can strongly attract polar water molecules. Their main advantages are having a high energy efficiency rate, a strong antimicrobial activity and a tuneable pore size and surface chemistry.
*diagram and explaination of diagram*
In their research paper "Nanotechnology for Water Purification" published in 2010 in the International Journal of Nuclear Desalination, colleagues Alpana Mahapatra, Farida Valli, and Karishma Tijoriwala state: "The main advantages of using nanofilters, as opposed to conventional systems, are that less pressure is required to pass water across the filter, they are more efficient, and they have incredibly large surface areas and can be more easily cleaned by back-flushing compared with conventional methods." 
Alumina Fibres: