Nanofilters for Clean Water. STEM ED/CHM Nanotechnology 2009. Today’s Agenda. The problem: adequate clean water Kinds of filters Desalination of salt water Cleaning polluted water Hands on nanofiltration experiment. The Problem: Adequate Clean Water.
STEM ED/CHM Nanotechnology 2009
Despite the apparent abundance of clean water in most of the US and the developed world, more than 20% of the Earth’s population lacks clean, safe drinking water.
Repairs to the leaky distribution system from the Quabbin Reservoir located in Western Massachusetts have reduced the demand for new supplies for the Boston area.
Window and door screens are filters – they let air in and keep out insects
Dryer filters remove lint
Air conditioning and furnace filters remove dust
Coffee filters block the grinds
Air, oil, fuel, and other filters remove harmful materials
Microfiltration water plant, Petrolia, PA
A microfilter membrane
Sources: http://www.waterworksmw.com/rack%201%20&%202b.jpg http://www.imc.cas.cz/sympo/41micros/Image126.gif
An ultrafiltration plant in Jachenhausen, Germany
Nanofiltration water cleaning serving Mery-sur-Oise, a suburb of Paris, France
Abu Dhabi Emirate
Water is recovered from urine by distillation in a system installed in 2008 to reduce the amount of water that needs to be launched.
More water molecules strike the membrane on the pure water side (left), causing a net diffusion of water across the membrane. The water level rises until equal numbers of water molecules travel in each direction.
Kane and Sternheim General Physics
Racks of elements containing reverse osmosis membranes (Israel). This plant produces 13% of the country’s domestic water supply.
Image of a nanomembrane
Chemicals toxic to bacteria could be implanted in nanomembranes
Electricity moving through a membrane