The microbial contamination of building water supply system is very common all over the world. Among those 29 common waterborne pathogens, Legionella pneumophila, Campylobacter jejuni and Mycobacterium species have a relatively high infectivity according to WHO. Water disinfection technologies such as chlorination, ozonation, UV exposure and reverse osmosis are now widely used in drinking water disinfection. However, these technologies do not just alter the quality and taste of drinking water, they are effective only under certain conditions which are often not feasible in a building water supply system. The discovery of Legionella in the water from the taps of Hong Kong's brand new government headquarters illustrates the gravity of the situation and its potential threat to publ...[ Read more ]

The microbial contamination of building water supply system is very common all over the world. Among those 29 common waterborne pathogens, Legionella pneumophila, Campylobacter jejuni and Mycobacterium species have a relatively high infectivity according to WHO. Water disinfection technologies such as chlorination, ozonation, UV exposure and reverse osmosis are now widely used in drinking water disinfection. However, these technologies do not just alter the quality and taste of drinking water, they are effective only under certain conditions which are often not feasible in a building water supply system. The discovery of Legionella in the water from the taps of Hong Kong's brand new government headquarters illustrates the gravity of the situation and its potential threat to public health.

This project aims at designing a pulsed electric field disinfection device, which is environmentally benign and safe for point-of-use disinfection of tap water based on the poration of microbial cell wall under electric field. Pulsed electric field disinfection technology avoids the use of chemical disinfectants that can alter the quality of the drinking water and induce resistant in microorganisms. Current technology uses super high input voltage (>2kV) as the key disinfection parameter. This project focuses on designing a low voltage device ( <100V) to attain 90 percent bacteria reduction in the batch test with the help of micro-engineered electrode. Two AA batteries are sufficient to power the device perform disinfection for more than four months. It is believed that this device does not just bring benefit to the people in modern cities, but can also be the key to control the spread of water-borne diseases in most of the developing countries.