In the USA, we have effective centralized water treatment and distribution systems. Water is available in taps in our homes and work 24/7. The water has a chlorine residual to prevent consumption of pathogenic microorganisms. The effluent water from treatment plants is highly regulated to insure public safety. Unfortunately, 2-3 billion people in the world do not have this level of service, mostly because of economic constraints in Asia and Africa. As a consequence more than 1.5 million children die annually from poor quality drinking water. The World Health Organization has suggested that decentralizing water treatment, e.g. allowing people to treat their water in their homes right before consumption, is a potential solution to this global problem. Developing such household, or point-of-use (POU) water treatment technologies, however, is a challenging design problem. Successful designs must be technology effective, socially acceptable, extremely inexpensive, and very simple to use. Over the past few years, a water treatment technology called the MadiDrop has been developed. The MadiDrop is a porous ceramic tablet infused with silver. Silver is a highly effective antimicrobial agent that can disinfect the stored household water.
Although the MadiDrop is a successful and promising water treatment technology, it has limitations. Silver is highly effective against bacterial pathogens, but much less effective against viral pathogens like rotavirus and adenovirus. Another disadvantage of the MadiDrop is that it does not remove other natural chemical pollutants, including fluoride and arsenic, which are global public health hazards. This research explores improvements to MadiDrop such as combining silver ions and chlorine, pathogen disinfection is highly effective for all classes of microorganisms, and low-cost effective sorbents for fluoride and arsenic, including hydroxy-appatite (bone char), activated alumina, and calcinated oyster shells.
