Water sources in slums, refugee camps, and other areas need to be tested for purity. Either before purification (for immediate use) or post purification, ensuring efficacy of purification methods. As the sources can be many different sizes (from a pan all the way up to a drum or pool) the consumption of the water needs to be minimal or nonexistant.
This isn't necessarily a true story, but represents a situation that could actually exist:
A slum near Mexico City has one water source which springs from a former mine. Water is collected in drums for consumption. After being shown how to purify the water, the device would be able to show that pre-test contaminants exist, and post test the water is clean and potable.
The contaminants that need to be detected include:
1.) Organics: Pesticides, nerve agents, petrolates, other types of organic chemicals
2.) Biological: Cholera, dysentary, other bacterial infections. Protozoal and parasitic infections are also included in this category.
3.) Heavy Metals: Existance of heavy metals found in water supplies
The device should be able to operate without any type of data connection (internet, wireless, etc.). In addition, not needing batteries would be a plus. Solar power or kinetic power would be fantastic.
- Additional things that could cause problems would be great to measure also, such as turbidity.
- Field cleanable with simple construction is grrrrreat
http://www.rhok.org/problems/water-purification-mobile-application
http://www.rhok.org/problems/poor-water-quality-water-quality-detection
These projects define similar but perhaps don't address exactly the same things. Also to come are postings of research into different types of electro-chemical sensors (mostly thick-film sensors for heavy metals)
Next steps for this problem are getting prototypes of devices that will be able to perform tests of the water. Documentation of the sensors should be gathered and posted, along with their ability to provide sufficient evidence of the presence (or lack thereof) within the source of water.