At long last, we have found an oasis for those thirsting for safe drinking water in developing countries. A galaxy of researchers at Purdue University has invented a prototype water disinfection system that could provide the world’s 800 million people with safe drinking water. The new technology uses solar UV to disinfect water.
The system uses ultraviolet radiation from the sun to kill waterborne pathogens. Sunlight is captured by the reflector and focused onto a UV-transparent pipe though which water flows continuously.
“We’ve been working on UV disinfection for about 20 years,” says Ernest “Chip” R. Blatchley III, a professor of civil engineering. Till recently, they had dealt with UV systems based on an artificial UV source, but now they are experimenting on ultraviolet radiation from the sun.
Inexpensive water-treatment technologies are a crying need of the Third World and the new technology will answer it, it is hoped.
More than 800 million people in many developing countries are forced to use water that hasn’t been treated to remove contaminants, including pathogenic microorganisms, with the result that thousands of children die daily from diarrhea and its consequences, including dehydration. Half of the world’s hospital beds are occupied by people who are sick with water-related diseases.
Prof Blatchley says that the solar radiation received in Indiana at some times of year is intense enough to inactivate some waterborne microorganisms. “We demonstrated that we can disinfect water using sunlight. The reactor was very inexpensive to build, less than $100 for the materials,” he adds.
The natural UV system inactivated E. coli bacteria. However, the system must be able to kill dangerous pathogens such as Vibrio cholerae, which causes cholera, and Salmonella typhi, which causes typhoid, and Cryptosporidium parvum, which causes cryptosporidiosis, a parasitic disease that causes diarrhea.