Jacob Marrocco

 

KINGSTON, R.I. -- According to the World Health Organization, approximately one in eight people do not have access to clean water.  Dr. Vinka Oyanedel-Craver, assistant professor of civil and environmental engineering at the University of Rhode Island, is out to reduce that number one nanoparticle of silver at a time.

 

Water-borne illnesses, according to WHO, are responsible for almost two million deaths worldwide every year, with 80 percent of those killed under the age of five.  Dr. Craver’s methods for reducing these numbers substantially can be traced back to one element:  colloidal silver.

                

Dr. Craver said that the use of colloidal silver, which is small nanoparticles of silver suspended in liquid, has been seen in filtration systems in Central America since the 1980s.  Silver has been used to naturally kill bacteria for millennia, dating back to Ancient Egypt where bottles made of the element would store wine.

                

Since 2006, she has visited the Mayan community of San Mateo Ixtatan in Guatemala and experimented with the infusion of nanosilver into clay pots to help filter harmful contaminants out of the water.  The procedure is easy:  the pot itself allows the water to flow out, while the silver essentially eradicates any trace of bacteria.

                

The most effective part of the design is its simplicity. Local factories in Guatemala produce the clay pots for a cheap price tag; while the somewhat expensive silver has natural cleansing qualities that help it eliminate bacteria. Her studies have revealed that these nanosilver filters in most cases have destroyed 99 percent of contaminants in water.

                

“Now we need to think about what is going to come after this system,” Craver said. “The system that we implemented, it doesn’t clean the water completely. So we need to do further treatment in order for the water to be safe to discharge in the river.”

                

While these numbers are impressive, Dr. Craver said that there is further room for improvement. Her main focus for now is to try to minimize the amount of silver being used in the filters while still attempting to increase the bacteria the system can remove.

                

A possible advancement that she would like to make when she visits Guatemala again would be to build systems with fewer movable parts.  She said that, while it does not affect the overall quality of the work performed, the original filters constructed were too intricate for the basic needs of the families in the house.

                

Varun Kasaraneni, a graduate student from India working with Dr. Craver, added that these filters can be seen around the world and are constantly being improved.

                

Kasaraneni, who will be receiving his Ph.D. in waste water management in the spring, said that numerous areas of Africa have seen the use of clay pots combined with nanosilver particles to eliminate harmful bacteria in their water. According to The Water Project, more than 884 million people in Africa do not have access to potable water.

                

“In India, they have similar types of systems like ceramic filters,” Kasaraneni said. “They’ve been using them and different types of filters. [Nanotechnology] is being used in all parts of the world, including Africa and Indonesia; especially silver.”

               

Kasaraneni echoed the words of Dr. Craver when he said it is vital to make advancements on the way in which the silver is impregnated into the clay pots so that less silver is lost in the filtration. Also, another sight for this worldwide project is to possibly provide small amounts of hydroelectricity to people who live in the mountainous regions of Africa without access to power.

                

While Dr. Craver said that vast improvements have been made and that these systems have destroyed billions of bacteria, the perfect system does not exist.  If users want to ensure that they have potable drinking water every time, it is important to clean the system thoroughly. If not, silver can leak into the rivers and streams and kill non-malicious types of bacteria.

                

“Silver is expensive, so if you add silver to something you want it to stay there,” Craver said. “You don’t want it to wash out in the first batch of water that you treat. You want the silver to stay in the filter and do what it is supposed to do:  kill the bacteria. You don’t want them to be out or drunk in high amounts.”