drinking water filtration

Improving Water by Removing Arsenic

By Marguerite Huber

Arsenic removal system, Twentynine Palms, CA.

Arsenic removal system, Twentynine Palms, CA.

If you lead an active and busy life like me, you probably don’t spend a lot of time thinking about what is in the water you drink. You just fill up your water bottle and are out the door.

But behind the scene a lot goes into making our water safe to drink. To protect public health, EPA regulates arsenic in drinking water. Arsenic is a semi-metal element that can enter drinking water supplies through natural deposits or from agricultural and industrial practices. Health effects due to prolonged excess exposure can include skin damage, circulatory system problems, and increased risk of cancer.

EPA initiated the Arsenic Removal Technology Demonstration Program to evaluate the performance, reliability, and cost of arsenic removal and the effect on water distribution systems. One type of arsenic removal system consists of a tank of adsorptive media that is similar to a home water softener.

As the water passes through the tank of media, the dissolved arsenic adsorbs on to surface of the media. Adsorption is not to be confused with absorption, which is the process in which a fluid is dissolved by a liquid or solid, such as water being absorbed by a sponge.

Adsorption on the other hand is the process in which atoms, ions or molecules, stick to a surface. Once the media reaches its arsenic removal capacity, the media must be replaced. Many water systems, such as the Twentynine Palms Water District in California, have experienced high operating costs due to frequent replacement of the adsorptive media.

EPA researchers partnered with Battelle to conduct lab and pilot studies to investigate the possibility of these media being reused to reduce costs. The study found that as much as 94% of the arsenic from exhausted media could be removed and the media could be regenerated.

Following the successful results of the laboratory regeneration study, EPA and Battelle demonstrated the efficiency of media regeneration in Twentynine Palms, CA. The testing led to substantial reductions in the operational cost, proving to be successful and that regeneration can work.

The goal of this research was to reduce operating costs, and since starting the regeneration program in 2010, Twentynine Palms Water district has been saving about $20,000 a year.

All in all, there is a lot of science and technology that bring you the clean water in your water bottle.  I’m now going to stop and appreciate that each time I fill up my water bottle.

About the authorMarguerite Huber is a Student Contractor with EPA’s Science Communications Team.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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My Confidence in Future Young Scientists

By Thabit Pulak

EPA guest blogger Thabit and friends

The students were taking part in “enrichment clusters,” sessions in which they learn about one important public issue in depth. I was invited by 2nd-grade teacher Ms. Claborn to visit her cluster on water purification and to present a real-life example of a water filter.

I had recently worked to develop an affordable filter that removed not only bacteria and contaminants from water, but also arsenic, a poisonous substance that affects nearly 150 million people across the world today. I had the opportunity to present my water filter at the 2012 Intel International Science Fair, where I won 3rd place and EPA’s Patrick J. Hurd Sustainability Award. The Hurd Award included an invitation to present my project at the annual National Sustainable Design Expo, which showcases EPA’s People, Prosperity, and the Planet (P3) program.

STEM in the classroomI presented the filter to the class and answered questions, learning just as much from them as they did from me.  I was invited to stay for the remainder of the cluster, where the students were putting final touches on their own water filters. Ms. Claborn gave each of the students some muddy water to run through the filters. It was exciting for me to see the children’s smiles as they looked at the clean water slowly trickling out of the open edge of the soda bottle after traveling through the sand and rocks. The filters were based on a water filtration activity that EPA designed specifically for students.

Afterwards, I was invited to attend the upcoming STEM (Science, Technology, Engineering, and Math) exhibit that the school was hosting. The students’ mini filters would be on display, and I was invited to display my filter alongside theirs. As the stream of curious parents and students came in, I gladly talked about both what the students did and my own filter, and what this means for the future of environmental sustainability issues like water.

This was my first opportunity to present my work outside of my school and science fairs. I felt very honored and happy to be able to give something back to the community. I hope to find ways to keep doing so!

 

About the Author: Guest blogger Thabit Pulak of Richardson, Texas was the winner of the Patrick H. Hurd Sustainability Award at the Intel International Science and Engineering Fair (Intel ISEF) 2012. As part of this award, he was invited to attend and exhibit at the National Sustainable Design Expo, home of the P3: People, Prosperity and the Planet Student Design Competition for Sustainability in Washington, DC. He was also the recipient of the 2013 Davidson Fellows Award

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.