Bioethics Panel

We hosted a Bioethics Panel, where we invited students and teachers to discuss the moral, social and environmental concerns of our project. To encourage participants to consider the problems from multiple perspectives, we created a role-playing game and assigned different roles to participants. We then asked for their opinions on nanoparticle usage and disposal from the perspective of their assigned role. (Whole team activity)

For instance, one of our questions was:

“Dihua WWTP has no nanoparticle removal plan. Should this be the job of the wastewater plant? Or the nanoparticle manufacturer?”

The following roles were assigned:

• Wastewater plant manager
• Nanoparticle manufacturer
• Citizen
• Fisherman
• Fish

Apex Nanotek

To learn more about the applications of nanoparticles, we visited a nanotech company that uses silver nanoparticles to make various antimicrobial products. The researcher and manager of Apex Nanotek, Chery Yang, introduced us to their main product, which is antimicrobial nanosilver activated carbon. Pure activated carbon, commonly used to treat sewage and industrial exhaust, is prone to bacterial growth. To overcome this problem, they integrate crystallized nanosilver into the activated carbon for their antimicrobial effects. One of their products is a showerhead, with nanosilver activated carbon filters to kill bacteria when water flows through the showerhead.

We tested the product by comparing SEM images between tap water and filtered water from the showerhead. The showerhead decreased the number of bacteria and larger particles from tap water! However, we also observed the release of nanoparticles from the filter, which will flow into wastewater. (Interviewed by Christine C., Kelly C., Yvonne W., Chansie Y., and Justin Y.)

Chery Yang (third person from the left), the main researcher of Apex Nanotek Corporation

The image on the left shows a tap water sample under the SEM, in which we observed some bacteria (round objects that are approximately 1 μm in diameter). The SEM image on the left shows water that was filtered by the showerhead from Apex nanotek. There is less bacteria as the showerhead uses embedded nanosilver antibacterial filters. (SEM images: Christine C. and Florence L.)

WWTP -- Dihua Wastewater Treatment Plant

In order to learn firsthand about the effect of nanoparticles in WWTPs, we visited the Dihua WWTP (迪化污水處理廠). Here, we were given a tour around the plant, and were able to ask questions to the managers and people that work there. They confirmed that the current facilities are unable to remove nanoparticles from wastewater mainly due to their small size. In addition to this information, they kindly provided us with samples of sludge, effluent water, and the polymers they add during wastewater processing. Throughout the year we visited and talked to the Dihua WWTP several times about where and how our project could be implemented in their current system. These conversations and visits played a huge role in shaping our construct design, prototype design, mathematical modeling and overall purpose for our project. (Whole team activity)

Boswell Wastewater Treatment Plant

Not all WWTPs are as large as the one in Taipei. One of our advisors (Jude Clapper) went to visit the Boswell WWTP in rural southwestern Pennsylvania. We learned that the same processes that occur in the Taipei Dihua WWTP also occur in the Boswell WWTP, but with different water flow rates and waste quantities. Because of the similarities in how both WWTPs process their wastewater, It inspired us to create our current prototype design that is a rotating polymeric bioreactor coated in biofilm. This prototype will be placed in the secondary sedimentation tank, where the majority of organic solids have been removed and only smaller particles exist. The Boswell WWTP also confirmed that since our project is bacteria-based, it will be killed by UV light and chlorine in the disinfection tank, similar to the Dihua WWTP, before the water turns into effluent and goes to the rivers and oceans.

Thomas J. Brown

Thomas J. Brown, the Water Program Specialist of the Pennsylvania Department of Environmental Protection (DEP) occasionally helps with the Boswell Wastewater Treatment Plant. He has also worked with the EPA in Taiwan on wastewater treatments. We interviewed Mr. Brown about our methods to clean nanoparticles in wastewater treatment plants and how to achieve our goal of implementation. With his expertise in the field of wastewater treatment, he provided us some suggestions as to how we could turn our project into reality.

For example, we asked him if there were differences between rural and urban plants that we should take into consideration when thinking about implementing our project. He responded that the biological processes used for treatment remains the same regardless of facility size. This helped us think about and design our final prototype, which can potentially be used in both rural and urban treatment plants.