Designing Efficient, Low-Cost, Eco-Friendly Activated Carbon for Removal of Heavy Metals from Water

By Alexis MacAvoy

What is the Problem? 

80% of the world’s industrial wastewater is entirely unfiltered. Lack of filtration can have disastrous effects on the environment and our health, like when mercury was dumped into the SF bay during the gold rush. It took almost two centuries and millions of dollars to clean the water, and we are still suffering from the damage in the form of bioaccumulation in wildlife. The best measure to prevent this from happening again is proper filtration. However, adequate filtration can often be costly, and lower-income regions suffer the brunt of this contamination issue. 

What is your solution? My solution is to design a cheap, accessible, and eco-friendly activated carbon capable of removing toxic heavy metals from industrial wastewater, the most significant contributor to the problem. I combined the most effective and accessible chemical treatments for synthesizing activated carbon to create an activated carbon procedure that I executed and tested. My activated carbons removed 99.67% of copper from a test copper contaminant solution, left levels of copper in the effluent below the EPA’s maximum amount of copper permitted in drinking water, and was 30 times more efficient than commercially available activated carbon. I also tested the biocompatibility of the activated carbons to confirm their safety and ensure no residual reagents would harm the environment by observing and testing their impact on phytoplankton and marine rotifers over time. The activated carbon from the coconut shell precursor turned out to have no significant difference than sand (sampled from a local healthy creek) on the plankton environments. I also designed and tested a simple, cheap prototype to observed my activated carbon in a real-world application. The coconut activated carbon was more efficient than the commercially available activated carbon. After seven minutes of draining copper test contaminant through the prototype, copper effluent reached levels below the EPA’s maximum amount of copper permitted in drinking water.

P.E.N.G.U.I.N.S: Promoting Emulsion Nullification Greenly Using Innovation Nucleation Surfaces

By Zoe Gotthold

The problem: Oil spills are environmental catastrophes--yet much of the danger comes from the less-famous emulsion that forms between spilled oil and seawater. This emulsion increases the volume of the spill, and floats underwater, threatening animals, especially penguins.

The solution: If we can separate the emulsion, the oil will float back to the surface, where it is far easier to remediate. I developed prototypes to do exactly that: reduce overall emulsion stability (by up to 25%) by passively attracting oil/water particles. Think of emulsions like a card towers, and my demulsifying devices as “card magnets” that pull out certain cards and destabilize entire towers. These devices can then be added to spill areas to protect sea life and the environment.

Microscopic Particle Detector Using Laser Microscopy and Image Processing

By Kyle Tianshi

What is the Problem? 

The invisible TSS (Total Suspended Solids) in water source is becoming a problem with ever-growing plastic contamination. 83% of bottled water and 93% of tap water contain microplastics. My goal was to develop a TSS detector that could measure invisible particles. 

What is Your Solution?

Utilizing an innovative combination of lasers and video image processing, I proved the concept that it is feasible to develop a TSS detector that can measure invisible articles as small as 0.1 microns at concentration of 10ppm. The measurement is accurate and fast. I build a mockup design with a cost of $35 when purchasing individual parts from Amazon. I expect the cost will go down to as low as $15 for mass production.