Hello everyone, I hope you all are having a great summer! Though my summer has been pretty stressful and busy, it is going well. I am currently taking 3 classes while working on my IDEA Grant project. As I mentioned in my first blog post, my project is about removing selenium from wastewater. Selenium is a nonmetal chemical element commonly found in wastewater, particularly in power plants. When present in large amounts, it is known to be highly toxic and the cause of reproductive failure and hair loss. If selenium is removed from the water, it may be used for the production of glass, alloys, steel, and even oil. It can be removed from water using various biological processes such as reverse osmosis, ion exchange, and zerovalent iron treatment. But using these particular processes has been proven to be costly and environmentally destructive.
So, to address this issue, I am working alongside my UROP research mentor, Dr. Youneng Tang, and his team of graduate students to create a water treatment system consisting of three different units: a biological reactor, a bacterium selenium nanoparticle (SeNP) separator, and a tangential flow ultrafiltration module (TFU). The system will be an inexpensive and a sustainable way to remove selenium from wastewater with the help of bacteria.
This summer, I have been familiarizing myself with the instruments needed to run my experiments. I have to work closely with one of my graduate mentors to learn more about the water treatment system. I have been going into the lab every week. I have also been running experiments with the first part of the system with my graduate mentor. We have been preparing the media (synthetic wastewater), checking for any leakage, changing the tubes of the system, and preventing any contaminations since we are using bacteria. We have also been collecting several samples to analyze the ions present in the water. This helps us figure out how often the bacteria needs to be fed and if the system is operating the way it is supposed to. Lastly, we have been analyzing if any methane gas is being produced every time the synthetic media is pumped through the system.
Because of COVID-19 and the vendor’s location, it took a while to receive the materials. But they have finally come in this week. Unfortunately, I do not have any pictures for you all to see. But I have been brainstorming on how I will build the second part of the system. I will be able to start assembling the whole system and run experiments this month if all goes well.
My procedure will go as follows. First, I will begin by pumping synthetic agricultural contaminated wastewater into the biological reactor. While in the reactor, the contaminated water will undergo treatment and the selenate in the water will be converted to selenium nanoparticle (SeNP). The treated water and the SeNP will then be transferred into a bacterium/SeNP separator. There, a separation of the SeNP and bacteria will take place. The SeNP will be separated from the bacteria and will remain on a polyethylene sheet that will be angled at 45 degrees to assist with the separation process. The bacteria will drop to the bottom of the separator while the treated water will be transferred and pumped through a tangential flow ultrafiltration module (TFU) to filter out any remaining toxins. Once the water is successfully filtered and cleaned, it will be released into a separate reservoir leaving it selenium and bacteria free. The water still containing particles of bacteria and SeNP will be recycled back into the system for treatment again.
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