The Students: The Entire Advanced Biology Crew: Kirsten Adams, Nikki Fackrell, Shasta Bright, Tonia Roark, Sarah Tucker, Dan Dunn, Jake Durfee, Brandi Lopez, Ben Plehal, Todd Freeman, Wade Heath, Matt Worth(less), and Carrie Waldron.
The Teacher: Clinton A. Kennedy
The 1996-97 Advanced Biology class is continuing its third year of work on the experimental waste water treatment project called the Biocoil. This year we plan to build a mobile Biocoil unit to test the efficiency of the Biocoil as a tertiary sewage treatment method. According to Biotechna, the company responsible for its original development, the Biocoil is a revolutionary photosynthetic bioreactor that provides an environment for biological organisms to grow in a controlled manner. What this means is that the Biocoil enables certain types of algae, specifically Chlorella to grow and multiply in a controlled environment. When sewage water is added to the Biocoil, the theory is the nutrients in the water will be consumed by the algae, which, in turn, will use these nutrients to reproduce when they photosynthesize. Theoretically, the system will remove 92% of the phosphate and 97% of the nitrates in the water through the process of photosynthesis. After these nutrients are removed from the waste water, the water can be returned to lakes rivers and streams. With 960 of Idaho lakes, rivers, and streams deemed impacted by an overload of nutrients, a system capable of removing nutrients as quickly, efficiently, and as affordably as the Biocoil holds great promise.
The construction of the Biocoil allows the algae to photosynthesize through a series of tubes after it is held in three separate tanks. The Chlorella culture is maintained in suspension at a high concentration, causing the culture to become nutrient deficient in the holding tank. It is then mixed in a tank called the contact tank, where the "starved" algae is mixed with the sewage water. The algae is then able to absorb the nitrates and phosphates in large amounts since these nutrients are vital to the algae's growth and development. After the algae has "eaten" the nutrients, it passes through the clear PVC tubing and is exposed to sunlight and artificial lighting. When the algae is exposed to the light it is able to photosynthesize and then the nutrients it has absorbed are used to build new algae. The water is then transferred to the settling tank, where the algae settles to the bottom where it can be harvested or returned into the system. The treated water is pumped from the surface of the settling tank and is then reintroduced into lakes, rivers, and stream nutrient free.
For the last two years a group of Advanced Biology students, affectionately know as the "Sewage Sisters", has been working on the Biocoil. Their interests were aroused when they discovered the Biocoil technology in a National Geographic while looking for a solution to the problems facing the Cascade reservoir. Soon after, they made contact with Biotechna and received information about the Biocoil system. They felt this system was the answer to many of the problems they encountered while working to improve the lake's water quality. The Sewage Sisters began the legwork to implement the Biocoil as a tertiary sewage treatment method for the city of McCall because the McCall sewage treatment plant was releasing a large amount of nutrients into the river that flows into Cascade reservoir. The Sewage Sisters felt that the Biocoil was a feasible solution to McCall's sewage problems which contributed to the degradation of Cascade reservoir. However, the Division of Environmental Quality (DEQ), had told the Sewage Sisters that they would not be able to build a Biocoil until there was Biocoil research done in the United States. They tried to encourage the officials at McCall to contact the experts at Biotechna to learn more about building a Biocoil in the city of McCall. They hoped that McCall would build a pilot plant to start the process of research making it possible for the Biocoil technology to be introduced into the United States. Unfortunately McCall never pursued the meeting with Biotechna so the Sewage Sisters decided to build a model themselves. With the help of Russiell Manwaring from West Central Highlands, who took the girls under his wing, they applied for grants and received quite a few, including the Phillips Environmental Partnership (PEP). In addition, their teacher received the Toyota Tapestry award. In total, the Sewage Sisters received approximately twenty thousand dollars in grant money. This money was enough for them to start building a pilot unit to pursue their research.
With money to use and the Sewage Sisters graduated, this year's Advanced Biology class has been building a mobile unit of the Biocoil. We have finished construction of our Biocoil which includes a few major design differences than either Biotechna's original design or the Sewage Sister's plans. This mobile unit has a height of eight feet and a circumference of thirty feet. We are now ready to start experimenting with the Biocoil at the Cascade sewer lagoons. We plan to test several variables affecting the efficiency of the Biocoil. Some tests we plan to run include varying the amount of time the algae spends in the tubes exposed to light, the amount of water that can be treated in the shortest amount of time, the effect certain trace elements have on the growth of the algae culture, the ratio of phosphate and nitrate for best removal rates, and the time the algae spends in the contact tank. The tests we are going to be performing will last until next fall when we plan on writing a research paper on the Biocoil with these test results included. We also want to see how well the Biocoil will work as a sewage treatment system for home use to replace septic tank drain fields. Here are the construction plans for the Biocoil.
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