What am I looking at?  This is an ecological-machine that reduces water consumption in the Aiken Center by treating the building’s sewage and then returning grey water to flush the toilets. Eco-machines are designed and assembled ecosystems directed toward a human use. The technology has been applied to other areas like aquaculture, food processing, industrial, and environmental wastes. What you are looking is actually three Eco-Machines, allowing the system to function as a research tool.

Stages of Treatment in the eco-machine system (Step #1 primary settling)  It all starts when a sink, a toilet, or a shower is used in the Rubenstein Building. This draining water flows down into a 3,000 gallon septic tank. In the septic tank, heavier solids sink to the bottom, while fats and lighter solids float to the top. The water on the bottom and the top is blocked off from going further, and the water from the middle is allowed to move on to the next step.

Closed Aerobic Cells (Step #2)  Dirty water flows from the septic tank outside into the large white closed aquatic cells you see in the background. THIS IS THE FIRST TREATMENT stage that you see in the room. These tall white tanks hold approximately 800 gallons. This water is being circulated and aerated in these tanks with air diffusers, bubbling just like in your home aquarium. These bubbles are full of oxygen which helps drive out odors from the dirty water and prevents new anaerobic (without oxygen) odor generation. The oxygen also speeds up microbial activity, increasing the breakdown of polluants. It is important that these tanks are sealed off from the atmosphere because otherwise the stench of the fluids would escape and fill the entire building. The exaust air and odors from these tanks are vented into the bio-filters, where plants and other organisms break down and absorb the smell. Once this water is oxygenated and no longer smells, it will then move to three open-top aerobic tanks.

Bio-filters  What happens to all of the smelly gases produced by the human waste processed by the Eco-Machine? We can’t vent them inside, as nobody would ever want to enter the Aiken Center, and we can’t vent them outside, as passing students would have to smell them. The solution is a series of Bio-Filters. Bio-Filters clean the gas by allowing it to rise through a combination of limestone, mulch, and compost, releasing the remaining air into the machine room. The Bio-Filters are so effective that you will never smell a thing.

Open Aquatic stage (Step #3)  After the closed aerobic tanks, the water flows through a series of three clear-sided, open aerobic tanks, like beads on a necklace. These tanks contain vegetation on the top that is held up by a fiberglass plant rack. Diverse vegetation provides a large surface area for microbial growth and niche space for many small creatures. The plants also perform nutrient uptake and can process some of the nitrogen in the water. It is home to a variety of aquatic micro-organisms, invertebrates, and wetland plants that work together to break down pollutants and use the nutrients in our sewage for their own benefit. When the water leaves here and enter the wetland, it is relatively clean but not yet clear, as it is full of plankton, algea, and plant bits.

Wetlands (Step #4)  The final treatment stage you can see though this window is a constructed wetland. The water is sent to a wetland head box that sits on top of four and half feet of gravel. The water flows upward through the gravel substrate and root zones of the wetland plants. This filters out all the particulate matter and the microbes coating all the gravel and roots polish the water.

Sand Filter  After the wastewater has traversed most of the Eco-Machine, the majority of toxins have been removed. However, there are still particulates and a few toxins that must be removed before the water can be re-circulated. Sand has the ability to filter out many of these remaining toxins and particulates, so near the end of the Eco-Machine cycle, the water is pushed through special Sand Filters. These allow the disinfection of the water to proceed quickly and efficiently.

UV Disinfection  There is still one final step before the water can be re-circulated. Some bacteria, fungi, viruses, and pathogens have the ability to slip through all of the systems of the Eco-Machine. However, Ultraviolet Light has the ability to kill these remaining pathogens, so the final step of the disinfection process is to circulate the water through a UV treatment unit, which bombards the flowing water with short-wave, Ultraviolet Light, making the water safe for reuse.