Emory University has an on-site water recycling system unlike any other in the nation. Emory’s WaterHub uses sustainable technology which mimics natural processes to clean wastewater for non-potable uses such as heating and cooling, irrigation, and toilet flushing. Team Water from the Athens-Clarke County Water Conservation Office took a trip to Atlanta, GA for a sneak peak of the Hub’s inner-workings. Let’s dive in to the details!
The water treated at the WaterHub is diverted from an on-campus sewer pipe to the greenhouse portion of the water reclamation site. The water gets screened to remove any non-bio-degradables then goes through additional cleaning processes.
Hydroponic Treatment System
A variety of low-maintenance tropical plants are featured in the greenhouse. Their dense root systems are submerged in the wastewater and provide excellent habitat for waste-treating microorganisms to thrive. Microorganisms play a huge role in reclaiming wastewater; by consuming excess nutrients, they biologically purify the water. It is extremely important to maintain an environment that is beneficial to the microorganisms so they can break down pollutants in the water. In addition to clinging onto plant roots, microorganisms benefit from the added surface area of a BioWeb textile media (shown to the left) and honeycomb-shaped plastic pellets that move freely in the water as biofilm carriers. Microorganisms work efficiently to break down organic waste when given appropriate living conditions.
Reciprocating Wetland Technology
Tidal marsh ecosystems are mimicked at the WaterHub to provide alternating anoxic and aerobic treatment conditions. Wastewater is filled and drained in adjacent bio-cells that contain gravel. The gravel serves as microorganism habitat during this stage. The recurrent fill-and-drain sequence allows control of microbial processes.
Clarifying, Filtering, & Disinfecting
After the microorganisms complete their part of the treatment, the nearly-clean water flows to a clarifier tank and disk filter where any remaining solids, nutrients, and color are removed from the water. Some microorganisms are taken from the clarifier tank and relocated to the beginning of treatment where they repeat the process of breaking down bio solids and sludge. Once the water flows over the disk filters, only trace amounts of microorganisms remain. Ultraviolet disinfection disrupts the DNA of remaining microorganisms, making the water safe to use for non-potable demands. The ready-to-use water is delivered through a series of purple pipes to differentiate the supply from wastewater and drinking water.
Recycling Water Is A No-Brainer!
Custom, satellite wastewater reclamation facilities like the Emory WaterHub are efficient and cost-effective. Water naturally recycles in the environment, but why not extend the life cycle of water even further like the WaterHub does? On-site water reclamation reduces withdrawals from sensitive ecosystems and eliminates a significant portion of the water distribution system, thus reducing a community’s carbon and water footprints.
Let’s get on board with sustainable water reuse and make a greater effort to use water wisely! For more information about the WaterHub and Sustainable Water, visit here.
Today’s blog was written by Emily Bilcik, Graduate Assistant at the WCO.