Experience the physical, chemical, and biological processes of a wastewater treatment plant without ever leaving the classroom. Using a non-hazardous organic solution to simulate sewage, students observe changes through the aeration, bioremediation, and filtration stages-without the odor. Students are actively engaged during the simulation by recording and graphing the decomposition of organic material over time. This easy-to-assemble unit is battery powered, making it completely portable. Everything is included to accurately replicate the workings of a real wastewater treatment plant. Refill includes consumable components. Size, 12" L x 4" W x 20 1/2" H.