Wastewater treatment facilities in Kentucky are facing the same problem as many other wastewater treatment facilities throughout the country – rising costs for treatment and energy usage. Along with these common issues, there are growing concerns with the environmental impact of using chlorine to disinfect a town’s wastewater. A recent development in treatment uses a pasteurization process (the same process to sanitize milk), by raising the temperature of the wastewater to 180 degrees and disinfecting it. The results from this process are a clear, clean, pathogen-free effluent that is pure enough for irrigation of food crops.
The benefits for this type of treatment include no toxic chemicals, significant cost savings and provide disinfection of wastewater for reuse. This process uses the digester gas (often referred to as biogas, a natural by-product of wastewater treatment) to drive a turbine or the engine that generates renewable electricity. The hot exhaust air from the turbine or engine energy that is typically wasted is then passed through a series of customized heat exchangers that increase the temperature of the wastewater to a level that disinfects it. Unlike many other types of treatment techniques, this method does not require toxic chemicals, such as chlorine, or costly electrical power and expensive UV lamps. The diagram below shows how the process is accomplished.
This process won the “Best of What’s New” award from Popular Science in 2011 and continues to be a process that is being integrated to many different types of industries throughout the world. Some of these industries are beer and soft drink companies, agricultural processing, food manufacturing and most importantly, municipal wastewater treatment facilities of all sizes from as low as 0.1 MGD to over 150 MGD. It’s very exciting to see that people are trying to reduce costs through new technologies and scientific research in the wastewater field. If you are interested in reading more about this technology, visit the Pasteurization Technology Group at http://www.pastechgroup.com/.