A new wastewater treatment system called the circulating fluidized bed bioreactor (CFBBR) was tested in a pilot study to treat septic tank effluent in an urban area. The system was able to remove at least 92% of organic matter, 97% of ammonia, and 82% of nitrogen from the wastewater. This resulted in an effluent with very low levels of pollutants, making it a great option for treating urban wastewater in a compact and efficient way.