S&N AIROFLO of Greenwood, Mississippi, has been manufacturing floating horizontal rotor aerators since the 1970s. The company began installing their aerators in municipal and industrial wastewater lagoons in the mid-1980s. The aerators have been improved over the last 30 years to enhance performance, ease of maintenance, reliability, and durability. S&N aerators have been used successfully in hundreds of lagoon systems since the mid-l 980s and hundreds of activated sludge processes throughout the U.S. since the early 1990s. Most of the treatment facilities using S&N floating horizontal rotors are located in the southeastern and southwestern U.S. 
S&N aerators have an extremely good Standard Oxygen Transfer Rate (SOTR), which makes them ideally suited for biological wastewater treatment systems. The third party verified SOTR for S&N horizontal aerators is 3.0 lb/(hp-hr). The units can be easily placed in oxidation ditches and conventional activated sludge reactors to provide oxygen for CBOD and NBOD removal. They also can be used in equalization basins and aerobic digesters. The greatest application during the last 30 years has been in oxidation ditches. When old fixed horizontal rotors or vertical turbine aerators in oxidation ditches fail, S&N aerators can be easily placed in the ditches to satisfy oxygen requirements and mixing requirements, and this can be done in a highly cost-effective manner. Hot-dipped galvanized S&N aerators and stainless-steel S&N aerators are available options. The units are available in sizes of 5 HP to 30 HP. 
Another unique product of S&N AIROFLO is the S&N BIOFLO unit. The original concept of the BIOFLO was developed by Dr. Larry W. Moore in 2006. The first proto-type was constructed by S&N in 2006 according to Dr. Moore's concept. The BIOFLO unit is a floating rotating biological contactor (RBC) that is used in small wastewater lagoon systems to achieve biological nitrification. Each BIOFLO unit is 4.5 feet in diameter and 10 feet long and has 2,400 m2 of attached growth surface area. Kontakt media (with UV inhibitors and greater surface area) is used to provide excellent fixed-film surfaces to promote the growth ofnitrifying bacteria in the last cell of multi-cell lagoon systems. The largest BIO FLO treatment system (0.25 mgd average daily design flow rate) is currently being constructed in Wedowee, Alabama, to meet stringent ammonia-N limits during summer conditions. S&N BIOFLO units have been used in several small lagoons systems in Mississippi in the last 15 years to help small cities meet relatively stringent ammonia-N limits and to avoid the high cost and high maintenance requirements of activated sludge processes.