Providing a suitable environment for microorganisms to treat wastewater is what aerobic treatment units (ATUs) are all about. These advanced systems outshine alternatives on tight lots where there is no room for conventional treatment and on sites with poor soils, shallow vertical separation distances to limiting conditions, and horizontal setback restrictions. Some systems can be designed for the treatment of high-strength wastewater or where total nitrogen removal is required.
The effluent produced by an ATU is a higher quality than septic tank effluent with significant improvement in biochemical oxygen demand (BOD), total suspended solids (TSS), ammonia reduction, and, in some instances, total nitrogen (TN) removal. With mechanically induced aeration and mixing within the unit, oxygen concentrations of about 2 mg/L or 2 ppm are achievable. This oxygen and mixing enables the microorganisms to break down the organic portion of the waste.