There are two types of lagoons treatment processes – anaerobic lagoon and aerated, or aerobic lagoons. Aerated lagoons are very common in the rural parts of the US and many other countries that are remotely located and isolated from access to large centralized wastewater treatment plants. Typically, these are 8-20 ft (2.5m – 6.0m) with 1-4 aeration cells and have a retention time of 20-40 days.
The aerated lagoons have been traditionally designed and sized for BOD removal only. However, regulations are becoming more stringent and there are new requirements for nutrient control to avoid eutrophication, in addition to tighter discharge limits for BOD and TSS. This calls for limiting the concentration of ammonia-nitrogen and total nitrogen in the treated effluent. Most lagoons cannot meet these requirements within the existing capacity and footprint and require new infrastructure. Nitrification of ammonia is very sensitive to temperatures. At temperatures below 50°C, the rate of nitrification becomes extremely slow and requires large volume to carry out biochemical reactions. In many parts of the world, in winter lagoon temperatures drop close to freezing. At such low temperatures, in conventional suspended treatment processes, nitrification effectively ceases as lagoons cannot maintain sufficient temperatures. Headworks Integrated Treatment (HIT) system is a modularized, skid-mounted system for conducting decentralized treatment of wastewater. At the heart of the HIT package is Moving Bed Biological Reactors (ActiveCell™ MBBR) that carry out the treatment reactions
The MBBR technology used by Headworks is an integrated Treatment system with specially designed ActiveCell™ media for biofilm growth. The media grows biofilm on its internal surfaces, thereby protecting it from temperature shocks due to temperature drops. The MBBR maintains and regulates temperature so that the nitrification/denitrification steps are not adversely affected.