A Submerged Attached Growth Bioreactor for Decentralized Wastewater Treatment

The Amphidrome® process is a submerged attached growth bioreactor (SAGB) that has been used in Massachusetts, Connecticut, Rhode Island and New Jersey for decentralized wastewater treatment systems ranging in size from 440 gpd to 150,000 gpd. The two primary advantages of a SAGB are the small volume requirement and the elimination of downstream clarification. Five years of data from four plants operating in Massachusetts are presented below. Each facility was designed to treat a domestic wastewater to an effluent BOD5 ≤ 30 mg/l, TSS ≤ 30 mg/l, and total nitrogen ≤ 10 mg/l. The process is described and the performance, including loading and removal rates, at the four treatment plants is presented. The results indicate 1) 97% nitrification at an organic loading of 2.5 kg-BOD5/m3-day, and 2) a nitrification rate of 0.427 kg-N/m3-day and a denitrification rate of 0.410 kg-N/m3-day each at a total ammonia loading of 0.434 kg-N/m3-day.