When particles accumulate and miner

When particles accumulate and mineralize, there will be an increased release of bacteria substrate in the system resulting in heterotrophic bacteria growth and oxygen consumption which may out-compete the slow growing nitrifying autotrophic bacteria oxidizing toxic ammonia and nitrite in the biofilter (Chen et al.,2006; Michaud et al., 2006; Lackner et al., 2008; Pellegrin et al.,2009).