Abstract |
Discussed is a pilot scale study for ammonia removal at Owosso, Michigan, involving a physical-chemical wastewater treatment system consisting of chemical coagulation (lime to pH 8.8 to 9.4) sedimentation, deep bed filtration, carbon adsorption, chlorination to oxidize ammonia, and carbon dechlorination to remove free chlorine and chloramines. Ammonia-nitrogen was removed to any desired level by the chlorination-dechlorination system. Complete removal would require a chlorine to ammonia feed ratio of 9 to 1. The dechlorination carbon removed free chlorine and also the chloramines formed at less-than-breakpoint operation. There is an initial ammonia-nitrogen breakthrough when using fresh dechlorination carbon which is attributed to acclimation rather than continuous leakage. An hypothesis describing chloramine removal is presented. |