DOI: 10.36347/sjet.2018.v06i06.004

Pages: 203-211

Excessive ammonia pollution in the source river water of the largest municipal water treatment plant in Bangladesh is beyond the capacity of removal by a conventional treatment process. In order to reduce, primarily, the ammonia from the raw water before it enters into the main treatment chain a full-scale biological pre-treatment unit ‘Meteor’- a ‘ Moving Bed Biofilm Reactor’ was installed & put at the beginning of the conventional treatment chain. The reduction of ammonia was quite significant, on average 93% of the design value, while the reduction of COD was in a range from 46 to 76%. The Meteor was able to treat and nitrify the raw water and produce an effluent that respects the guarantee of ammonia < 4.0 mg NH3-N/L when the raw water ammonia concentration was < 15 mg NH3-N/L. The operating parameters necessary to achieve the desired goal was also noted. The study results would provide guidance on the probable use of a biological pre-treatment system for ammonia removal elsewhere.