title: The effect of aerated rock filter geometry on the rate of nitrogen removal from facultative pond effluents.
abstract: Rock filters are an established technology for polishing waste stabilization pond effluents. However, they rapidly become anoxic and consequently do not remove ammonium-nitrogen. Horizontal-flow aerated rock filters (HFARF), developed to permit nitrification and hence ammonium-N removal, were compared with a novel vertical-flow aerated rock filter (VFARF). There were no differences in the removals of BOD5, TSS and TKN, but the VFARF consistently produced effluents with lower ammonium-N concentrations (<0.3 mg N/L) than the HFARF (0.8-1.5 mg N/L) and higher nitrate-N concentrations (24-29 mg N/L vs. 17-24 mg N/L).
authors.affiliation: University Tun Hussein Onn Malaysia, 6400 Batu Pahat, Johor, Malaysia. rafidahh@uthm.edu.my
authors.forename: R
authors.initials: R
authors.lastname: Hamdan
authors.forename: D D
authors.initials: DD
authors.lastname: Mara
mesh_terms: D000388:Air; D005374:Filtration / Q000379:methods*; D009584:Nitrogen / Q000737:chemistry*; D010865:Pilot Projects; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical; D018508:Water Purification / Q000379:methods*
chemical_list: D000644:Quaternary Ammonium Compounds; D014874:Water Pollutants, Chemical; D009584:Nitrogen