title: Performance of double-layer biofilter packed with coal fly ash ceramic granules in treating highly polluted river water.
abstract: To improve trickling filters' denitrification efficiency, a biofilter with a trickling upper layer and a submerged lower layer was developed and applied in treating highly polluted river water. It was packed with porous coal fly ash ceramic granules. Its start-up characteristics, influence of hydraulic loading rates (HLR), carbon/nitrogen (C/N) ratio and filter depth on pollutants removal were investigated. The results indicated this biofilter was started quickly in 16 days with river sediment as inoculum. Alternating nitrification and denitrification were achieved when water flowed downwards. COD and nitrogen were mainly removed in the upper layer and the lower layer, respectively. With HLR of 4.0-5.0m(3)/(m(2)d), chemical oxygen demand (COD), ammonium (NH(4)(+)-N) and total nitrogen (TN) in the effluent were below 50, 5 and 15 mg/L, respectively. This biofilter removed more than 80% of COD, 85% of NH(4)(+)-N and 60% of TN with C/N ratios ranging from 6 to 10.
authors: College of Civil Engineering, Nanjing Forestry University, Nanjing 210037, China. zqjing@njfu.edu.cn
authors: Zhaoqian
authors: Z
authors: Jing
authors: Yu-You
authors: YY
authors: Li
authors: Shiwei
authors: S
authors: Cao
authors: Yuyu
authors: Y
authors: Liu
mesh_terms: D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D002244:Carbon / Q000032:analysis; D002516:Ceramics / Q000737:chemistry*; D060729:Coal Ash / Q000737:chemistry*; D005374:Filtration / Q000295:instrumentation*; D009584:Nitrogen / Q000032:analysis; D016062:Porosity; D000644:Quaternary Ammonium Compounds / Q000302:isolation & purification; D045483:Rivers / Q000737:chemistry*; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000295:instrumentation* / Q000379:methods* / Q000592:standards
chemical_list: D060729:Coal Ash; D000644:Quaternary Ammonium Compounds; D014874:Water Pollutants, Chemical; D002244:Carbon; D009584:Nitrogen