title: Simultaneous denitrification and denitrifying phosphorus removal in a full-scale anoxic-oxic process without internal recycle treating low strength wastewater.
abstract: Performance of a full-scale anoxic-oxic activated sludge treatment plant (4.0×10(5) m(3)/day for the first-stage project) was followed during a year. The plant performed well for the removal of carbon, nitrogen and phosphorus in the process of treating domestic wastewater within a temperature range of 10.8°C to 30.5°C. Mass balance calculations indicated that COD utilization mainly occurred in the anoxic phase, accounting for 88.2% of total COD removal. Ammonia nitrogen removal occurred 13.71% in the anoxic zones and 78.77% in the aerobic zones. The contribution of anoxic zones to total nitrogen (TN) removal was 57.41%. Results indicated that nitrogen elimination in the oxic tanks was mainly contributed by simultaneous nitrification and denitrification (SND). The reduction of phosphorus mainly took place in the oxic zones, 61.46% of the total removal. Denitrifying phosphorus removal was achieved biologically by 11.29%. Practical experience proved that adaptability to gradually changing temperature of the microbial populations was important to maintain the plant overall stability. Sudden changes in temperature did not cause paralysis of the system just lower removal efficiency, which could be explained by functional redundancy of microorganisms that may compensate the adverse effects of temperature changes to a certain degree. Anoxic-oxic process without internal recycling has great potential to treat low strength wastewater (i.e., TN<35 mg/L) as well as reducing operation costs.
authors.affiliation: State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. Electronic address: wangqibin188@163.com.
authors.forename: Qibin
authors.initials: Q
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Center for Eco-Environmental Research, Nanjing Hydraulic Research Institute, Nanjing 210029, China. Electronic address: qchen@rcees.ac.cn.
authors.forename: Qiuwen
authors.initials: Q
authors.lastname: Chen
mesh_terms: D058440:Denitrification; D009566:Nitrates / Q000302:isolation & purification / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism*; D010758:Phosphorus / Q000302:isolation & purification* / Q000378:metabolism; D059027:Recycling; D013696:Temperature; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification* / Q000378:metabolism; D018508:Water Purification / Q000379:methods*
chemical_list: D009566:Nitrates; D010100:Oxygen; D010758:Phosphorus; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Biological nutrient removal; Denitrifying phosphorus removal; Simultaneous nitrification and denitrification; Wastewater treatment