title: On-site nutrient recovery and removal from source-separated urine by phosphorus precipitation and short-cut nitrification-denitrification.
abstract: Source separation and treatment of human urine have been recognized as a resource-efficient alternative to conventional urban drainage, not only reducing nutrient loads on municipal wastewater treatment plants, but recovering valuable resources from waste streams. In this work, on-site phosphorus (P) recovery from real urine was carried out by using the brine from a reverse osmosis process as the flush water for urine-diverting toilets and a P precipitant, while nitrogen (N) was removed via short-cut nitrification-denitrification (SCND) in a membrane bioreactor (MBR). More than 90% of P was recovered by mixing the urine with reverse osmosis brine (1:1, v/v) under the condition of pH > 9.0. The recovered precipitates contained 10-15% of P and can potentially be reused for phosphate fertilizer production. Stable SCND was achieved in a MBR, and 45% of N was removed with the organic compounds in urine as the electron donor for denitrification. Methanol addition significantly elevated denitrification, which in turn replenished the alkalinity required for nitrification. More than 99% of P, 90% of organics and 90% of N were removed in the combined precipitation and MBR process. Nitrosomonas was observed to be the predominant ammonium-oxidizing bacteria, while nitrite-oxidizing bacteria (NOB) were absent in the microbial communities as revealed by fluorescence in situ hybridization and pyrosequencing technique. High concentrations of free ammonia and nitrite acids, as well as low dissolved oxygen, are the prevailing factors to inhibit the growth of NOB, which allows for stable operation of SCND in the MBR.
authors.affiliation: Department of Municipal and Environmental Engineering, Beijing Key Laboratory of Aqueous Typical Pollutants Control and Water Quality Safeguard, Beijing Jiaotong University, Beijing 100044, China.
authors.forename: Song
authors.initials: S
authors.lastname: Yao
authors.affiliation: Department of Municipal and Environmental Engineering, Beijing Key Laboratory of Aqueous Typical Pollutants Control and Water Quality Safeguard, Beijing Jiaotong University, Beijing 100044, China.
authors.forename: Liping
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Municipal and Environmental Engineering, Beijing Key Laboratory of Aqueous Typical Pollutants Control and Water Quality Safeguard, Beijing Jiaotong University, Beijing 100044, China; Environmental Protection Research Institute of Light Industry, Beijing Academy of Science and Technology, Beijing, China.
authors.forename: Detian
authors.initials: D
authors.lastname: Guan
authors.affiliation: Environmental Protection Research Institute of Light Industry, Beijing Academy of Science and Technology, Beijing, China.
authors.forename: Zhongguo
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Municipal and Environmental Engineering, Beijing Key Laboratory of Aqueous Typical Pollutants Control and Water Quality Safeguard, Beijing Jiaotong University, Beijing 100044, China.
authors.forename: Xiujun
authors.initials: X
authors.lastname: Tian
authors.affiliation: Department of Municipal and Environmental Engineering, Beijing Key Laboratory of Aqueous Typical Pollutants Control and Water Quality Safeguard, Beijing Jiaotong University, Beijing 100044, China.
authors.forename: Aimin
authors.initials: A
authors.lastname: Wang
authors.affiliation: Department of Municipal and Environmental Engineering, Beijing Key Laboratory of Aqueous Typical Pollutants Control and Water Quality Safeguard, Beijing Jiaotong University, Beijing 100044, China.
authors.forename: Guotian
authors.initials: G
authors.lastname: Wang
authors.affiliation: School of Civil and Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710048, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Yao
authors.affiliation: School of Civil and Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710048, China.
authors.forename: Dangcong
authors.initials: D
authors.lastname: Peng
authors.affiliation: Department of Municipal and Environmental Engineering, Beijing Key Laboratory of Aqueous Typical Pollutants Control and Water Quality Safeguard, Beijing Jiaotong University, Beijing 100044, China. Electronic address: lijy@bjtu.edu.cn.
authors.forename: Jiuyi
authors.initials: J
authors.lastname: Li
mesh_terms: D000641:Ammonia / Q000032:analysis; D001419:Bacteria / Q000235:genetics / Q000378:metabolism; D019149:Bioreactors / Q000382:microbiology; D011232:Chemical Precipitation; D058440:Denitrification; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D058465:Nitrification; D009573:Nitrites / Q000032:analysis; D009584:Nitrogen / Q000378:metabolism; D010100:Oxygen / Q000032:analysis; D010758:Phosphorus / Q000737:chemistry*; D059027:Recycling / Q000379:methods; D012492:Salts / Q000737:chemistry*; D014556:Urine / Q000737:chemistry*
chemical_list: D009573:Nitrites; D012492:Salts; C017082:brine; D010758:Phosphorus; D000641:Ammonia; D009584:Nitrogen; D010100:Oxygen
keywords: Membrane bioreactor; Nitrogen removal; Phosphorus recovery; Reverse osmosis brine; Short-cut nitrification-denitrification; Source-separated urine