title: Removal and recovery of N, P and K from urine via ammonia stripping and precipitations of struvite and struvite-K.
abstract: This study investigated the recovery of N, P and K from source-separated urine in laboratory-scale combined processes of air stripping and precipitation. Two operation scenarios were carried out to recover N/P (named partial scenario) and N/P/K (named complete scenario). Most of the nutrients were recovered (>70%) by optimising the operation parameters including the increase of air flow rate and more dosages of the sources of Mg and P. Absorbent rich in ammonium sulphate and solid precipitates including struvite, struvite-K, and struvite-Na was produced. The simultaneous recovery of P and K was the key process to determine the substance input. The ratio of substance input to nutrient recovered (P2O5and K2O) was 4.14 in the partial scenario, whereas it increased to 10.61 in the complete scenario. The inevitable co-precipitation of struvite-Na mainly responded for the lower economic efficiency of the complete scenario.
authors.affiliation: Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China E-mail: xukangning@bjfu.edu.cn.
authors.forename: Kangning
authors.initials: K
authors.lastname: Xu
authors.affiliation: School of Environment, Tsinghua University, Beijing 100084, China.
authors.forename: Chi
authors.initials: C
authors.lastname: Zhang
authors.affiliation: School of Environment, Tsinghua University, Beijing 100084, China.
authors.forename: Jiyun
authors.initials: J
authors.lastname: Li
authors.affiliation: Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China E-mail: xukangning@bjfu.edu.cn.
authors.forename: Xiang
authors.initials: X
authors.lastname: Cheng
authors.affiliation: School of Environment, Tsinghua University, Beijing 100084, China.
authors.forename: Chengwen
authors.initials: C
authors.lastname: Wang
mesh_terms: D000641:Ammonia; D006801:Humans; D009584:Nitrogen / Q000737:chemistry*; D010710:Phosphates; D011188:Potassium / Q000737:chemistry*; D000069877:Struvite; D014556:Urine / Q000737:chemistry*; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical
chemical_list: D010710:Phosphates; D014874:Water Pollutants, Chemical; D000641:Ammonia; D000069877:Struvite; D009584:Nitrogen; D011188:Potassium