title: Disinhibition of the ammonium nitrogen in autothermal thermophilic aerobic digestion for sewage sludge by chemical precipitation.
abstract: Magnesium ammonium phosphate (MAP) precipitation was introduced to remove ammonium nitrogen (NH4(+)-N) in autothermal thermophilic aerobic digestion (ATAD) in this study by addition of MgCl2 · 6H2O and NaH2PO4 · 2H2O. The results showed that the lowest NH4(+)-N concentration was found in the D2 digester after 2nd day dosing treatment and 38.12% of VS removal efficiency was obtained after 15 days ATAD treatment. Sludge stabilization was achieved in the D2 digester 6 days earlier than the non-dosing digester when 8.7 g/L MgCl2 · 6H2O and 6.7 g/L NaH2PO4 · 2H2O were added into the digester. Furthermore, the highest VS removal efficiency of 40.03% was observed after 21 days digestion in D2 digesters. Therefore, MAP precipitation was an effective method for the ammonium nitrogen disinhibition when 8.7 g/L MgCl2 · 6H2O and 6.7 g/L NaH2PO4 · 2H2O were added into on the 2nd day after the digester startup.
authors.affiliation: School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Haiping
authors.initials: H
authors.lastname: Yuan
authors.affiliation: School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Changwen
authors.initials: C
authors.lastname: Xu
authors.affiliation: School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: nwzhu@sjtu.edu.cn.
authors.forename: Nanwen
authors.initials: N
authors.lastname: Zhu
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000332:Aerobiosis; D064751:Ammonium Compounds / Q000302:isolation & purification*; D001419:Bacteria / Q000378:metabolism; D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D011232:Chemical Precipitation; D006863:Hydrogen-Ion Concentration; D009584:Nitrogen / Q000302:isolation & purification*; D010100:Oxygen / Q000378:metabolism; D010758:Phosphorus / Q000302:isolation & purification; D012037:Refuse Disposal / Q000379:methods*; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology; D013696:Temperature; D014835:Volatilization
chemical_list: D064751:Ammonium Compounds; D012722:Sewage; D010758:Phosphorus; D000255:Adenosine Triphosphate; D009584:Nitrogen; D010100:Oxygen
keywords: Ammonium nitrogen disinhibition; Autothermal thermophilic aerobic digestion (ATAD); Magnesium ammonium phosphate (MAP) precipitation; Sewage sludge; Stabilization