title: Effect of dosing time on the ammonium nitrogen disinhibition 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. The dosing time of MgCl2 · 6H2O and NaH2PO4 · 2H2O will influence the removal efficiency of ammonium nitrogen greatly, and the time interval of 2nd, 7th, 12th day were chosen in ATAD process. The lowest NH4(+)-N concentration was found in the 2nd day dosing digester, and 38.37% of VS removal rate was obtained after 12 days digestion, which achieved stabilization 9 days earlier than the non-dosing digester. It revealed that removal of ammonium nitrogen could accelerate the sludge stabilization process. Meanwhile, 49.30% of VS removal rate was found in the 2nd day dosing digester in the 21st day, much higher than that in the non-dosing digester, the 7th day dosing digester, and the 12th day dosing digester, with the corresponding value of 38.37%, 38.38% and 37.04%, respectively.
authors.affiliation: School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China.
authors.forename: Changwen
authors.initials: C
authors.lastname: Xu
authors.forename: Haiping
authors.initials: H
authors.lastname: Yuan
authors.forename: Ziyang
authors.initials: Z
authors.lastname: Lou
authors.forename: Guofang
authors.initials: G
authors.lastname: Zhang
authors.forename: Junzhe
authors.initials: J
authors.lastname: Gong
authors.forename: Nanwen
authors.initials: N
authors.lastname: Zhu
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000332:Aerobiosis; D064751:Ammonium Compounds / Q000032:analysis*; D001419:Bacteria / Q000378:metabolism; D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D011232:Chemical Precipitation; D005232:Fatty Acids, Volatile / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D009584:Nitrogen / Q000032:analysis*; D012722:Sewage / Q000382:microbiology*; D013696:Temperature; D013997:Time Factors; D014835:Volatilization; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*
chemical_list: D064751:Ammonium Compounds; D005232:Fatty Acids, Volatile; D012722:Sewage; D000255:Adenosine Triphosphate; D009584:Nitrogen
keywords: Ammonium nitrogen disinhibition; Autothermal thermophilic aerobic digestion; Magnesium ammonium phosphate precipitation; Sewage sludge; Stabilization