title: [Impact of Salinity on Leachate Treatment and N2O Releases from Semi-aerobic Aged-refuse Bioreactor].
abstract: Semi-aerobic Aged-refuse Bioreactor (SAARB) has a good effect on nitrogen removal in leachate, but a strong greenhouse gas (N2O) was generated during the nitrification and denitrification process. The effect of salinity (7-30 g x L(-1)) on the leachate treatment and the N2O production from SAARB system was investigated. Experimental results showed that salinity ranging from 7 to 30 g x L(-1) had no significant effect on COD removal, and the removal efficiency was always more than 85%. On the contrary, it had a strong influence on the removal of nitrogen. The removal efficiencies of NH4+ -N and TN decreased from 98. 23% and 91.48% at 7 g x L(-1) salt to 31.75% and 34.24% at 30 g x L(-1) salt, respectively. Moreover, there was significant nitrite (NO2- -N) accumulation in the presence of 30 g x L(-1) salt. Meanwhile, salinity had different inhibition strength on nitrification and denitrification bacteria, and the order of inhibition strength was as follows: nitrification bacteria > denitrification bacteria. In addition, the N2O production increased with salinity concentration, and the highest N2O accumulation (1397 microg +/- 369.88 microg) was observed with addition of 30 g x L(-1) salt, which accounted for 8.87%o of the total nitrogen removal. Meanwhile, it was 6-117 times higher in the presence of 30 g x L(-1) salt than that in low salinity conditions (7-20 g x L(-1)). And the peak time of the N2O production showed a delayed trend. These results indicated that salinity recirculation in leachate had a negative effect on the nitrogen removal and N2O production. Overall, salinity seemed to be a key parameter during leachate recirculation.
authors.forename: Wei-hua
authors.initials: WH
authors.lastname: Li
authors.forename: Ying-jie
authors.initials: YJ
authors.lastname: Sun
authors.forename: Zi-liang
authors.initials: ZL
authors.lastname: Liu
authors.forename: Qiang
authors.initials: Q
authors.lastname: Ma
authors.forename: Qiang
authors.initials: Q
authors.lastname: Yang
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D019149:Bioreactors; D058440:Denitrification; D058465:Nitrification; D009573:Nitrites / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry; D009609:Nitrous Oxide / Q000032:analysis*; D054712:Salinity
chemical_list: D009573:Nitrites; D009609:Nitrous Oxide; D009584:Nitrogen