The influence of solid retention time on IFAS-MBR systems: Assessment of nitrous oxide emission

JOURNAL OF ENVIRONMENTAL MANAGEMENT

卷:203

Article

Mannina, Giorgio¹  Capodici, Marco¹  Cosenza, Alida¹  Laudicina, Vito Armando²  Di Trapani, Daniele¹ 

[1] Univ Palermo, Dipartimento Ingn Civile, Ambientale, Aerosp,Mat, Viale Sci,Ed 8, I-90128 Palermo, Italy

[2] Univ Palermo, Dipartimento Sci Agr & Forestali, Viale Sci,Ed 4, I-90128 Palermo, Italy

关键词: Nitrous oxide;    IFAS-MBR;    UCT;    Activated sludge;    Biofilm;    Emission factor;   

DOI  :  10.1016/j.jenvman.2017.08.011

来源: Elsevier

【 摘 要 】

The aim of the present study was to investigate the nitrous oxide (N2O) emissions from a moving bed based Integrated Fixed Film Activated Sludge (IFAS) - membrane bioreactor (MBR) pilot plant, designed according to the University of Cape Town (UCT) layout. The experimental campaign had a duration of 110 days and was characterized by three different sludge retention time (SRT) values (infinity, 30 d and 15 d). Results highlighted that N2O concentrations decreased when the biofilm concentrations increased within the aerobic reactor. Results have shown an increase of N2O with the decrease of SRT. Specifically, an increase of N2O-N emission factor occurred with the decrease of the SRT (0.13%, 0.21% and 0.76% of influent nitrogen for SRT = infinity, SRT = 30 d and SRT = 15 d, respectively). Moreover, the MBR tank resulted the key emission source (up to 70% of the total N2O emission during SRT = cc period) whereas the highest N2O production occurred in the anoxic reactor. Moreover, N2O concentrations measured in the permeate flow were not negligible, thus highlighting its potential detrimental contribution for the receiving water body. The role of each plant reactor as N2O-N producer/consumer varies with the SRT variation, indeed the aerobic reactor was a N2O consumer at SRT = infinity and a producer at SRT = 30 d. (C) 2017 Elsevier Ltd. All rights reserved.

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