Effect of long residence time and high temperature over anaerobic biodegradation of Scenedesmus microalgae grown in wastewater

JOURNAL OF ENVIRONMENTAL MANAGEMENT

卷:218

Article

Greses, S.¹  Zamorano-Lopez, N.¹  Borras, L.¹  Ferrer, J.²  Seco, A.¹  Aguado, D.² 

[1] Univ Valencia, CALAGUA Unidad Mixta UV UPV, Dept Engn Quim, Av Univ S-N, E-46100 Valencia, Spain

[2] Univ Politecn Valencia, CALAGUA Unidad Mixta UV UPV, Inst Univ Invest Engn Aigua & Medi Ambient IIAMA, Cami Vera S-N, E-46022 Valencia, Spain

关键词: Anaerobic digestion;    Biodegradability;    Membrane technology;    Microalgae;    Microbial analysis;    Scenedesmus spp;   

DOI  :  10.1016/j.jenvman.2018.04.086

来源: Elsevier

【 摘 要 】

Anaerobic digestion of indigenous Scenedesmus spp. microalgae was studied in continuous lab-scale anaerobic reactors at different temperatures (35 degrees C and 55 degrees C), and sludge retention time - SRT (50 and 70 days). Mesophilic digestion was performed in a continuous stirred-tank reactor (CSTR) and in an anaerobic membrane bioreactor (AnMBR). Mesophilic CSTR operated at 50 days SRT only achieved 11.9% of anaerobic biodegradability whereas in the AnMBR at 70 days SRT and 50 days HRT reached 39.5%, which is even higher than the biodegradability achieved in the thermophilic CSTR at 50 days SRT (30.4%). Microbial analysis revealed a high abundance of cellulose-degraders in both reactors, AnMBR (mainly composed of 9.4% Bacteroidetes, 10.1% Chloroflexi, 8.0% Firmicutes and 13.2% Thermotogae) and thermophilic CSTR (dominated by 23.8% Chloroflexi and 12.9% Firmicutes). However, higher microbial diversity was found in the AnMBR compared to the thermophilic CSTR which is related to the SRT. since high SRT promoted low growth-rate microorganisms, increasing the hydrolytic potential of the system. These results present the membrane technology as a promising approach to revalue microalgal biomass, suggesting that microalgae biodegradability and consequently the methane production could be improved operating at higher SRT. (C) 2018 Elsevier Ltd. All rights reserved.

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