Title: Comparative optimisation of biohythane production from starch wastewater by one-stage and two-stage anaerobic digestion

Authors: Chakkaphop Warrajareansri; Jaruwan Wongthanate

Addresses: Faculty of Environment and Resource Studies, Mahidol University, 999 Phutthamonthon 4 Road, Salaya, Phutthamonthon, Nakhon Pathom, 73170, Thailand ' Faculty of Environment and Resource Studies, Mahidol University, 999 Phutthamonthon 4 Road, Salaya, Phutthamonthon, Nakhon Pathom, 73170, Thailand

Abstract: Now, energy crisis was the problem in the world. This research was study the biohythane production for renewable energy. The experiment was optimised using starch by one-stage and two-stage anaerobic digestion in batch reactor. For two-stage, the optimal conditions of biohythane production were pH 7.0, thermophilic temperature, C/N ratio 30 for a first step (hydrogen yield 63.65 mL H₂/g COD) and pH 7.5, thermophilic temperature, C/N ratio 30 for a second step (methane yield 184.59 mL CH₄/g COD). Furthermore, one-stage was achieved at an initial pH 7.5 under thermophilic temperature and C/N ratio 30 (methane yield 206.47 mL CH₄/g COD). At optimal conditions, the maximum COD removal of two-stage (73.75%) was higher than that of one-stage (68.70%). Overall bioenergy recovery of two-stage was more generation than that of one-stage, including utilisation of organic matter at the same time.

Keywords: biohythane production; starch wastewater; pH; C/N ratio; one-stage anaerobic digestion; two-stage anaerobic digestion.

DOI: 10.1504/IJEWM.2021.114425

International Journal of Environment and Waste Management, 2021 Vol.27 No.3, pp.292 - 309

Received: 16 Sep 2018
Accepted: 30 Dec 2019
Published online: 21 Apr 2021 *

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