BioChem - DOS

The use of acidified palm oil mill effluent for thermophilic biomethane production by changing the hydraulic retention time in anaerobic sequencing batch reactor

International journal of hydrogen energy

Abd Nasir, Muhammad Azri; Jahim, Jamaliah Md; Abdul, Peer Mohamed; Silvamany, Hemavathi; Maaroff, Rizal Muzhafar; Mohammed Yunus, Mohammed Faisal

<P><B>Abstract</B></P> <P>The feasibility of thermophilic biomethane production from acidified palm oil mill effluent (POME) was assessed in a 5 L anaerobic sequencing batch reactor (ASBR). The effects of various hydraulic retention time (HRT) (10-1 d) on methane production performance and the stability of ASBR in treating acidified POME were evaluated herein. It was found that the highest methane productivity of 5.65 L CH<SUB>4</SUB>/L/d could be attained at HRT of 2 d. However, the removal of chemical oxygen demand (COD) and volatile fatty acid (VFA) at this HRT is rather low (65-62%) hence making it inefficient to operate at HRT 2 d since most of the contaminants remained in the liquid streams. Thus the most recommended HRT was 3 d with maximum methane productivity of 3.96 L CH<SUB>4</SUB>/L/d with corresponding methane yield of 260.3 L CH<SUB>4</SUB>/kgCOD<SUB>removed</SUB>. The COD removal efficiency at 3 d HRT was 71%, and the VFA consumption was more than 80%. The correlation of total VFA: total alkalinity (TVFA: TA) at HRT of 3 d was found to be 0.1. This recommended HRT of 3 is equally shorter than any previously reported application of POME as a substrate for thermophilic biomethane.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Low HRT (&le;3 d) and thermophilic temperature (55 &deg;C) boost the biomethane productivity. </LI> <LI> Yield of biomethane and waste removal efficiency declines at low HRT (<5 d). </LI> <LI> High probability of a shift in the methanogenic community at low HRT (<5 d). </LI> <LI> Optimum HRT of 3 d was suggested considering performance and stability of digester. </LI> <LI> Digester went out of control at HRT 1 due to overloading of substrate. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

2019

Elsevier

0360-3199

1879-3487

44

6

pp.3373-3381

10.1016/j.ijhydene.2018.06.149

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART94847911

HRT; Thermophilic; ASBR; Acidified POME; Biomethane