African Journal of
Biotechnology

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12481

Full Length Research Paper

Effect of retention time on biohydrogen production by microbial consortia immobilised in polydimethylsiloxane

Isnazunita Ismail1,2* Mohd Ali Hassan1 , Nor’Aini Abdul Rahman1 and Chen Sau Soon2
  1Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 Serdang Selangor, Malaysia. 2Environmental Technology and Research Centre, SIRIM Berhad, 40911 Shah Alam Selangor, Malaysia.
Email: [email protected]

  •  Accepted: 14 December 2010
  •  Published: 24 January 2011

Abstract

 

An investigation on biohydrogen production from palm oil mill effluent (POME) was conducted in a continuous stirred tank reactor seeded with polydimethyl-siloxane (PDMS) immobilised mixed cultures at adjusted retention time. The hydrogen-producing bacteria obtained from an anaerobic digester used for treating POME were acclimatised and immobilised in PDMS. The immobilised cultures were assessed for their effectiveness in generating hydrogen in a continuous system. In this study, the PDMS cultures were fed with raw POME at hydraulic retention times of 6, 4 and 2 days and operated at controlled pH and temperature of 5.5 and 55°C, respectively. At hydraulic retention time (HRT) 2 days, the average hydrogen production rate per unit volume of POME was 2.1 NL/L/d. Hydrogen constituted up to 43% of the total gas produced and methane was not detected throughout the 150 days of continuous operation. The soluble carbohydrate degradation efficiency was highest at 81.2% during HRT 4 days and the concentration of soluble metabolites produced, followed the order of acetic > butyric > ethanol > propionic acid. The microbial diversity of the immobilised consortia determined by denaturing gradient gel electrophoresis (DGGE) changed at different HRTs; with increasing dominant species phylogenetically related to Clostridaceae. 

 

Key words: Hydrogen fermentation, palm oil mill effluent, polydimethylsiloxane (PDMS), immobilisation.

Abbreviation

Abbreviations: GHG, Greenhouse gasesSMR, steam methane reformingPOMEpalm oil mill effluent; COD, chemical oxygen demandEVAethylene vinyl acetate copolymer; PMMA, polymethyl methaacrylate; PVA, polyvinyl alcohol; PDMS, polydimethylsiloxane; PCR-DGGE, polymerase chain reaction coupled with denaturing gradient gel electrophoresis; VSS, volatile suspended solid; HRT, hydraulic retention time; TSS, total suspended solidsVFA, volatile fatty acidsTCD, thermal conductivity detectorCPO, crude palm oil; PEO, polyethylene-octene; ASBR, anaerobic sequencing batch reactor.