Biological hydrogen production from olive mill wastewater with two-stage processes

• Published in: International journal of hydrogen energy Vol. 31; no. 11; pp. 1527 - 1535
• Main Authors: EROGLU, E, EROGLU, I, GUNDUZ, U, TURKER, L, YUCEL, M
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Oxford Elsevier Ltd 01-09-2006; Elsevier
• Subjects: Alternative fuels. Production and utilization; Applied sciences; Biological hydrogen production; Clay treatment; Coupled system; Dark fermentation; Energy; Exact sciences and technology; Fuels; Hydrogen; Olive mill wastewater; Photofermentation; Olive mill wastewater; Photofermentation; Clay treatment; Coupled system; Dark fermentation; Biological hydrogen production; Hydrogen; Rhodospirillaceae; Biomass; Fermentation; Waste water; Olive; Rhodospirillales; Rhodobacter sphaeroides; Bacteria; Pretreatment; Rhodospirillineae; Hydrogen production
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2006.06.020

In the present work two novel two-stage hydrogen production processes from olive mill wastewater (OMW) have been introduced. The first two-stage process involved dark-fermentation followed by a photofermentation process. Dark-fermentation by activated sludge cultures and photofermentation by
Rhodobacter sphaeroides O.U.001 were both performed in 55
ml glass vessels, under anaerobic conditions. In some cases of dark-fermentation, activated sludge was initially acclimatized to the OMW to provide the adaptation of microorganisms to the extreme conditions of OMW. The highest hydrogen production potential obtained was
29
l
H
2
/
l
OMW
after photofermentation with 50% (v/v) effluent of dark fermentation with activated sludge. Photofermentation with 50% (v/v) effluent of dark fermentation with acclimated activated sludge had the highest hydrogen production rate
(
0.008
l
l
-
1
h
-
1
)
.
The second two-stage process involved a clay treatment step followed by photofermentation by
R. sphaeroides O.U.001. Photofermentation with the effluent of the clay pretreatment process (4% (v/v)) gives the highest hydrogen production potential
(
35
l
H
2
/
l
OMW
)
, light conversion efficiency (0.42%) and COD conversion efficiency (52%).
It was concluded that both pretreatment processes enhanced the photofermentative hydrogen production process. Moreover, hydrogen could be produced with highly concentrated OMW. Two-stage processes developed in the present investigation have a high potential for solving the environmental problems caused by OMW.