as cow dung, compost, chicken manure compost, and river sludge, sewage sludge at
optimum conditions (pH 5.5 and 45
C) produced a higher yield (319 mL H 2 /g
COD) [199].
4.1.2 Industrial Wastewater Sludge
O-Thong et al. [177] used anaerobic sludge from palm oil mill effluent (POME)
treatment plant as a source of inocula for the conversion of POME to H 2 . They
reported a maximum of 4820 mL H 2 /L POME (243 mL H 2 /g sugar) with a total
sugar consumption and chemical oxygen demand (COD) removal efficiency of
98.7% and 46%, respectively. Anaerobic sludge treating palm oil mill effluent
(POME) has been used as inoculum to convert POME to bioH 2 [177] and yielded
4.8 LH 2 /L POME (H 2 yield of 243 mL H 2 /g sugar) at initial pH 5.5 and 60
C.
Inocula derived from industrial waste such as soybean meal [25, 67, 211] and
cassava treating sludge [212] have been used in several studies.
4.1.3 Compost
Compost has been used to generate inoculum for H 2 production in dark fermentation
of several wastes such as food waste [213], carbohydrate, protein, and fat-rich
organic waste [113]. Ueno et al. [29] used compost to ferment sugary wastewater
and reported a yield of 2.52 mol H 2 /mol hexose in thermophilic operation.
4.1.4 Animal Dung
Cow manure has frequently been used, after a pretreatment, to serve as inoculum for
H 2 production during dark fermentation. Cow and cattle manure contains relatively
less methanogens compared to anaerobic sludge from municipal and industrial
wastewater treatment plants [214]. Therefore, cow manure requires less intensive
pretreatment (shorter time of heat shock treatment, smaller dosages of methanogen
inhibitors, and shorter duration of acid/base treatment). Song et al. [145] used
microwave pretreated cow dung as inoculum to ferment corn stalk and produce
hydrogen. Radjaram and Saravanane [215] investigated the start-up of a UASB
reactor to ferment municipal sewage sludge to produce H 2 , using cow dung as an
inoculum. Fangkum and Reungsang [216] reported a yield of 2.56 mol H 2 /mol sugar
from glucose/xylose using heat-treated elephant dung as inoculum for dark anaerobic fermentation. Xing et al. [202] used dairy manure as inoculum (infraredpretreated for 2 h) and substrate (pretreated with boiling in 0.2% HCl for 30 min)
for dark fermentation and reported a yield 31.5 mL H 2 /g VS. Vijayaraghavan et al.
[17] reported that cow dung successfully digested palm oil mill effluent and produced 2.03 mol H 2 /mol hexose.
8 Biohydrogen of Industrial Waste
349
optimum conditions (pH 5.5 and 45
C) produced a higher yield (319 mL H 2 /g
COD) [199].
4.1.2 Industrial Wastewater Sludge
O-Thong et al. [177] used anaerobic sludge from palm oil mill effluent (POME)
treatment plant as a source of inocula for the conversion of POME to H 2 . They
reported a maximum of 4820 mL H 2 /L POME (243 mL H 2 /g sugar) with a total
sugar consumption and chemical oxygen demand (COD) removal efficiency of
98.7% and 46%, respectively. Anaerobic sludge treating palm oil mill effluent
(POME) has been used as inoculum to convert POME to bioH 2 [177] and yielded
4.8 LH 2 /L POME (H 2 yield of 243 mL H 2 /g sugar) at initial pH 5.5 and 60
C.
Inocula derived from industrial waste such as soybean meal [25, 67, 211] and
cassava treating sludge [212] have been used in several studies.
4.1.3 Compost
Compost has been used to generate inoculum for H 2 production in dark fermentation
of several wastes such as food waste [213], carbohydrate, protein, and fat-rich
organic waste [113]. Ueno et al. [29] used compost to ferment sugary wastewater
and reported a yield of 2.52 mol H 2 /mol hexose in thermophilic operation.
4.1.4 Animal Dung
Cow manure has frequently been used, after a pretreatment, to serve as inoculum for
H 2 production during dark fermentation. Cow and cattle manure contains relatively
less methanogens compared to anaerobic sludge from municipal and industrial
wastewater treatment plants [214]. Therefore, cow manure requires less intensive
pretreatment (shorter time of heat shock treatment, smaller dosages of methanogen
inhibitors, and shorter duration of acid/base treatment). Song et al. [145] used
microwave pretreated cow dung as inoculum to ferment corn stalk and produce
hydrogen. Radjaram and Saravanane [215] investigated the start-up of a UASB
reactor to ferment municipal sewage sludge to produce H 2 , using cow dung as an
inoculum. Fangkum and Reungsang [216] reported a yield of 2.56 mol H 2 /mol sugar
from glucose/xylose using heat-treated elephant dung as inoculum for dark anaerobic fermentation. Xing et al. [202] used dairy manure as inoculum (infraredpretreated for 2 h) and substrate (pretreated with boiling in 0.2% HCl for 30 min)
for dark fermentation and reported a yield 31.5 mL H 2 /g VS. Vijayaraghavan et al.
[17] reported that cow dung successfully digested palm oil mill effluent and produced 2.03 mol H 2 /mol hexose.
8 Biohydrogen of Industrial Waste
349