Assessing the impact of palmitic, myristic and lauric acids on hydrogen production from glucose fermentation by mixed anaerobic granular cultures

Energy recovery through biohydrogen production for sustainable anaerobic waste treatment: an overview

“…Nasr et al (2012) reported an 18.5% increase in the energy yield from a two-stage anaerobic digestion process over that from a single-stage process using thin stillage (a by-product of ethanol production process) as substrate. A similar process configuration has also been reported in mesophilic batch reactors (Saady et al, 2012a(Saady et al, , 2012b(Saady et al, , 2012c and resulted in a high H 2 yield of 3.1 mol mol -1 glucose. A similar process configuration has also been reported in mesophilic batch reactors (Saady et al, 2012a(Saady et al, , 2012b(Saady et al, , 2012c and resulted in a high H 2 yield of 3.1 mol mol -1 glucose.…”

“…(Luo et al, 2010;Mohan et al, 2008), freeze-thawing (Mohammadi et al, 2012), repeated-aeration (Ren et al, 2008), and load-shock (Luo et al, 2010;O-Thong et al, 2009). Many of these pretreatments such as treatment with acid and base (BenYi and JunXin, 2009;Luo et al, 2010), BESA , heat-shock (Kotay and Das et al, 2009), repeated-aeration (Ren et al, 2008), combinations of acid, heat and chemicals , and LCFAs (Saady et al, 2012a(Saady et al, , 2012b(Saady et al, , 2012c were reported to be 'the best' in comparison to other methods. The following sections present a review on the effectiveness and deficiencies of specific culture pretreatments concerning H 2 production.…”

“…In batch mixed culture, 2 g l -1 of linoleic (C18:2) and oleic (C18:1) acids increased H 2 yield from glucose fermentation (Saady et al, 2012a(Saady et al, , 2012b(Saady et al, , 2012cRay et al, 2009). They could be obtained from food processing wastewater such as from vegetable oil industry.…”

Effects of pre-treatment technologies on dark fermentative biohydrogen production: A review

“…Saady et al (2012) pre-treated anaerobic granular culture with palmitic, myristic and lauric acids and obtained higher H 2 yields for the inoculum pre-treated with palmitic acid owing to hydrogenotrophic methanogens inhibition. However, myristic and lauric acid pre-treatments resulted in lower H 2 yield relative to the control due to possible inhibition of HPB besides HCB (Saady et al, 2012). Despite the fact that several inhibitors have been investigated for suppressing methanogenic activities, most of them have not been studied for their potential to enhance biohydrogen production from DF processes.…”

“…Besides the aforementioned inhibitors, other chemicals that have been studied for suppressing methanogenic activities include 2-chloroethanesulfonate, 2-mercaptoethanesulfonate and lumazine , other long chain fatty acids like caprylic, capric, palmitic, lauric, myristic and oleic acids (Koster and Cramer, 1987;Saady et al, 2012), hydrocarbons like ethylene, cyclopentadiene, cycloheptatriene, benzene, toluene, isoprene, 1-hexine, ethane, methyl chloride, fluoroacetate and methyl fluoride (Schink, 1985;Chan and Parkin, 2000;Liu et al, 2011;Chidthaisong and Conrad, 2000;Valdez-Vazquez and Poggi-Varaldo, 2009) and hydroxymethylglutaryl-SCoA reductase inhibitors . Saady et al (2012) pre-treated anaerobic granular culture with palmitic, myristic and lauric acids and obtained higher H 2 yields for the inoculum pre-treated with palmitic acid owing to hydrogenotrophic methanogens inhibition.…”