Inhibition of biohydrogen production by ammonia

Effects of nitrate concentration on biological hydrogen production by mixed cultures

“…Among these nitrogen resources, ammonia nitrogen is widely used as a nitrogen resource under both batch and continuous conditions [23]. It has been shown that at an appropriate concentration range, ammonia nitrogen increases fermentative hydrogen production.…”

“…However, at a much higher concentration, it could inhibit fermentative hydrogen production because it could change the intracellular pH of hydrogen-producing bacteria, increase the maintenance energy requirement for hydrogen-producing bacteria, or inhibit specific enzymes related to fermentative hydrogen production [19][20][21][22][23][24]. The optimal ammonia concentration reported by Bisaillon et al was 0.01 g N/L [19], while Bo et al [13] and Salerno et al [23] reported 0.1 N/L and 7 g N/L, respectively. The possible reasons for this difference in optimal concentration were seed sludge, substrates, ranges of ammonia concentration, and so on.…”

Fermentative biohydrogen production: trends and perspectives

“…However, increasing the sulfate concentration to 3000 mg/l, at pH 5.5, raised the VHPR to 40% and 98.6% of residual sulfate concentration was found in the effluent, indicating that the acidic environment was not favorable to sulfate reducing bacteria and sulfate reduction did not occur (Lin and Chen 2006). A decrease of 40% on VHPR and hydrogen yield was observed at ammonia concentrations of 7.8 g N-NH 4 /l compared with the value obtained at 0.8 g N-NH 4 /l, which was the optimal ammonia concentration for hydrogen production (Salerno et al 2006).…”

“…Also, they found that magnesium, sodium, zinc and iron were important trace metals affecting VHPR due to the fact that these elements are needed by bacterial enzyme cofactors, transport processes and dehydrogenase. Recent studies reported the effect of sulfate and ammonia concentrations on VHPR in CSTR systems with sucrose and glucose as substrate (Lin and Chen 2006;Salerno et al 2006). Increasing sulfate concentration from 0 to 3000 mg/l, at pH 6.7, reduced VHPR and shifted the metabolic pathway from butyrate to ethanol fermentation due to the occurrence of sulfate reduction.…”

Produção de hidrogênio por fermentação por um novo isolado de <i>Clostridium beijerinckii</i>

“…A biomassa terrestre é rica em polissacarídeos cujos monômeros principais são a glicose e a xilose, a produção de hidrogênio a partir destes tem sido amplamente investigada (VRIJE et al, 2007;FANG e LIU, 2002;LIN e CHENG, 2006;PIERRA et al, 2014;SALERNO et al, 2006;TIEN ANH et al, 2012;. No entanto, a biomassa marinha como as algas é rica em polissacarídeos cujos monômeros principais são a glicose, galactose e a manose (WEI et al, 2013), apresentando um notável potencial para produção de hidrogênio (XIA et al, 2015).…”