The influence of sodium on biohydrogen production from food waste by anaerobic fermentation

Abstract

Anaerobic fermentation of food waste for hydrogen production was performed in serum bottles with various linear alkylbenzene sulfonate (LAS) dosages (7.1-21.4 g/l) and sodium concentrations (5.03-28.7 g/l). LAS can effectively inhibit the activity of hydrogen-consuming bacteria, and the maximum hydrogen yield of 109.2 ml/g volatile solid (VS) was obtained at an LAS dosage of 14.3 g/l without added sodium. The feasible pH for hydrogen production is 5.0-6.0, and the process will slow down or stop when the pH is below 5.0.The hydrogen production potential increased when the sodium concentration increased in the range 5.03-14.41 g/l. The maximum hydrogen yield was 154.8 ml/g VS, and then the hydrogen production began to decrease when the sodium concentration increased further. A sodium chloride concentration of 20 g/l and higher will enhance the osmotic pressure and make bacteria inert. In the effl uent, acetic acid is the major by-product. The results indicated that the hydrogen production from the anaerobic fermentation of food waste could clearly be increased with the additives and a sodium concentration less than 20 g/l.

Improvement of biohydrogen production by Enterobacter cloacae IIT-BT 08 under regulated pH

“…While at above optimal levels the hydrogen producing capability is severely compromised due to its effect on the microbial enzyme activities such as dehydrogenase activity, alkaline phosphatase and ATP (Hao et al, 2006). This finding is compatible with Hao et al (2006) and Cao and Zhao (2009) who have reported the positive effect of sodium ion concentration on hydrogen production from sucrose using anaerobic hydrogen producing granular sludge. However, this finding is against the report of Alshiyab et al (2008) that sodium ions are totally detrimental to the hydrogen producing capacity of organisms.…”

Net energy gain from solid organic wastes by dark fermentation and its end products

“…The first observation is that, in several studies that had claimed high hydrogen yields at higher temperatures, the net energy gain is negative. The second observation is that, the net energy gain found in this study is higher than that estimated from the data reported in all the 16 literature studies, all of which had been conducted at temperatures greater than 35 C. This comparison confirms the premise of this study that net energy gain rather than [13] Food/sewage sludge 35 56.6 À0.08 Cui et al [14] Beer lees waste 35 53.0 0.91 Cao and Zhao [15] Food waste 36 145.5 1.05 Cai et al [16] Sewage sludge 36 16.6 À9.47 Xing et al [17] Dairy manure 36 27.5 À0.37 Fan et al [18] Beer lees waste 36 54.4 0.88 Zhang et al [19] Corn stalk waste 37 130.9 0.48 Lay et al [20] Municipal solid waste 37 2.9 0.00 Danko et al [21] Food waste 37 157.0 2.93 Fang et al [22] Rice slurry 37 346.0 1.20 Pattra et al [23] Sugarcane bagasse 37 44.3 0.68 Feng et al [24] Apple pomace 37 101.1 À0.45 Kim et al [25] Food waste 40 2.7 À0.04 Gilroyed et al [26] Feedlot cattle manure 52 65.0 À0.81 Yokoyama et al [27] Cow waste slurry 60 22.1 À7.80 Luo et al [28] Cassava stillage 60 50.4 À0.68…”

Biochemical Hydrogen Potential Tests Using Different Inocula

“…In this case, alternative metabolites such as lactate are produced instead of hydrogen [31,64]. In particular, Cao and Zhao [65] found an inhibitory threshold level of 14,410 mg/L. Calcium is a constituent of extracellular polysaccharides, which plays a key role in the formation of biofilms and thereby improves cell granulation and settleability [66].…”