Hydrogen generation in photobiological process from dairy wastewater

Enhancing biological hydrogen production through complementary microbial metabolisms

“…On the individual basis, R. capsulatus could evolve up to 3.12 mol H 2 /mol acetate with molasses as feed [142] and R. sphaeroides has been able to produce 1.23 mol H 2 / mol hexose of wheat starch [143] and 0.26 mol/mol hexose from sugar refinery effluent [144] (Table 3). A comparison of the H 2 yielded by R. sphaeroides over a wide range of substrates revealed dairy waste water, primarily composed of sugars, to be the most effective with a yield of 3.62 L/L (3.66 mmol/L/h) in comparison to 2.24 L/L (2.72 mmol/L/h) from brewery waste water [145,146], and up to 13.9 L/L feed (0.4 mmol/L/h) from olive mill waste water [112,147e149]. A similar effect of different bacterial strains on H 2 production from a common feed (potato steam peels) was observed to vary from 1.3 with R. palustris, 2.76e2.88 with R. capsulatus and 1.68e2.40 mol/mol hexose with R. sphaeroides [140].…”

Photofermentative Hydrogen Production in Outdoor Conditions

“…They can use different C sources, preferably, volatile fatty acids (VFA) such as acetic, butyric, lactic and malic acid for hydrogen production and nitrogen sources such as glutamate and ammonium for growth [131]. Moreover, they can also use sugar containing wastes derived from various industries such as the tofu industry wastewater [129], olive mill wastewater [132], sugar refinery wastewater [133], dairy wastewater [134], palm oil mill wastewater [135] and ground wheat starch [136]. Effluents from dark fermentation have also been applied in several studies [54,55,66,106,[137][138][139].…”

Energy recovery from agro-industrial wastewaters through biohydrogen production: Kinetic evaluation and technological feasibility

“…Cassava starch processing WW could be an ideal raw material for the dark fermentation process, due its rich composition of carbohydrates, nutrients (N, P) and minerals (Fe, Zn, Mg) [5] and [21]. High content of easily degradable carbohydrates and soluble organic substances (5e50 g L À1 COD) in dairy WW can support bacterial growth [22] and [23] for hydrogen production. Citrus WW, obtained from orange peels processed for pectin production, has 17% of soluble sugars [24], being a rich source of carbohydrates.…”