Evaluation of feeding strategies in upflow anaerobic sludge bed reactor for hydrogenogenesis at psychrophilic temperature

Abstract

The present work evaluated the biohydrogen production from a 0.4 L upflow anaerobic sludge blanket reactor type (UASB) operating at psychrophilic temperature (21 ±2 °C) at different feeding strategies varying hydraulic retention times (HRT) and sucrose concentration in the feeding. First strategy (24h/31c) fed semi-continuously 31 gsucrose L-1 at 24 h HRT; second strategy (12h/19c) fed semi-continuously 19 gsucrose L-1 at 12 h HRT; third strategy (4h/8c) fed continuously 8.3 gsucrose L-1 at 4 h HRT. After 70 days of operation, the UASB accumulated 65.44 L H2. The average HY for the whole operation during the three strategies was 62.6 NmL H2 gsucrose-1 , and average hydrogen content was 69.04%. In general terms, the best operation strategy was 12h/19c since it presented good set of results, the best HY (70.6 NmL H2 gsucrose-1) and a comparable hydrogen production rate (2.6 L (L d)-1) to that obtained in 4h/8c strategy (3.17 L (L d)-1). The average gross energy potential rate from the 12h/19c strategy was 46.21 kJ (L d)-1 , whereas energy heating losses were circumvented due to operation at psychrophilic regime. Indeed, psychrophilic or room temperatures should be broadly regarded as an effective alternative towards net energy gains in biohydrogen production.

Batch biohydrogen production from dilute acid hydrolyzates of fruits-and-vegetables wastes and corn stover as co-substrates

“…Volatile fatty acids (i.e acetic acid, propionic acid, butyric acid) and solvent (ethanol) composition in the liquid phase were determined by using a gas chromatograph (Thermo Scientific Trace 1310, U.S.A) as described in our previous publication [22] .…”

“…Hydrogenogenic inoculum was obtained from an anaerobic digester fed with FVW at 30 days of hydraulic retention time, started-up according to the Poggi-Varaldo et al [21]. To inhibit methaneproducing microflora, the anaerobic sludge was heat-shock treated in boiling water at 96 °C for 2 h [22].…”

“…21.13 g L -1 ) according to the experimental design. The fermentation was supplemented with 0.4 mL of 200 fold concentrated mineral medium [22]. After inoculation, each bottle was flushed during 3 min with nitrogen to promote anaerobic conditions and sealed with a rubber stopper and aluminum 7 rings.…”

Biorefinery concept comprising acid hydrolysis, dark fermentation, and anaerobic digestion for co-processing of fruit and vegetable wastes and corn stover

“…The methanogenic anaerobic sludge was heat-treated to inhibit methane-producing microflora in water bath at 96° C for 2 h. The initial reducing sugars (RS) were adjusted to 13 g/L and the amount of substrate and inoculum were added according to the inoculum to substrate ratio (ISR) of 1.2 (VS basis). The fermentation volume was supplemented with 4 mL of 200 fold mineral medium previously reported by Rodríguez-Valderrama et al (2019). The medium was supplemented with nitrogen source (1 g NH4Cl/L) and buffer medium (3 g K2HPO4/L, 1.5 g KH2PO4/L).…”

Biohydrogen Production via Dark Fermentation with Pig Manure and Glucose Using pH‐Dependent Feeding

“…Previous studies stabilized the DF process by recycling the methanogenic effluent. This effluent has a pH of 7–8 and a carbonate buffer and therefore exhibits alkaline properties . Manure has similar properties and, in this study, the process was stabilized by using the liquid phase of separated pig manure (PM) for feeding the reactors.…”