Effect of Hydraulic Retention Time on Anaerobic Baffled Reactor Operation: Enhanced Biohydrogen Production and Enrichment of Hydrogen-producing Acetogens

Abstract

Biohydrogen production by fermentation has become a promising technology developed in the world. In this study, diluted normal molasses wastewater is used as the raw material, and biohydrogen production efficiency and operation characteristics of an anaerobic baffled reactor (ABR) are studied. The effect of hydraulic retention time (HRT) on biohydrogen production efficiency and operating characteristics of ABR is extensively discussed. Experimental results showed that methanogen residuals were still observed in the last three compartments under HRT of 24 h and COD(Chemical oxygen demand) concentration of 8000 mg/L. Meanwhile, the first three compartments presented an ethanol fermentation type. The characteristics of butyric acid fermentation in Compartment IV were also enhanced. The average removal efficiency of COD was reduced to 15.4%. The average rates of biohydrogen production and specific biohydrogen production were 12.85 and 360.22 L/kg COD, respectively. The extension of HRT was beneficial to enrich hydrogen-producing acetogens and could increase the production rate of biohydrogen by a factor of 1.65. However, with the decrease in the bioactivity of acidogenic fermentation bacteria, the biohydrogen production efficiency of ABR was significantly reduced when HRT was longer than 30 h. The specific biogas production rate decreased from 191 to 92 L/(kg MLVSS·d). The specific biohydrogen production rate also decreased from 24.34 to 2.7 L/(kg MLVSS·d).

Review of Anaerobic baffled reactor for treatment of industrial wastewater in Nigeria

“…The anaerobic baffled reactor (ABR) represents the third generation of anaerobic bioreactors, distinguished by its specific design incorporating a series of vertical baffles within the reactor [26]. Originating from Stanford University in 1983, McCarty and colleagues developed the ABR, conceptualizing it as a sequence of up-flow anaerobic sludge blanket reactors (UASBS), characterized by multiple compartments [8,27,28].…”

Characteristics of Biohydrogen Production and Performance of Hydrogen-Producing Acetogen by Increasing Normal Molasses Wastewater Proportion in Anaerobic Baffled Reactor

“…The amount of biohydrogen production was considerably affected due to the hydrogen consumption property of methanogens [24]. A relatively low hydrogen partial pressure was beneficial to the performance of hydrogen-producing acetogens, and the hydrogen-consuming homoacetogen and methanogens were generally the symbiotic bacteria with hydrogen-producing acetogens [25,26]. Therefore, the existence of homoacetogen and methanogens was not conducive to the enrichment of hydrogen-producing acetogens and subsequently limited the biohydrogen production capacity in the ABR.…”

Effect of Localized Temperature Difference on Hydrogen Fermentation

“…There are various factors, such as pH, temperature, substrate types and lactic acid contamination can affect the H 2 fermentation performance [13][14][15][16]. Among them, temperature is a critical operational factor, since it influences the microbial growth, enzymatic activity, and population dynamics [17,18].…”