Hydrogen Production and Performance of Anaerobic Fixed-Bed Reactors Using Three Support Arrangements From Cassava Starch Wastewater

Abstract

Fixed-bed reactors have been considered promise alternatives for hydrogen production due to their simple construction and increase in the biomass retention. The purpose of this study was to investigate the biological production of hydrogen in anaerobic fixed-bed reactors with cassava starch wastewater used as substrate. Different support materials and arrangements of fixed-bed were used to evaluate the biological production of hydrogen in anaerobic continuous fixed-bed reactors, with cassava starch wastewater as substrate -recycled low-density polyethylene scraps, in packed bed (R1), recycled low-density polyethylene cylinders, in ordained bed (R3) and bamboo stems, in vertical arrangement (R2 and R4). In R1 the initial pH was adjusted for 6.0, with hydraulic retention time (HRT) of 4 h and organic loading rate (OLR) of 9.5 g.L -1 .d -1 . In R2 the initial pH was maintained in 4.5, with HRT of 4 h and OLR of 9.5 g. -1 ) were verified in the reactors with bamboo stems. In R4, the increase of OLR and the reduction of the initial pH contributed to the increase of butanol concentration in 1.8 times, diminishing the VHPR in 41.68%, yield in 63.95% and H2 in 37.6%, and indicating that the effect of pH is more pronounced with the increase of OLR, leading to the solventogenesis.

Cassava Wastewater Treatment in Fixed-Bed Reactors: Organic Matter Removal and Biogas Production

“…The reactors behavior exhibited similar patterns, indicating that the biomass attachment was effective in both supports. Good performances have been attributed to bamboo due to its porosity (R1−41%), since pore size (0.001-1,000 µm) facilitates the biomass development and the maintenance of anaerobic conditions in the support (Chen et al, 2012), in addition to improving mass transfer rates (Torres et al, 2017). Therefore, in treatment systems where wastewater composition can vary considerably, as is the case of cassava starch wastewater where we FIGURE 3 | Volumetric biogas production rate and estimated methane production in the reactors R1 and R2.…”

“…Bamboo is a perennial herb, composed mainly of fibers (Feng et al, 2008) and widely distributed in several regions of the world, as Asia (Peng and She, 2014) and America. Andreani et al (2015) and Torres et al (2017) evaluated bamboo as a support material in upflow acidogenic anaerobic reactors, destined to biohydrogen production from cassava starch wastewater. The aforementioned authors obtained satisfactory results in the reactor with bamboo support when compared to reactors with low density polyethylene support.…”

BIOHYDROGEN PRODUCTION IN AnSBBR IN FED-BATCH FROM STARCH EFFLUENT: INFLUENCE OF ORGANIC LOAD

“…The volume of biogas produced daily was measured through a 3L Mariotte flask (Scoma et al, 2013) connected to the gas outlet, located in the upper part of the reactor and filled with water. In this system, the volume of liquid displaced corresponded to the volume of gas generated (Torres et al, 2017). The final volume was obtained after the correction for the normal conditions of temperature and pressure (NCTP) (Equation 1), where: Pr corresponds to atmospheric pressure (mmHg); Vr is the volume of gas at the test conditions (mL); Tr is the temperature at which the reactor was subjected (°C); PNCTP is the atmospheric pressure at NCTP (760 mmHg); VNCTP is the volume of gas in the NCTP (mL); TNCTP represents the temperature in the NCTP (273 K -0ºC).…”

Production of biogas using AnF2B reactor from cassava starch wastewater with consortium bacteria as biocatalyst

“…The factors that affect biogas production, among others: Organic Loading Rate (OLR), Hydraulic Retention Time (HRT), kind of bacterial, pH, temperature, and inhibitors [3,6,10,11]. While several wastewater treatment processes are used to produce biogas, including: Anaerobic Digestion, UASB, Fixed Bed Reactor (FBR), Horizontal Reactor, Anaerobic Baffled Reactor (ABR) [12][13][14][15][16].…”