Carrier modification and its application in continuous photo‐hydrogen production using anaerobic fluidized bed photo‐reactor

Abstract

Poor hydrogen production performance and low biomass limit the practical application of photo-fermentation. To improve the immobilization capability of bacteria and hydrogen production performance, activated carbon fibers (ACFs) were modified by acidic, alkaline, and neutral solutions. The modified ACFs were further used in the anaerobic fluidized bed photo-reactor (AFBPR) to explore its continuous operation characteristics. Results showed that among the three reagents, nitric acid was the most efficient for ACF modification, and the maximum yield and production rate of hydrogen increased between about 33.6% and 65.8% compared to the control. Furthermore, with the optimal influent glutamate concentration (10 mmol L À1 ) and light intensity (4000 lux), the AFBPR gave efficient and stable performance with hydrogen yield of 2.26 mol H 2 mol À1 acetate and hydrogen production rate of 25.8 mL L À1 h À1 . The results showed the potential of using the AFBPR with HNO 3 -modified ACF carriers for the large-scale production of bio-hydrogen.

A new lipid-rich microalga Scenedesmus sp. strain R-16 isolated using Nile red staining: effects of carbon and nitrogen sources and initial pH on the biomass and lipid production

“…Before analyzing with SEM, the surface of algal cells was coated with a gold layer by employing Sputter Coater (Hitachi E-1010, Japan). Further, the treated specimens were explored by a scanning electron microscope (Hitachi S-3400 N, Japan) as the methods described previously [ 46 ]. The biomass in dry weight (DW) and total lipid content were determined as the produces described previously [ 20 , 47 , 48 ].…”

Best mode for photo-fermentation hydrogen production: The semi-continuous operation

“…A novel optical fiber photo-bioreactor was designed to produce hydrogen by R. palustris WP3e5 using acetate as the sole carbon source [7], and the yield of hydrogen of 2.64 mol-H 2 / mol acetate and light conversion efficiency of 1.42% were attained. A designed anaerobic fluidized bed photo-reactor by Ren et al was used, the yield of hydrogen of 2.26 mol H 2 /mol acetate and rate of hydrogen production of 25.8 ml/l/h was obtained [11]. Cui et al designed a novel disk photo-bioreactor for hydrogen production, and yield of hydrogen and light conversion efficiency reached 2.68 mol-H 2 /mol acetate and 1.6%, respectively [8].…”

“…3) The culture mode also determined photo-hydrogen production performance. Up to date, the most of studies used batch culture for hydrogen production test [2,10], some study used continuous culture [11,13] and few report used semi-continuous [12,15] or fed-batch culture [14]. Batch culture did not obtained higher biomass due to the decline of cell.…”

Improved Nile red staining of Scenedesmus sp. by combining ultrasonic treatment and three-dimensional excitation emission matrix fluorescence spectroscopy

“…R-16 was cultured in BG11 medium as described previously [32]. After adjusting the pH to 7.0 using HCl (1 mol L −1 ) and NaOH (1 mol L −1 ), the medium was sterilized at 121°C for 15 min [33]. After inoculation, the cultures were incubated at 25 ± 1°C in a shaker at 130 rpm [34].…”