Biohydrogen production from traditional Chinese medicine wastewater in anaerobic packed bed reactor system.

Three anaerobic packed bed reactors (APBR) packed with activated carbon, maifanite and tourmaline as support material were continuously operated for 165 days to generate hydrogen from traditional Chinese medicine wastewater at different organic loading rates (OLR) from 15.2 to 91.3 g COD L-1 d-1 by changes of hydraulic retention time (HRT) varying from 24 to 6 h. The best performance with hydrogen production rate (HPR) of 7.92 ± 0.27 mmol L-1 h-1 and hydrogen yield (HY) of 3.50 ± 0.09 mmol g-1 COD was achieved for the reactor with tourmaline at OLR of 60.8 g COD L-1 d-1 (HRT = 6 h), followed by activated carbon and maifanite. The main metabolic products for each reactor were found to be acetate and butyrate in the effluent with pH range of 5.6-6.4 and microbial analysis revealed that the dominant communities in all cultures were C. carboxidivoran and C. butyricum, responsible for acetate and butyrate production respectively.

Continuous hydrogen and methane production from the treatment of herbal medicines wastewater in the two-phase 'UASBH-ICM' system.

A two-phase anaerobic system comprised of upflow anaerobic sludge bed (UASB) reactor for hydrogen production and internal circulation reactor (IC) for methane production was proposed and investigated at laboratory scale and mesophilic temperature (35 °C). Hydrogen was efficiently produced from the UASB with the highest production rate of 3.00 ± 0.04 L · L-1 reactor · d-1 at optimum hydraulic retention time (HRT) of 6 h and in the IC, methane was also produced from residual organic matter and soluble metabolite products (SMP) with a production rate of 2.54 ± 0.04 L · L-1 reactor · d-1 at optimum HRT of 15 h. Finally, system HRT of 21 h was determined to be the optimum HRT at which energy conversion efficiency increased from 9.6 ± 0.1% (hydrogen only production) to 72.4 ± 2.5% (hydrogen and methane coproduction) and system chemical oxygen demand (COD) removal reached up to the high level of 90.1 ± 2.1%.

Co-production of hydrogen and methane from herbal medicine wastewater by a combined UASB system with immobilized sludge (H2 production) and UASB system with suspended sludge (CH4 production).

An upflow anaerobic sludge bed (UASB) system with sludge immobilized on granular activated carbon was developed for fermentative hydrogen production continuously from herbal medicine wastewater at various organic loading rates (8-40 g chemical oxygen demand (COD) L(-1) d(-1)). The maximum hydrogen production rate reached 10.0 (±0.17) mmol L(-1) hr(-1) at organic loading rate of 24 g COD L(-1) d(-1), which was 19.9% higher than that of suspended sludge system. The effluents of hydrogen fermentation were used for continuous methane production in the subsequent UASB system. At hydraulic retention time of 15 h, the maximum methane production rate of 5.49 (±0.03) mmol L(-1) hr(-1) was obtained. The total energy recovery rate by co-production of hydrogen and methane was evaluated to be 7.26 kJ L(-1) hr(-1).