Hydrogen production from glucose-containing wastewater using an anaerobic sequencing batch reactor: Effects of COD loading rate, nitrogen content, and organic acid composition

摘要

In this work, the process performance of an anaerobic sequencing batch reactor (ASBR) for the hydrogen production from glucose-containing wastewater was studied. The anaerobic sludge taken from a brewery wastewater-treating anaerobic unit was pretreated by boiling for 15 min before being added into the ASBR unit as the seeding sludge. The ASBR unit was operated at a temperature of 37 °C, a hydraulic reaction time (HRT) of 24 h, and different chemical oxygen demand (COD) loading rates from 10 to 50 kg m~(-3) d~(-1) without and with pH control at 5.5. The results showed that at the optimum COD loading rate of 40 kg m~(-3) d~(-1) and pH 5.5, the produced gas was found to contain 44% H2 and 56% CO2, and no methane in the produced gas was detected at all operating conditions. At these optimum conditions, the highest hydrogen yield was 1.46 mol H2/mol glucose consumed. Additionally, the main organic components in the liquid effluent were acetic and butyric acids. Under the optimum COD-to-nitrogen (COD:N) ratio of 100:2.4, the system with pH controlled at 5.5 gave the highest specific H2 production rate of 7.441 H2 l~(-1) d~(-1), corresponding to the highest butyric acid to acetic acid ratio.