Biohydrogen from anaerobic treatment of brewery wastewaters: A preliminary study

Abstract

Hydrogen gas is considered the energy of the future because it is renewable, clean, and does not generate greenhouse gas emissions. Among the existing processes for producing hydrogen, it is found biological production from residual wastewater with a high content of carbohydrates treated with an anaerobic process. The utilization of wastewater for hydrogen production is considered an economical alternative because the raw material is abundant and easy to access. In this sense, the present study assessed the hydrogen production from the wastewater of the beer industry treated by Up-flow Anaerobic Sludge Blanket Reactors (UASB). Then, it was applied a thermal shock (90 °C/15 min) to the inoculum, with a previous dark fermentation treatment. The results revealed that with an organic volumetric load of 9.1 gDQO/L.D., pH of 5.5, and a hydraulic retention time (HRT) of 2 h, the maximum percentage of hydrogen gas was 21 % which corresponds to a yield of hydrogen of 6.50 mMolH2/l. According to the results was found that the initial compound of wastewater influenced the stability and continuity of hydrogen gas (H2). Finally, this study identified the uncommon presence of methane gas (CH4) with hydrogen gas, despite keeping pH values nearby to 5.5, and has applied a thermal shock to the inoculum.