Ni-Mg-Al Hydrotalcite for Improvement of Dark Fermentative Hydrogen Production

Ni-Mg-Al hydrotalcite (HT) was employed to test its potential to enhance biohydrogen production with various doses, from 83 to 417 mg/L. Experiments were carried out at 37 oC using heat-treated anaerobic sludge as inoculum and sucrose as synthetic wastewater in batch tests. X-ray diffraction (XRD) pattern and Fourier transform infrared (FTIR) spectrum were recorded to determine structure and functional groups of HT. As a result, addition of 250 mg/L Ni-Mg-Al HT showed the highest hydrogen yield of 3.37 ± 0.17 mol H2/mol sucrose, which improved the biohydrogen production by 80%. At the end of fermentation process, concentrations of metabolites, including lactic acid, acetic acid, and butyric acid were 160 mg/L, 4661 mg/L, and 5625 mg/L, respectively. Enhancement of biohydrogen production by addition of 250 mg/L Ni-Mg-Al HT can be attributed to basic property of HT, facilitation of magnesium in electron transfer process and suitable concentration of nickel as well.