Continuous hydrogen production from cassava starch processing wastewater by two-stage thermophilic dark fermentation and microbial electrolysis

• Published in: International journal of hydrogen energy Vol. 42; no. 45; pp. 27584 - 27592
• Main Authors: Khongkliang, Peerawat, Kongjan, Prawit, Utarapichat, Bussakorn, Reungsang, Alissara, O-Thong, Sompong
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 09.11.2017
• Subjects: Biohydrogen; Cassava starch processing wastewater; Microbial electrolysis; Thermophilic dark fermentation; Two-stage process; Two-stage process; Thermophilic dark fermentation; Biohydrogen; Cassava starch processing wastewater; Microbial electrolysis
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2017.06.145

Hydrogen production from cassava starch processing wastewater by two-stage thermophilic dark fermentation and microbial electrolysis was investigated. Single-chamber membrane-free microbial electrolysis cell with applied voltage of 0.6 V was optimum for hydrogen production with hydrogen yield of 245 ml H2 gCOD−1. Continuous microbial electrolysis reactor has a maximum hydrogen yield of 182 ml H2 gCOD−1 at HRT of 48 h with energy recovery efficiency of 217%. The continuous integrated two-stage dark fermentation and microbial electrolysis have hydrogen yield of 465 ml H2 gCOD−1 with 2 times hydrogen yield improving compared with a single stage and a maximum COD removal of 58% was achieved. Dominated bacteria at an anode of microbial electrolysis cell were exoelectrogens belong to Brevibacillus sp. Caloranaerobacter sp. and Geobacillus sp. Continuous two-stage thermophilic dark hydrogen fermentation and microbial electrolysis were efficient processes for hydrogen production from cassava starch processing wastewater. •Integrated two-stage dark fermentation and microbial electrolysis was investigated.•Applied voltage of 0.6 was optimum for microbial electrolysis cell.•Hydrogen yield of continuous single stage MEC was 182 ml gCOD−1.•Hydrogen yield of continuous two-stage fermentation and MEC was 465 ml gCOD−1.•Brevibacillus sp. Caloranaerobacter sp. and Geobacillus sp. were dominated in MEC.