High biohydrogen yield from fresh cassava waste pulps via gas dissolution in a dark fermentative environment
Aaron Jan Felix T. Balbin, Hazel A. Gonzales, Leonil Anthony M. Bornillo, John Harold A. Tagupa, Reymar H. Jaro, Alexander L. Ido, Renato O. Arazo
Abstract
The improper disposal of wastes like cassava waste pulps (CWP) in the environment could likely result in putrefaction stench, leachate contamination of water bodies, illnesses/diseases in local populations, and many other adverse effects. This study exploited the use of CWP for the possible production of valuable biofuel such as biohydrogen (bio-H2). Acid hydrolysis was used to prepare the CWP, whereas heat shock was used to prepare the cow dung inoculum. Pretreated organic wastes were used as substrates for dark fermentation, which considered the effects of pH and hydraulic retention duration on bio-H2 generation. The gas chromatography analysis showed 99.89% bio-H2 component of the total biogas produced through dark fermentation. The dissolution of the produced carbon monoxide and carbon dioxide in water enhanced bio-H2 production. At 6.09 pH and 83.24 h HRT, a kilogram of fresh CWP can produce 12.39 ± 0.8 L bio-H2. Overall, the current research has shown that underutilized CWP from starch-producing companies can be used to make sustainable biofuel, which can help to reduce fossil-fuel-related emissions.