ABSTRACT
The study explored the spent wash valorisation into value added biobased products viz. volatile fatty acids (VFAs), biohydrogen (bio-H2), methane (CH4) and biohythane (bio-H-CNG) based on eight selected parameters employing design of experiment (DOE) approach. Selectively enriched biocatalyst showed marked influence on the production of acidogenic products (bio-H2 and VFA) while untreated inoculum resulted in higher CH4 and bio-H-CNG generation. CaCO3 showed potential for butyric acid (HBu) production while Na2CO3 specifically yielded higher acetic acid (HAc) when supplemented as buffering agents. Higher degree of acidification (DOA; 49.8%) was observed at lower organic load (OL; 30 g/L). Biogas production and profile was influenced by OL, enrichment of biocatalyst and supplemented buffering agent. Higher OL related to higher bioproduct production, while yields of the respective products were higher at lower OL.
