| Title | Bio-based production of medium-chain carboxylic acids from food waste and sludge without chemical addition: The pivotal role of mix ratio and pretreatment |
| Abstract | Medium-chain carboxylates such as caproic acid, have a plethora of applications, ranging from food additives to
bioplastics, and can be produced via microbial chain elongation (CE), a process that can be more sustainable than
conventional production routes. During CE short fatty acids accept electrons from donors as lactate or ethanol
elongating into medium-chain carboxylates with higher economic value and easier recoverability. Nowadays,
waste activated sludge (WAS) and food waste (FW) are the most abundant waste steams generated in European
cities impacting dramatically on environment, society, and economic sectors. A novel sustainable biotechnology
is here proposed to produce marketable caproic acid from mixed WAS and FW with in-situ self-formed lactate
without buffering agents addition. Different mix ratios between WAS and FW, and thermal pretreatment stra-
tegies were compared by fermentation batch tests. The production of lactate as electron donor (ED), together
with acetate and butyrate, and hydrogen assured high production of caproate only in presence of thermal pre-
treated WAS, able to reduce the potential risk of lactate accumulation and drop in pH. The findings of this study
demonstrate that the initial soluble carboydrate/protein ratio significantly affected the pH of the fermentation
broth in the first hours of fermentation, and that only using FW and pretreated WAS mixed using a ratio of 60/40
in terms of volatile solids, CE pathway and lactate utilization as ED were promoted obtaining the highest per-
centage of caproate (about 21% of the total produced carboxylic acids; 2 gCOD/L). |
| Source | Journal of cleaner production 436 |
| Keywords | carboxylic acidsfood wastesludgebiorefinerycaproic acid |
| Journal | Journal of cleaner production |
| Editor | Butterworth-Heinemann,, Oxford, Regno Unito |
| Year | 2024 |
| Type | Articolo in rivista |
| DOI | 10.1016/j.jclepro.2024.140560 |
| Authors | Tonanzi, B., Gallipoli, A., Frugis, A., Gianico, A., Lazzazzara, M., Angelini, S., Cecchini, G., Braguglia, C.M. |
| Text | 491458 2024 10.1016/j.jclepro.2024.140560 carboxylic acids food waste sludge biorefinery caproic acid Bio based production of medium chain carboxylic acids from food waste and sludge without chemical addition The pivotal role of mix ratio and pretreatment Tonanzi, B., Gallipoli, A., Frugis, A., Gianico, A., Lazzazzara, M., Angelini, S., Cecchini, G., Braguglia, C.M. Water Research Institute, CNR IRSA, Area Della Ricerca RM1, Monterotondo, Rome, Italy Acea Engineering Laboratories Research Innovation S.p.A, Via Vitorchiano 165, Rome, Italy Medium chain carboxylates such as caproic acid, have a plethora of applications, ranging from food additives to bioplastics, and can be produced via microbial chain elongation CE , a process that can be more sustainable than conventional production routes. During CE short fatty acids accept electrons from donors as lactate or ethanol elongating into medium chain carboxylates with higher economic value and easier recoverability. Nowadays, waste activated sludge WAS and food waste FW are the most abundant waste steams generated in European cities impacting dramatically on environment, society, and economic sectors. A novel sustainable biotechnology is here proposed to produce marketable caproic acid from mixed WAS and FW with in situ self formed lactate without buffering agents addition. Different mix ratios between WAS and FW, and thermal pretreatment stra tegies were compared by fermentation batch tests. The production of lactate as electron donor ED , together with acetate and butyrate, and hydrogen assured high production of caproate only in presence of thermal pre treated WAS, able to reduce the potential risk of lactate accumulation and drop in pH. The findings of this study demonstrate that the initial soluble carboydrate/protein ratio significantly affected the pH of the fermentation broth in the first hours of fermentation, and that only using FW and pretreated WAS mixed using a ratio of 60/40 in terms of volatile solids, CE pathway and lactate utilization as ED were promoted obtaining the highest per centage of caproate about 21% of the total produced carboxylic acids; 2 gCOD/L . 436 Published version https //www.sciencedirect.com/science/article/pii/S0959652624000076 via%3Dihub#mmc1 01/01/2024 Manuscript Bio based production of medium chain carboxylic acids from food waste and sludge without chemical addition the pivotal role of mix ratio and pretreatment 2024 Tonanzi et al Bio based production JCLP.pdf Articolo in rivista Butterworth Heinemann, 0959 6526 Journal of cleaner production Journal of cleaner production J. clean. prod. Journal of cleaner production. camillamaria.braguglia BRAGUGLIA CAMILLA MARIA andrea.gianico GIANICO ANDREA agata.gallipoli GALLIPOLI AGATA ANGELINI STEFANIA barbara.tonanzi TONANZI BARBARA |
