| Title | Biomethanization of citrus waste: Effect of waste characteristics and of storage on treatability and evaluation of limonene degradation |
| Abstract | This study proposes the evaluation of the suitability of mesophilic anaerobic digestion as a simple technology for the treatment of the citrus waste produced by small -medium agro-industrial enterprises involved in the transformation of Citrus fruits. Two different stocks of citrus peel waste were used (i.e., fresh and stored citrus peel waste), to evaluate the influence of waste composition (variability in the type of processed Citrus fruits) and of storage (potentially necessary to operate the anaerobic digester continuously over the whole year due to the seasonality of the production) on anaerobic degradation treatability. A thorough characterization of the two waste types has been performed, showing that the fresh one has a higher solid and organic content, and that, in spite of the similar values of oil fraction amounts, the two stocks are significantly different in the composition of essential oils (43% of limonene and 34% of linalyl acetate in the fresh citrus waste and 20% of limonene and 74% of linalyl acetate in the stored citrus waste). Contrarily to what observed in previous studies, anaerobic digestion was successful and no reactor acidification occurred. No inhibition by limonene and linalyl acetate even at the maximum applied organic load value (i.e., 2.72 gCOD(waste)/gVS(inoculum)) was observed in the treatment of the stored waste, with limonene and linalyl acetate concentrations of 104 mg/1 and 385 mg/1, respectively. On the contrary, some inhibition was detected with fresh citrus peel waste when the organic load increased from 2.21 to 2.88 gCOD(waste)/gVS(inocuium), ascribable to limonene at initial concentration higher than 150 mg/I. A good conversion into methane was observed with fresh peel waste, up to 0.33lCH(4)/gCOD(removed) at the highest organic load, very close to the maximum theoretical value of 0.35 lCH(4)/gCOD(removed), while a lower efficiency was achieved with stored peel waste, with a reduction down to 0.24 lCH(4)/gCOD(removed) at the highest organic load. (C) 2018 Elsevier Ltd. All rights reserved. |
| Source | Journal of environmental management 215, pp. 366–376 |
| Keywords | Citrus peel wasteAnaerobic digestionLimonene inhibitionLinalyl acetateStorage |
| Journal | Journal of environmental management |
| Editor | Academic Press., New York, Regno Unito |
| Year | 2018 |
| Type | Articolo in rivista |
| DOI | 10.1016/j.jenvman.2018.03.057 |
| Authors | Lotito, Adriana Maria; De Sanctis, Marco; Pastore, Carlo; Di Iaconi, Claudio |
| Text | 397477 2018 10.1016/j.jenvman.2018.03.057 ISI Web of Science WOS 000430784700036 Scopus 2 s2.0 85044474897 Citrus peel waste Anaerobic digestion Limonene inhibition Linalyl acetate Storage Biomethanization of citrus waste Effect of waste characteristics and of storage on treatability and evaluation of limonene degradation Lotito, Adriana Maria; De Sanctis, Marco; Pastore, Carlo; Di Iaconi, Claudio Water Research Institute, National Research Council, viale De Blasio 5, Bari, 70132, Italy; Regione Puglia, Dipartimento Mobilita, Qualita Urbana, Opere Pubbliche, Ecologia e Paessaggio, via Gentile 52, Bari, 70100, Italy This study proposes the evaluation of the suitability of mesophilic anaerobic digestion as a simple technology for the treatment of the citrus waste produced by small medium agro industrial enterprises involved in the transformation of Citrus fruits. Two different stocks of citrus peel waste were used i.e., fresh and stored citrus peel waste , to evaluate the influence of waste composition variability in the type of processed Citrus fruits and of storage potentially necessary to operate the anaerobic digester continuously over the whole year due to the seasonality of the production on anaerobic degradation treatability. A thorough characterization of the two waste types has been performed, showing that the fresh one has a higher solid and organic content, and that, in spite of the similar values of oil fraction amounts, the two stocks are significantly different in the composition of essential oils 43% of limonene and 34% of linalyl acetate in the fresh citrus waste and 20% of limonene and 74% of linalyl acetate in the stored citrus waste . Contrarily to what observed in previous studies, anaerobic digestion was successful and no reactor acidification occurred. No inhibition by limonene and linalyl acetate even at the maximum applied organic load value i.e., 2.72 gCOD waste /gVS inoculum was observed in the treatment of the stored waste, with limonene and linalyl acetate concentrations of 104 mg/1 and 385 mg/1, respectively. On the contrary, some inhibition was detected with fresh citrus peel waste when the organic load increased from 2.21 to 2.88 gCOD waste /gVS inocuium , ascribable to limonene at initial concentration higher than 150 mg/I. A good conversion into methane was observed with fresh peel waste, up to 0.33lCH 4 /gCOD removed at the highest organic load, very close to the maximum theoretical value of 0.35 lCH 4 /gCOD removed , while a lower efficiency was achieved with stored peel waste, with a reduction down to 0.24 lCH 4 /gCOD removed at the highest organic load. C 2018 Elsevier Ltd. All rights reserved. 215 Published version https //www.sciencedirect.com/science/article/pii/S0301479718302901 via%3Dihub Lotito et al. 2018 Versione pubblicata dell articolo Biomethanization of citrus waste_ Effect of waste characteristics and of storage on treatability and evaluation of limonene degradation.pdf Articolo in rivista Academic Press. 0301 4797 Journal of environmental management Journal of environmental management J. environ. manag. claudio.diiaconi DI IACONI CLAUDIO marco.desanctis DE SANCTIS MARCO carlo.pastore PASTORE CARLO |
