| Title | Cascade systems to recover resources from sludge by the integration of pretreatments to fermentation-based anaerobic bioleaching process |
| Abstract | Future sustainable technological solutions need to balance the development of sludge as resource against the
paramount necessity to protect human health and environment. Nutrients, metals, embedded energy, and the
avoidance of sludge handling costs are important examples of recoverable assets. The virtuous shift to an efficient
resource recovery platform should integrate pretreatments with biological conversion processes to extract values
from complex waste streams as waste activated sludge. The aims of this study were: i. to assess the feasibility of
sludge pretreatments as ultrasounds to promote the release of metals and organics; ii. to explore the potential of
anaerobic microorganisms to leach out embedded resources from sludge through an enhanced hydrolysis/
acidification step. The study proved that the acid addition to the sonicated feedstocks promoted a significant
solubilization and acidification of the system during the feeding days. Crucial strategy was the inhibition of
methanogens by thermal treatment of the start-up inoculum that assured pH stability, high VFAs production, and
elements (As, Co and Se) solubilization. High throughput analysis of 16 S rRNA gene sequencing performed on
this system revealed the presence of a high abundance of reads affiliated with hydrolytic and fermentative
bacteria, in particular belonging to the phyla Bacteroidetes, Firmicutes, and Actinobacteria. The produced VFAs, fed
into a semi-pilot digester with a short HRT of 15 days, were successfully converted into methane thanks to the
dominant acetoclastic methanogenic population. Mass and energy balance for a full-scale scenario of this
innovative biorefinery platform is reported and compared to a conventional sludge treatment scenario |
| Source | Journal of Environmental Chemical Engineering 10 |
| Keywords | Waste activated sludgeUltrasoundsFermentationMetalsVFAs |
| Journal | Journal of Environmental Chemical Engineering |
| Editor | Elsevier B.V., , |
| Year | 2022 |
| Type | Articolo in rivista |
| DOI | 10.1016/j.jece.2022.107711 |
| Authors | Barbara Tonanzi, Agata Gallipoli, Andrea Gianico, Maria Cristina Annesini, Simona Crognale, Giuseppe Mininni, Simona Rossetti, Camilla Maria Braguglia |
| Text | 466553 2022 10.1016/j.jece.2022.107711 Waste activated sludge Ultrasounds Fermentation Metals VFAs Cascade systems to recover resources from sludge by the integration of pretreatments to fermentation based anaerobic bioleaching process Barbara Tonanzi, Agata Gallipoli, Andrea Gianico, Maria Cristina Annesini, Simona Crognale, Giuseppe Mininni, Simona Rossetti, Camilla Maria Braguglia Water Research Institute, National Research Council of Italy, CNR IRSA, Area della Ricerca RM1, Via Salaria km 29.300, 00015 Monterotondo, Rome, Italy Dipartimento di Ingegneria Chimica, Universita degli Studi di Roma La Sapienza , 00184 Rome, Italy Future sustainable technological solutions need to balance the development of sludge as resource against the paramount necessity to protect human health and environment. Nutrients, metals, embedded energy, and the avoidance of sludge handling costs are important examples of recoverable assets. The virtuous shift to an efficient resource recovery platform should integrate pretreatments with biological conversion processes to extract values from complex waste streams as waste activated sludge. The aims of this study were i. to assess the feasibility of sludge pretreatments as ultrasounds to promote the release of metals and organics; ii. to explore the potential of anaerobic microorganisms to leach out embedded resources from sludge through an enhanced hydrolysis/ acidification step. The study proved that the acid addition to the sonicated feedstocks promoted a significant solubilization and acidification of the system during the feeding days. Crucial strategy was the inhibition of methanogens by thermal treatment of the start up inoculum that assured pH stability, high VFAs production, and elements As, Co and Se solubilization. High throughput analysis of 16 S rRNA gene sequencing performed on this system revealed the presence of a high abundance of reads affiliated with hydrolytic and fermentative bacteria, in particular belonging to the phyla Bacteroidetes, Firmicutes, and Actinobacteria. The produced VFAs, fed into a semi pilot digester with a short HRT of 15 days, were successfully converted into methane thanks to the dominant acetoclastic methanogenic population. Mass and energy balance for a full scale scenario of this innovative biorefinery platform is reported and compared to a conventional sludge treatment scenario 10 Published version https //www.sciencedirect.com/science/article/pii/S221334372200584X via%3Dihub Cascade systems to recover resources from sludge by the integration of pretreatments to fermentation based anaerobic bioleaching process Manuscript 2022 Tonanzi et al Cascade JECE.pdf Articolo in rivista Elsevier B.V. 2213 3437 Journal of Environmental Chemical Engineering Journal of Environmental Chemical Engineering TONANZI BARBARA giuseppe.mininni MININNI GIUSEPPE simona.rossetti ROSSETTI SIMONA camillamaria.braguglia BRAGUGLIA CAMILLA MARIA andrea.gianico GIANICO ANDREA agata.gallipoli GALLIPOLI AGATA simona.crognale CROGNALE SIMONA |
