| Title | Insights into the Anaerobic Hydrolysis Process for Extracting Embedded EPS and Metals from Activated Sludge |
| Abstract | The amount of sewage sludge generated from wastewater treatment plants globally is unavoidably increasing. In recent years, significant attention has been paid to the biorefinery concept based on the conversion of waste streams to high-value products, material, and energy by microorganisms. However, one of the most significant challenges in the field is the possibility of controlling the microorganisms' pathways in the anaerobic environment. This study investigated two different anaerobic fermentation tests carried out with real waste activated sludge at high organic loading rate (10 g COD L-1d-1) and short hydraulic retention time (HRT) to comprehensively understand whether this configuration enhances extracellular polymeric substance (EPS) and metal solubilisation. The quantity of EPS recovered increased over time, while the chemical oxygen demand to EPS ratio remained in the range 1.31-1.45. Slightly acidic conditions and sludge floc disintegration promoted EPS matrix disruption and release, combined with the solubilisation of organically bound toxic metals, such as As, Be, Cu, Ni, V, and Zn, thereby increasing the overall metal removal efficiency due to the action of hydrolytic microorganisms. Bacteroidetes, Firmicutes, and Chloroflexi were the most abundant phyla observed, indicating that the short HRT imposed on the systems favoured the hydrolytic and acidogenic activity of these taxa. |
| Source | Microorganisms |
| Keywords | anaerobic hydrolysisextracellular polymeric substanceswaste activated sludgetoxic metalsmicrobial communitieshigh throughput 16S rRNA gene sequencing |
| Journal | Microorganisms |
| Editor | Molecular Diversity Preservation International, Basel, |
| Year | 2021 |
| Type | Articolo in rivista |
| DOI | 10.3390/microorganisms9122523 |
| Authors | Barbara Tonanzi, Agata Gallipoli, Andrea Gianico, Maria Cristina Annesini, Camilla Maria Braguglia |
| Text | 460443 2021 10.3390/microorganisms9122523 anaerobic hydrolysis extracellular polymeric substances waste activated sludge toxic metals microbial communities high throughput 16S rRNA gene sequencing Insights into the Anaerobic Hydrolysis Process for Extracting Embedded EPS and Metals from Activated Sludge Barbara Tonanzi, Agata Gallipoli, Andrea Gianico, Maria Cristina Annesini, Camilla Maria Braguglia Water Research Institute, National Research Council of Italy, IRSA CNR, Area della Ricerca RM1, Via Salaria km 29.300, Monterotondo, 00015 Roma, Italy Dipartimento di Ingegneria Chimica, Universita degli Studi di Roma La Sapienza , 00184 Rome, Italy The amount of sewage sludge generated from wastewater treatment plants globally is unavoidably increasing. In recent years, significant attention has been paid to the biorefinery concept based on the conversion of waste streams to high value products, material, and energy by microorganisms. However, one of the most significant challenges in the field is the possibility of controlling the microorganisms pathways in the anaerobic environment. This study investigated two different anaerobic fermentation tests carried out with real waste activated sludge at high organic loading rate 10 g COD L 1d 1 and short hydraulic retention time HRT to comprehensively understand whether this configuration enhances extracellular polymeric substance EPS and metal solubilisation. The quantity of EPS recovered increased over time, while the chemical oxygen demand to EPS ratio remained in the range 1.31 1.45. Slightly acidic conditions and sludge floc disintegration promoted EPS matrix disruption and release, combined with the solubilisation of organically bound toxic metals, such as As, Be, Cu, Ni, V, and Zn, thereby increasing the overall metal removal efficiency due to the action of hydrolytic microorganisms. Bacteroidetes, Firmicutes, and Chloroflexi were the most abundant phyla observed, indicating that the short HRT imposed on the systems favoured the hydrolytic and acidogenic activity of these taxa. Published version https //www.mdpi.com/2076 2607/9/12/2523 Insights into the Anaerobic Hydrolysis Process for Extracting Embedded EPS and Metals from Activated Sludge Manuscript 2021 Tonanzi et al METALS microorganisms.pdf Articolo in rivista Molecular Diversity Preservation International 2076 2607 Microorganisms Microorganisms barbara.tonanzi TONANZI BARBARA camillamaria.braguglia BRAGUGLIA CAMILLA MARIA andrea.gianico GIANICO ANDREA agata.gallipoli GALLIPOLI AGATA |
