Details

Autor(en) / Beteiligte

• Mills, Simon
• Trego, Anna Christine
• Ward, John
• Castilla-Archilla, Juan
• Hertel, Johannes
• Thiele, Ines
• Lens, Piet N.L.
• Ijaz, Umer Zeeshan
• Collins, Gavin

Titel

Methanogenic granule growth and development is a continual process characterized by distinct morphological features

Ist Teil von

• Journal of environmental management, 2021-05, Vol.286, p.112229-112229, Article 112229

Ort / Verlag

England: Elsevier Ltd

Erscheinungsjahr

2021

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• Up-flow anaerobic bioreactors are widely applied for high-rate digestion of industrial wastewaters and rely on formation, and retention, of methanogenic granules, comprising of dense, fast-settling, microbial aggregates (approx. 0.5–4.0 mm in diameter). Granule formation (granulation) mechanisms have been reasonably well hypothesized and documented. However, this study used laboratory-scale bioreactors, inoculated with size-separated granular sludge to follow new granule formation, maturation, disintegration and re-formation. Temporal size profiles, volatile solids content, settling velocity, and ultrastructure of granules were determined from each of four bioreactors inoculated only with small granules, four with only large granules, and four with a full complement of naturally-size-distributed granules. Constrained granule size profiles shifted toward the natural distribution, which was associated with maximal bioreactor performance. Distinct morphological features characterized different granule sizes and biofilm development stages, including ‘young’, ‘juvenile’, ‘mature’ and ‘old’. The findings offer opportunities toward optimizing management of high-rate, anaerobic digesters by shedding light on the rates of granule growth, the role of flocculent sludge in granulation and how shifting size distributions should be considered when setting upflow velocities. [Display omitted] •Granule development is a dynamic, continual process of breaking and re-forming.•Size profiles of constrained-size sludge shifted to an innate, natural distribution.•A full complement of granule sizes was required for optimal bioreactor performance.•Key morphological features were associated with stages of granule development.