Issue 2, 2021

Hydrodynamic granulation of oxygenic photogranules

Abstract

Oxygenic photogranules (OPGs), granular assemblages of phototrophic and chemotrophic microbes, offer a promising biotechnology for wastewater treatment with self-aerating potential. Currently, the seed OPG is produced under hydrostatic conditions with activated-sludge inoculum. We investigated the development of OPGs under hydrodynamic conditions employing batches with different light, shear, and inoculum conditions. The results demonstrated hydrodynamic granulation of OPGs from activated sludge, presenting opportunities for rapid (less than 8 days) and bulk development. From the matrix of conditions investigated, we found that granulation occurs only with some combinations of different magnitudes of these input energies. For example, ×4 dilute inoculum combined with low light supported granulation under the different shear conditions utilized. However, ×4 dilution inoculum with high light and high shear did not support granulation. This observed disparity in applied conditions suggests that OPG granulation ensues only with favorable interaction of variable induced energy pressures coupled with biological response selecting for spheroidal aggregates. Multi-regression analysis on temporal changes in the ratio of sludge volume index for 5 min to 30 min settling, a metric for granulation, confirmed the intercorrelation of these energy inputs on OPG granulation. This granulation scheme, dependent on goldilocks interaction of selection pressures, can potentially be extended to other granules applied in wastewater treatment.

Graphical abstract: Hydrodynamic granulation of oxygenic photogranules

Supplementary files

Article information

Article type
Paper
Submitted
26 Oct 2020
Accepted
27 Dec 2020
First published
29 Dec 2020

Environ. Sci.: Water Res. Technol., 2021,7, 427-440

Author version available

Hydrodynamic granulation of oxygenic photogranules

J. G. Gikonyo, A. A. Ansari, A. S. Abouhend, J. E. Tobiason and C. Park, Environ. Sci.: Water Res. Technol., 2021, 7, 427 DOI: 10.1039/D0EW00957A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements