The stability of aerobic granular sludge under low energy consumption: optimization of the granular size distribution by a novel internal component
To enhance the stability and pollutant removal performance of aerobic granular sludge (AGS), four groups of AGS reactors with mesh screens of different pore sizes (R1 is the control reactor; R2, R3, and R4 have pore sizes of 1.5, 2.5, and 3.5 mm, respectively) were established in this study. The res...
Saved in:
Published in | Environmental science water research & technology Vol. 7; no. 6; pp. 1125 - 1136 |
---|---|
Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Cambridge
Royal Society of Chemistry
03.06.2021
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | To enhance the stability and pollutant removal performance of aerobic granular sludge (AGS), four groups of AGS reactors with mesh screens of different pore sizes (R1 is the control reactor; R2, R3, and R4 have pore sizes of 1.5, 2.5, and 3.5 mm, respectively) were established in this study. The results showed that the granular sludge in the reactor with a 2.5 mm mesh screen (R3) has the highest mixed liquor suspended solids (MLSS) value of 8.2 ± 0.2 g L
−1
and the lowest sludge volume index (SVI
30
) value of 30 mL g
−1
. At the same time, the mature granular sludge in R3 had a compact structure and excellent total nitrogen (TN) removal performance (84.9 ± 1.2%), along with an optimal granule size distribution (span value of 96 ± 0.12). Analysis of the sludge microbial community showed that R3 has a higher enrichment of functional microorganisms, such as
Zoogloea
spp. (50.5%) and
Thauera
spp. (16.1%). This is beneficial for improving its intercellular adhesion and denitrification performance. The granule size distribution results indicated that R3 screened the growing granules with its appropriate mesh aperture in terms of optimizing hydraulic shear, thus inhibiting the growth of filamentous bacteria and keeping the granule size within the optimal range. This created a favorable niche for these fast-growing microorganisms, eventually forming granules with good stability and high denitrification efficiency.
An innovative and energy-saving reactor set-up can optimize the granule size distribution and achieve stable aerobic granular sludge. |
---|---|
Bibliography: | Electronic supplementary information (ESI) available. See DOI 10.1039/d1ew00060h |
ISSN: | 2053-1400 2053-1419 |
DOI: | 10.1039/d1ew00060h |