Improving Settleability and Enhancing Biological Phosphorus Removal through the Implementation of Hydrocyclones

Growth Progression of Oxygenic Photogranules and Its Impact on Bioactivity for Aeration-Free Wastewater Treatment

“…Thus, the intermittent provision of high-shear conditions may also limit the overgrowth of OPGs in bioreactors. Other approaches include the use of devices that enable the separation of biomass based on size, such as hydrocyclones, − which are already being used on an industrial scale . For this kind of selective biomass removal, however, we may need to consider the growth rates of photogranules and how they may affect the effectiveness of granulation, as the growth rates of photogranules are expected to be different depending on size.…”

Coupling physical selection with biological selection for the startup of a pilot-scale, continuous flow, aerobic granular sludge reactor without treatment interruption

“…If this more conventionally applied bioflocs-to-AGS transition setup were applied, the external physical selector would be the only driving force to transform flocculent sludge to AGS, and thus a much more radical biofloc washout type of short SRT would have to be employed ( Sun et al., 2019 ). Even with the sidestream hydrocyclone installation, only 5–7% of the RAS can be subjective to physical selection ( Avila et al., 2021 ; Partin, 2019 ; Regmi et al., 2022 ), leaving majority of the bioflocs and AGS unseparated in the RAS returned to the feast zone where bioflocs gain more growth advantage over AGS, which explains the slow startup period, e.g., one year, needed to observe sludge settleability improvement ( Ford et al., 2016 ; Kent et al., 2018 ; Roche et al., 2022 ; Welling et al., 2015 ; Wett et al., 2015 ).…”

“…This low strength selection pressure plus the high suspended solids content in RAS, e.g., 5000 mg L − 1 , compromised the physical selection efficiency of hydrocyclones for AGS ( Ford et al., 2016 ). As a result, a prolonged startup phase perhaps as long as a year was required to observe significant sludge settleability improvements in full-scale continuous flow reactors in which AGS formation is still a challenge ( Ford et al., 2016 ; Kent et al., 2018 ; Roche et al., 2022 ; Welling et al., 2015 ; Wett et al., 2015 ). For this reason, an alternative strategy should be developed to provide sufficient selection strength to promote successful continuous flow AGS formation while maintaining the startup treatment performance required for large full-scale applications.…”

Insights into function of hydrocyclone separator and modified volcanic rock coagulant on formation of aerobic granular sludge

“…The hydrocyclone separator is a common device for the separation of solid particles (Castilho & Medronho, 2000). At present, Indense™ (Avila et al, 2021), DEMON ® (Klein et al, 2012) and S-Select ® (Welling et al, 2015) were used to separate the activated sludge with different weights and sizes. Guo et al (2022) This study aims to test two methods to promote the formation of granular sludge.…”