Properties of phenol-removal aerobic granules during normal operation and shock loading

Abstract

The physical structure and activity of aerobic granules, and the succession of bacterial community within aerobic granules under constant operational conditions and shock loading were investigated in one sequencing batch reactor over ten months. While the maturation phase of the granulation process began on day 30, the structure of microbial community changed markedly until after three months of reactor operation under constant conditions with a loading rate of 1.5 g phenol L(-1) day(-1). A shock loading of 6.0 g phenol L(-1) day(-1) from days 182-192 led to divergence of bacterial community, an inhibition of the biomass activity, and a decrease in phenol removal rate in the reactor. However, phenol was still completely removed under this disturbance. After the shock loading, the mean sizes of aerobic granules increased, and the activity of the microbial population within the granules decreased, although there appeared highly resilient for the dominant bacterial community of aerobic granules which mainly included beta-Proteobacteria. Correlation analysis suggested that biomass concentration and biomass loading were significantly related to the community composition of aerobic granules during the whole operational period. The development of a relatively stable bacterial community in aerobic granules implied that those distinct dominant microbes in aerobic granules were favorably selected and proliferated under the operational conditions.

Partial nitritation and o-cresol removal with aerobic granular biomass in a continuous airlift reactor

“…The present findings are consistent with the studies demonstrating that nitrifying bacteria embedded in microbial granules were effectively protected against the inhibitory effect of phenolic compounds present in the wastewater (Liu et al, 2005;Jiang et al, 2010).…”

Phenol and nitrogen removal in microalgal–bacterial granular sequential batch reactors

“…14 Aerobic granules possess a higher tolerance to dangerous pollutants, broader pollutant degradation portfolio and higher settling rates than conventional activated sludge flocs. [15][16][17][18] The presence of different redox conditions inside the granules allows simultaneous nitrification-denitrification (SND) in granular SBRs. 16 Therefore, this technology represents a promising alternative to conventional methods for the simultaneous removal of phenolic and nitrogenous compounds from chemical industries wastewater.…”

“…Aerobic granules possess a higher tolerance to dangerous pollutants, broader pollutant degradation portfolio and higher settling rates than conventional activated sludge flocs 15‐18 . The presence of different redox conditions inside the granules allows simultaneous nitrification–denitrification (SND) in granular SBRs 16 .…”

Sequentially alternating pollutant scenarios of phenolic compounds in a continuous aerobic granular sludge reactor performing simultaneous partial nitritation and o-cresol biodegradation

“…To minimise these effects, aerobic granular sludge systems could be an alternative to overcome the activated sludge limitation when facing SAP events. Aerobic granular sludge has proven to be feasible, resistant and resilient to dynamic changes in wastewater compositions compared to activated sludge (Jiang et al, 2010;Maszenan et al, 2011;Jemaat et al, 2014). The granular sludge possesses a unique structure assembled by a consortium of microorganisms wherein various species perform different and specific roles in the biodegradation of contaminants during wastewater treatment (Beun et al, 1999).…”