Table 2 Summary of cross-sectional and longitudinal study of HfMBR biofilms during pulse AgNP exposure.

From: Digital Proxy of a Bio-Reactor (DIYBOT) combines sensor data and data analytics to improve greywater treatment and wastewater management systems

AgNP [mg/L]

H+/O2 fluxb

Biofilm Detachmentc

Treatment Capacity

Causal Correlationd

Microbial Diversity

1.0

Burst increase in flux followed by return to qSSa within 2 hours (Supp.)

Burst detachment followed by return to qSS within 2 hours (Fig. 3)

Metabolism and reactor pH/O2 burst change, followed by return to qSS within 2 hours (Fig. 4)

Proton transport has negative short-term impact on O2; decays within 2 hours (Figs. 7,8)

Taxa shifts for AgNP> 1.0 mg/L (Figs. 5,6)

2.0

Burst increase in flux followed by return to qSS within 2 hours (Fig. 2)

Burst detachment followed by return to qSS within 2 hours (Fig. 3)

Metabolism and reactor pH/O2 burst change, followed by return to qSS within 2 hours (Fig. 4)

pH has negative short term impact on O2; decays within 2 hours (Figs. 7,8)

Taxa shifts for AgNP> 1.0 mg/L (Figs. 5,6)

3.0

Burst increase in flux. Mean flux decreased over time, but did not return to qSS (Supp.)

Burst detachment. Mean values decreased over time, but did not return to qSS (Fig. 3)

Metabolism and pH/O2 burst change. Mean values did not return to qSS (Supp.)

O2 is a weak driver of pH (Figs. 7,8)

Taxa shifts for AgNP> 1.0 mg/L (Figs. 5,6)

  1. aqSS = quasi steady state, not different than mean levels prior to exposure (p < 0.01, α = 0.05). bProton efflux and oxygen influx measured at the surface of HfMBR biofilms using microelectrodes. cParticle detachment measured using coulter counter with constant fluid flow. dCausal correlation determined via analysis of phase space dynamics.
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