Abstract

An expanded unified model for the biomass fractions, soluble-organic fractions, and oxygen-uptake rates considering extracellular polymeric substances (EPS), intracellular storage products (XSTO), and predators for activated sludge is used to study the impacts of predators on biomass components and oxygen uptake. The new model is applied to evaluate how predation affects the oxygen-uptake rate (OUR) and the different forms of biomass: active bacteria (XH), XEPS, and XSTO, under dynamic feast-and-famine and continuous conditions. For the dynamic conditions of a sequencing batch reactor (SBR), eliminating predators from the model increases XH and XEPS fractions significantly, and this causes the substantial increases in OUR and MLVSS once the famine period begins. An analysis of how the OUR is distributed among the several respiration processes shows that the predation of XH is the most significant oxygen utilization rate process in the system under famine conditions of an SBR. Application of the model to simulate the long-term operation of an SBR indicates that predators reach their maximum fraction in the MLVSS (∼4% of MLVSS) at a solids retention time of about 13 days, but they are washed out at a solids retention time less than ∼3 days. Simulation for a continuous system indicates that predators take more time (about 800 h) to reach steady state and reach their maximum fraction (∼5.5%) at an SRT of ∼14 days. Comparison of SBR and continuous systems reveals that the predators have greater impact in the continuous system because the permanent near-famine condition accentuates predation processes.

Original languageEnglish (US)
Pages (from-to)4616-4622
Number of pages7
JournalWater Research
Volume44
Issue number15
DOIs
StatePublished - Aug 2010

Fingerprint

Batch reactors
Biomass
famine
predator
oxygen
Oxygen
biomass
predation
activated sludge
evaluation
reactor
Bacteria
respiration
rate
bacterium
simulation

ASJC Scopus subject areas

  • Water Science and Technology
  • Waste Management and Disposal
  • Pollution
  • Ecological Modeling

Cite this

Evaluation on the impacts of predators on biomass components and oxygen uptake in sequencing batch reactor and continuous systems. / Ni, Bing Jie; Rittmann, Bruce; Yu, Han Qing.

In: Water Research, Vol. 44, No. 15, 08.2010, p. 4616-4622.

Research output: Contribution to journalArticle

@article{1783981f812d489c9945b40c51b77c61,
title = "Evaluation on the impacts of predators on biomass components and oxygen uptake in sequencing batch reactor and continuous systems",
abstract = "An expanded unified model for the biomass fractions, soluble-organic fractions, and oxygen-uptake rates considering extracellular polymeric substances (EPS), intracellular storage products (XSTO), and predators for activated sludge is used to study the impacts of predators on biomass components and oxygen uptake. The new model is applied to evaluate how predation affects the oxygen-uptake rate (OUR) and the different forms of biomass: active bacteria (XH), XEPS, and XSTO, under dynamic feast-and-famine and continuous conditions. For the dynamic conditions of a sequencing batch reactor (SBR), eliminating predators from the model increases XH and XEPS fractions significantly, and this causes the substantial increases in OUR and MLVSS once the famine period begins. An analysis of how the OUR is distributed among the several respiration processes shows that the predation of XH is the most significant oxygen utilization rate process in the system under famine conditions of an SBR. Application of the model to simulate the long-term operation of an SBR indicates that predators reach their maximum fraction in the MLVSS (∼4{\%} of MLVSS) at a solids retention time of about 13 days, but they are washed out at a solids retention time less than ∼3 days. Simulation for a continuous system indicates that predators take more time (about 800 h) to reach steady state and reach their maximum fraction (∼5.5{\%}) at an SRT of ∼14 days. Comparison of SBR and continuous systems reveals that the predators have greater impact in the continuous system because the permanent near-famine condition accentuates predation processes.",
author = "Ni, {Bing Jie} and Bruce Rittmann and Yu, {Han Qing}",
year = "2010",
month = "8",
doi = "10.1016/j.watres.2010.05.048",
language = "English (US)",
volume = "44",
pages = "4616--4622",
journal = "Water Research",
issn = "0043-1354",
publisher = "Elsevier Limited",
number = "15",

}

TY - JOUR

T1 - Evaluation on the impacts of predators on biomass components and oxygen uptake in sequencing batch reactor and continuous systems

AU - Ni, Bing Jie

AU - Rittmann, Bruce

AU - Yu, Han Qing

PY - 2010/8

Y1 - 2010/8

N2 - An expanded unified model for the biomass fractions, soluble-organic fractions, and oxygen-uptake rates considering extracellular polymeric substances (EPS), intracellular storage products (XSTO), and predators for activated sludge is used to study the impacts of predators on biomass components and oxygen uptake. The new model is applied to evaluate how predation affects the oxygen-uptake rate (OUR) and the different forms of biomass: active bacteria (XH), XEPS, and XSTO, under dynamic feast-and-famine and continuous conditions. For the dynamic conditions of a sequencing batch reactor (SBR), eliminating predators from the model increases XH and XEPS fractions significantly, and this causes the substantial increases in OUR and MLVSS once the famine period begins. An analysis of how the OUR is distributed among the several respiration processes shows that the predation of XH is the most significant oxygen utilization rate process in the system under famine conditions of an SBR. Application of the model to simulate the long-term operation of an SBR indicates that predators reach their maximum fraction in the MLVSS (∼4% of MLVSS) at a solids retention time of about 13 days, but they are washed out at a solids retention time less than ∼3 days. Simulation for a continuous system indicates that predators take more time (about 800 h) to reach steady state and reach their maximum fraction (∼5.5%) at an SRT of ∼14 days. Comparison of SBR and continuous systems reveals that the predators have greater impact in the continuous system because the permanent near-famine condition accentuates predation processes.

AB - An expanded unified model for the biomass fractions, soluble-organic fractions, and oxygen-uptake rates considering extracellular polymeric substances (EPS), intracellular storage products (XSTO), and predators for activated sludge is used to study the impacts of predators on biomass components and oxygen uptake. The new model is applied to evaluate how predation affects the oxygen-uptake rate (OUR) and the different forms of biomass: active bacteria (XH), XEPS, and XSTO, under dynamic feast-and-famine and continuous conditions. For the dynamic conditions of a sequencing batch reactor (SBR), eliminating predators from the model increases XH and XEPS fractions significantly, and this causes the substantial increases in OUR and MLVSS once the famine period begins. An analysis of how the OUR is distributed among the several respiration processes shows that the predation of XH is the most significant oxygen utilization rate process in the system under famine conditions of an SBR. Application of the model to simulate the long-term operation of an SBR indicates that predators reach their maximum fraction in the MLVSS (∼4% of MLVSS) at a solids retention time of about 13 days, but they are washed out at a solids retention time less than ∼3 days. Simulation for a continuous system indicates that predators take more time (about 800 h) to reach steady state and reach their maximum fraction (∼5.5%) at an SRT of ∼14 days. Comparison of SBR and continuous systems reveals that the predators have greater impact in the continuous system because the permanent near-famine condition accentuates predation processes.

UR - http://www.scopus.com/inward/record.url?scp=77955275184&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77955275184&partnerID=8YFLogxK

U2 - 10.1016/j.watres.2010.05.048

DO - 10.1016/j.watres.2010.05.048

M3 - Article

C2 - 20599242

AN - SCOPUS:77955275184

VL - 44

SP - 4616

EP - 4622

JO - Water Research

JF - Water Research

SN - 0043-1354

IS - 15

ER -