Effect of slow biodegradable substrate addition on biofilm structure and reactor performance in two MBBRs filled with different support media

Elham Ashrafi*, Edris Allahyari, Elena Torresi, Henrik Rasmus Andersen

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

In this study, two moving-bed biofilm reactors (MBBR 1 and MBBR 2) filled with different size of carrier media (Kaldnes K 1 and Kaldnes K 1 micro, respectively) were subjected to soluble (sugar and sodium acetate (Ac)) substrate and mixture of soluble and particulate (particulate potato starch (PS)) substrate in a very high organic loading rate (12 kgCOD/m 3·d) at different temperatures (26 and 15°C, in MBBR 1 and MBBR 2, respectively). The effects of carrier type and substrate on biofilm structure and reactor performance have been studied. Starch was removed by adsorption at the biofilm surface and hydrolyzed which caused substrate gradient in MBBR 1, however, hydrolyzed uniformly within biofilm in MBBR 2. The biofilm of MBBR 1 was irregular due to filamentous structure growth due to the substrate gradient, while, it was regular in MBBR 2 due to uniform distribution of substrate. The performance of both MBBRs in ammonium, COD and TN removal decreased significantly when the amount of small particles in the reactor increased owing to feeding by starch, which led to biomass density decline. The type of media affected the quantity and distribution of attached biomass, which in turn influenced the activity of specific microbial functional groups in the biofilm. The biofilm in MBBR 2 was thicker and consequently nitrogen removal by denitrification was much higher. The lower temperature did not affect negatively the reactor performance in MBBR 2.

Original languageEnglish
JournalEnvironmental Technology
ISSN0959-3330
DOIs
Publication statusAccepted/In press - 2019

Keywords

  • MBBR
  • Particle size distribution
  • Potato starch
  • Simultaneous nitrification de-nitrification (SND)
  • Slowly biodegradable substrate

Cite this

@article{4448f0a37ca043af80833b480204e58d,
title = "Effect of slow biodegradable substrate addition on biofilm structure and reactor performance in two MBBRs filled with different support media",
abstract = "In this study, two moving-bed biofilm reactors (MBBR 1 and MBBR 2) filled with different size of carrier media (Kaldnes K 1 and Kaldnes K 1 micro, respectively) were subjected to soluble (sugar and sodium acetate (Ac)) substrate and mixture of soluble and particulate (particulate potato starch (PS)) substrate in a very high organic loading rate (12 kgCOD/m 3·d) at different temperatures (26 and 15°C, in MBBR 1 and MBBR 2, respectively). The effects of carrier type and substrate on biofilm structure and reactor performance have been studied. Starch was removed by adsorption at the biofilm surface and hydrolyzed which caused substrate gradient in MBBR 1, however, hydrolyzed uniformly within biofilm in MBBR 2. The biofilm of MBBR 1 was irregular due to filamentous structure growth due to the substrate gradient, while, it was regular in MBBR 2 due to uniform distribution of substrate. The performance of both MBBRs in ammonium, COD and TN removal decreased significantly when the amount of small particles in the reactor increased owing to feeding by starch, which led to biomass density decline. The type of media affected the quantity and distribution of attached biomass, which in turn influenced the activity of specific microbial functional groups in the biofilm. The biofilm in MBBR 2 was thicker and consequently nitrogen removal by denitrification was much higher. The lower temperature did not affect negatively the reactor performance in MBBR 2.",
keywords = "MBBR, Particle size distribution, Potato starch, Simultaneous nitrification de-nitrification (SND), Slowly biodegradable substrate",
author = "Elham Ashrafi and Edris Allahyari and Elena Torresi and Andersen, {Henrik Rasmus}",
year = "2019",
doi = "10.1080/09593330.2019.1581261",
language = "English",
journal = "Environmental Technology",
issn = "0959-3330",
publisher = "CRC Press/Balkema",

}

Effect of slow biodegradable substrate addition on biofilm structure and reactor performance in two MBBRs filled with different support media. / Ashrafi, Elham; Allahyari, Edris; Torresi, Elena; Andersen, Henrik Rasmus.

In: Environmental Technology, 2019.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Effect of slow biodegradable substrate addition on biofilm structure and reactor performance in two MBBRs filled with different support media

AU - Ashrafi, Elham

AU - Allahyari, Edris

AU - Torresi, Elena

AU - Andersen, Henrik Rasmus

PY - 2019

Y1 - 2019

N2 - In this study, two moving-bed biofilm reactors (MBBR 1 and MBBR 2) filled with different size of carrier media (Kaldnes K 1 and Kaldnes K 1 micro, respectively) were subjected to soluble (sugar and sodium acetate (Ac)) substrate and mixture of soluble and particulate (particulate potato starch (PS)) substrate in a very high organic loading rate (12 kgCOD/m 3·d) at different temperatures (26 and 15°C, in MBBR 1 and MBBR 2, respectively). The effects of carrier type and substrate on biofilm structure and reactor performance have been studied. Starch was removed by adsorption at the biofilm surface and hydrolyzed which caused substrate gradient in MBBR 1, however, hydrolyzed uniformly within biofilm in MBBR 2. The biofilm of MBBR 1 was irregular due to filamentous structure growth due to the substrate gradient, while, it was regular in MBBR 2 due to uniform distribution of substrate. The performance of both MBBRs in ammonium, COD and TN removal decreased significantly when the amount of small particles in the reactor increased owing to feeding by starch, which led to biomass density decline. The type of media affected the quantity and distribution of attached biomass, which in turn influenced the activity of specific microbial functional groups in the biofilm. The biofilm in MBBR 2 was thicker and consequently nitrogen removal by denitrification was much higher. The lower temperature did not affect negatively the reactor performance in MBBR 2.

AB - In this study, two moving-bed biofilm reactors (MBBR 1 and MBBR 2) filled with different size of carrier media (Kaldnes K 1 and Kaldnes K 1 micro, respectively) were subjected to soluble (sugar and sodium acetate (Ac)) substrate and mixture of soluble and particulate (particulate potato starch (PS)) substrate in a very high organic loading rate (12 kgCOD/m 3·d) at different temperatures (26 and 15°C, in MBBR 1 and MBBR 2, respectively). The effects of carrier type and substrate on biofilm structure and reactor performance have been studied. Starch was removed by adsorption at the biofilm surface and hydrolyzed which caused substrate gradient in MBBR 1, however, hydrolyzed uniformly within biofilm in MBBR 2. The biofilm of MBBR 1 was irregular due to filamentous structure growth due to the substrate gradient, while, it was regular in MBBR 2 due to uniform distribution of substrate. The performance of both MBBRs in ammonium, COD and TN removal decreased significantly when the amount of small particles in the reactor increased owing to feeding by starch, which led to biomass density decline. The type of media affected the quantity and distribution of attached biomass, which in turn influenced the activity of specific microbial functional groups in the biofilm. The biofilm in MBBR 2 was thicker and consequently nitrogen removal by denitrification was much higher. The lower temperature did not affect negatively the reactor performance in MBBR 2.

KW - MBBR

KW - Particle size distribution

KW - Potato starch

KW - Simultaneous nitrification de-nitrification (SND)

KW - Slowly biodegradable substrate

U2 - 10.1080/09593330.2019.1581261

DO - 10.1080/09593330.2019.1581261

M3 - Journal article

JO - Environmental Technology

JF - Environmental Technology

SN - 0959-3330

ER -