Denitrification on internal carbon sources in RAS is limited by fibers in fecal waste of rainbow trout

A. Meriac, E.H. Eding, A. Kamstra, J.P. Busscher, J.W. Schrama, J.A.J. Verreth

Research output: Contribution to journalArticleAcademicpeer-review

9 Citations (Scopus)

Abstract

Denitrification on internal carbon sources offers the advantage to control nitrate levels in recirculating aquaculture systems (RAS) by using the fecal carbon produced within the husbandry system. However, it is not clear to which extent fecal carbon can be utilized by the microbial community within a denitrification reactor. Especially fibers can hamper the bioavailability of carbon in fecal waste. Therefore, this study investigated the nitrogen removal capacity of a denitrification reactor using fecal waste with a high fiber content as the only carbon source in RAS. Furthermore, we investigated to which extent fibers were utilized as a carbon source within the reactor. Four identical small-scale RAS (V = 460 L) were stocked with 25 rainbow trout of ~ 110 g, and operated at a water exchange rate of ~ 200 L/kg of feed DM. Two RAS served as controls without denitrification and two RAS were upgraded with an upflow sludge blanket denitrification reactor (V = 10.5 L). During the six weeks of experiment, we determined COD (chemical oxygen demand, measure for organic carbon) and N balances for all systems and analyzed the composition of the collected solids. The denitrification reactors were able to remove 19 g N/kg of feed DM, or 48% of the metabolic nitrogen waste produced by the fish. Based on the COD balances, 44% of the supplied fecal COD was degraded in the reactor. Hemicellulose and cellulose degradability was ~ 50%, accounting for 45% to the total degraded COD. Under steady state conditions, 4.4 g of biodegradable COD needed to be oxidized to reduce 1 g of nitrogen, indicating respiratory COD losses of approximately 50%. This experiment successfully demonstrated that denitrification on internal carbon sources using a high fiber diet could remove half of the nitrogen waste produced by the fish. Although fibers limited carbon bioavailability, half of the cellulose and hemicellulose present in the fecal waste was utilized in the denitrification reactor.
Original languageEnglish
Pages (from-to)264-271
JournalAquaculture
Volume434
DOIs
Publication statusPublished - 2014

Fingerprint

aquaculture system
recirculating aquaculture systems
denitrification
rainbow
Oncorhynchus mykiss
carbon
nitrogen
dietary fiber
bioavailability
hemicellulose
cellulose
fibre
high fiber diet
biodegradability
water exchange
fish
reactor
exchange rate
chemical oxygen demand
fiber content

Keywords

  • recirculating aquaculture systems
  • single-sludge denitrification
  • acid-insoluble ash
  • nitrate removal
  • digestibility
  • feed
  • fish
  • effluents
  • digestion
  • culture

Cite this

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title = "Denitrification on internal carbon sources in RAS is limited by fibers in fecal waste of rainbow trout",
abstract = "Denitrification on internal carbon sources offers the advantage to control nitrate levels in recirculating aquaculture systems (RAS) by using the fecal carbon produced within the husbandry system. However, it is not clear to which extent fecal carbon can be utilized by the microbial community within a denitrification reactor. Especially fibers can hamper the bioavailability of carbon in fecal waste. Therefore, this study investigated the nitrogen removal capacity of a denitrification reactor using fecal waste with a high fiber content as the only carbon source in RAS. Furthermore, we investigated to which extent fibers were utilized as a carbon source within the reactor. Four identical small-scale RAS (V = 460 L) were stocked with 25 rainbow trout of ~ 110 g, and operated at a water exchange rate of ~ 200 L/kg of feed DM. Two RAS served as controls without denitrification and two RAS were upgraded with an upflow sludge blanket denitrification reactor (V = 10.5 L). During the six weeks of experiment, we determined COD (chemical oxygen demand, measure for organic carbon) and N balances for all systems and analyzed the composition of the collected solids. The denitrification reactors were able to remove 19 g N/kg of feed DM, or 48{\%} of the metabolic nitrogen waste produced by the fish. Based on the COD balances, 44{\%} of the supplied fecal COD was degraded in the reactor. Hemicellulose and cellulose degradability was ~ 50{\%}, accounting for 45{\%} to the total degraded COD. Under steady state conditions, 4.4 g of biodegradable COD needed to be oxidized to reduce 1 g of nitrogen, indicating respiratory COD losses of approximately 50{\%}. This experiment successfully demonstrated that denitrification on internal carbon sources using a high fiber diet could remove half of the nitrogen waste produced by the fish. Although fibers limited carbon bioavailability, half of the cellulose and hemicellulose present in the fecal waste was utilized in the denitrification reactor.",
keywords = "recirculating aquaculture systems, single-sludge denitrification, acid-insoluble ash, nitrate removal, digestibility, feed, fish, effluents, digestion, culture",
author = "A. Meriac and E.H. Eding and A. Kamstra and J.P. Busscher and J.W. Schrama and J.A.J. Verreth",
year = "2014",
doi = "10.1016/j.aquaculture.2014.08.004",
language = "English",
volume = "434",
pages = "264--271",
journal = "Aquaculture",
issn = "0044-8486",
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Denitrification on internal carbon sources in RAS is limited by fibers in fecal waste of rainbow trout. / Meriac, A.; Eding, E.H.; Kamstra, A.; Busscher, J.P.; Schrama, J.W.; Verreth, J.A.J.

In: Aquaculture, Vol. 434, 2014, p. 264-271.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Denitrification on internal carbon sources in RAS is limited by fibers in fecal waste of rainbow trout

AU - Meriac, A.

AU - Eding, E.H.

AU - Kamstra, A.

AU - Busscher, J.P.

AU - Schrama, J.W.

AU - Verreth, J.A.J.

PY - 2014

Y1 - 2014

N2 - Denitrification on internal carbon sources offers the advantage to control nitrate levels in recirculating aquaculture systems (RAS) by using the fecal carbon produced within the husbandry system. However, it is not clear to which extent fecal carbon can be utilized by the microbial community within a denitrification reactor. Especially fibers can hamper the bioavailability of carbon in fecal waste. Therefore, this study investigated the nitrogen removal capacity of a denitrification reactor using fecal waste with a high fiber content as the only carbon source in RAS. Furthermore, we investigated to which extent fibers were utilized as a carbon source within the reactor. Four identical small-scale RAS (V = 460 L) were stocked with 25 rainbow trout of ~ 110 g, and operated at a water exchange rate of ~ 200 L/kg of feed DM. Two RAS served as controls without denitrification and two RAS were upgraded with an upflow sludge blanket denitrification reactor (V = 10.5 L). During the six weeks of experiment, we determined COD (chemical oxygen demand, measure for organic carbon) and N balances for all systems and analyzed the composition of the collected solids. The denitrification reactors were able to remove 19 g N/kg of feed DM, or 48% of the metabolic nitrogen waste produced by the fish. Based on the COD balances, 44% of the supplied fecal COD was degraded in the reactor. Hemicellulose and cellulose degradability was ~ 50%, accounting for 45% to the total degraded COD. Under steady state conditions, 4.4 g of biodegradable COD needed to be oxidized to reduce 1 g of nitrogen, indicating respiratory COD losses of approximately 50%. This experiment successfully demonstrated that denitrification on internal carbon sources using a high fiber diet could remove half of the nitrogen waste produced by the fish. Although fibers limited carbon bioavailability, half of the cellulose and hemicellulose present in the fecal waste was utilized in the denitrification reactor.

AB - Denitrification on internal carbon sources offers the advantage to control nitrate levels in recirculating aquaculture systems (RAS) by using the fecal carbon produced within the husbandry system. However, it is not clear to which extent fecal carbon can be utilized by the microbial community within a denitrification reactor. Especially fibers can hamper the bioavailability of carbon in fecal waste. Therefore, this study investigated the nitrogen removal capacity of a denitrification reactor using fecal waste with a high fiber content as the only carbon source in RAS. Furthermore, we investigated to which extent fibers were utilized as a carbon source within the reactor. Four identical small-scale RAS (V = 460 L) were stocked with 25 rainbow trout of ~ 110 g, and operated at a water exchange rate of ~ 200 L/kg of feed DM. Two RAS served as controls without denitrification and two RAS were upgraded with an upflow sludge blanket denitrification reactor (V = 10.5 L). During the six weeks of experiment, we determined COD (chemical oxygen demand, measure for organic carbon) and N balances for all systems and analyzed the composition of the collected solids. The denitrification reactors were able to remove 19 g N/kg of feed DM, or 48% of the metabolic nitrogen waste produced by the fish. Based on the COD balances, 44% of the supplied fecal COD was degraded in the reactor. Hemicellulose and cellulose degradability was ~ 50%, accounting for 45% to the total degraded COD. Under steady state conditions, 4.4 g of biodegradable COD needed to be oxidized to reduce 1 g of nitrogen, indicating respiratory COD losses of approximately 50%. This experiment successfully demonstrated that denitrification on internal carbon sources using a high fiber diet could remove half of the nitrogen waste produced by the fish. Although fibers limited carbon bioavailability, half of the cellulose and hemicellulose present in the fecal waste was utilized in the denitrification reactor.

KW - recirculating aquaculture systems

KW - single-sludge denitrification

KW - acid-insoluble ash

KW - nitrate removal

KW - digestibility

KW - feed

KW - fish

KW - effluents

KW - digestion

KW - culture

U2 - 10.1016/j.aquaculture.2014.08.004

DO - 10.1016/j.aquaculture.2014.08.004

M3 - Article

VL - 434

SP - 264

EP - 271

JO - Aquaculture

JF - Aquaculture

SN - 0044-8486

ER -