mdh.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Inhibition of nitrification in municipal wastewater treating photobioreactors: effect on algal growth and nutrient uptake
Mälardalen University, School of Business, Society and Engineering, Future Energy Center. (ACWA)ORCID iD: 0000-0002-4435-4367
Mälardalen University, School of Business, Society and Engineering, Future Energy Center.ORCID iD: 0000-0001-5480-0167
University of Tartu, Estonia.ORCID iD: 0000-0003-1818-6678
Mälardalen University, School of Business, Society and Engineering, Future Energy Center. (ACWA)ORCID iD: 0000-0003-3311-9465
2016 (English)In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 202, 238-243 p.Article in journal (Refereed) Published
Abstract [en]

The effect of inhibiting nitrification on algal growth and nutrient uptake was studied in photobioreactors treating municipal wastewater. As previous studies have indicated that algae prefer certain nitrogen species to others, and because nitrifying bacteria are inhibited by microalgae, it is important to shed more light on these interactions. In this study allylthiourea (ATU) was used to inhibit nitrification in wastewater-treating photobioreactors. The nitrification-inhibited reactors were compared to control reactors with no ATU added.

Microalgae had higher growth in the inhibited reactors, resulting in a higher chlorophyll a concentration. The species mix also differed, with Chlorella and Scenedesmus being the dominant genera in the control reactors and Cryptomonas and Chlorella dominating in the inhibited reactors. The nitrogen speciation in the reactors after 8 days incubation was also different in the two setups, with N existing mostly as NH4-N in the inhibited reactors and as NO3-N in the control reactors.

Place, publisher, year, edition, pages
2016. Vol. 202, 238-243 p.
Keyword [en]
photobioreactors, microalgae, wastewater treatment, nitrification, algal-bacterial interactions
National Category
Water Treatment
Research subject
Energy- and Environmental Engineering
Identifiers
URN: urn:nbn:se:mdh:diva-30043DOI: 10.1016/j.biortech.2015.12.020ISI: 000367673500032Scopus ID: 2-s2.0-84951304290OAI: oai:DiVA.org:mdh-30043DiVA: diva2:885739
Funder
Knowledge Foundation, 2011006VINNOVA, 2012-01243
Available from: 2015-12-21 Created: 2015-12-21 Last updated: 2016-02-25Bibliographically approved
In thesis
1. Microbiological analysis of municipal wastewater treating photobioreactors
Open this publication in new window or tab >>Microbiological analysis of municipal wastewater treating photobioreactors
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Microalgae reactors, commonly known as photobioreactors, have become increasingly popular as an alternative for wastewater treatment. These systems reduce pollutants and remove nutrients such as nitrogen and phosphorous compounds from wastewater utilizing microalgae and bacteria. The biomass produced in the reactors can potentially be used to produce biofuels and decrease some of the energy demands of the process.

Wastewater treating photobioreactors are a relatively new technology and many aspects of their microbiology need further study. This thesis presents a broad overview of the algal and bacterial communities present in these systems by looking at the most important species, metabolic pathways and growth dynamics of both algae and bacteria.

The experiments presented in this thesis were conducted using municipal wastewater from the Västerås wastewater treatment plant. The wastewater was inoculated with algae from Lake Mälaren and compared to non-inoculated reactors. Overall, the inoculated reactors demonstrated better algal growth than those that were not inoculated. The tested systems also removed much of the ammonium and phosphorous present in the wastewater.

The dominant algae in the tested systems belonged to the genera Scenedesmus, Desmodesmus and Chlorella. In addition to algae, the systems contained a large number of bacteria, mostly from the phyla Proteobacteria and Bacteroidetes.

The algal photobioreactors contained a lower abundance of genes related to nitrogen metabolism, virulence and antibiotic resistance compared to the initial wastewater, showing that a shift in the bacterial community had occurred. The bacteria found in the systems were shown to be involved in synthesis of vitamins essential for algae growth such as vitamin B12, suggesting cooperation between the bacteria and algae.

Abstract [sv]

I takt med att världens befolkning ökar, så produceras dagligen allt mer avfall. Detta kan orsaka stora problem för miljön. När det byggs nya system för vattenrening behöver vi även ta hänsyn till kravet att minska energiåtgången. Dagens vattenreningssystem har vissa tillkortakommanden när det gäller reningsnivåer och energianvändning. Ett alternativ till dagens system, kan vara fotobioreaktorer, dvs. vattenrening med hjälp av mikroalger. Dessa system använder mikroalger och bakterier för att rena vattnet från föroreningar, kväve och fosfor.

Vattenrening med fotobioreaktorer är en relativt ny teknik. Flera aspekter gällande biologin i dessa system har ännu inte studerats i detalj. Den här avhandlingen presenterar en översikt av de alger och bakterier som är aktiva i fotobioreaktorer. Andra viktiga aspekter som tillväxt, arter samt vattenreningsförmåga har också studerats.

Ett antal försök genomfördes där alger från Mälaren tillsattes i vatten från Västerås kommunala vattenreningsanläggning. Storleken på försöken varierade mellan 250 ml och 20 liter. Det visade sig att algerna hade en bra tillväxt samt att mängden ammonium och fosfor minskade i vattnet under försöksperioden.

De alger som tillväxte mest i studien tillhörde Scenedesmus, Desmodesmus och Chlorella. Förutom alger tillväxte även ett stort antal bakterier från grupperna Proteobacteria and Bacteroidetes. Dessa bakterier visade sig syntetisera viktiga vitaminer, t.ex. vitamin B12, som algerna normalt inte kan syntetisera själva.

Sammanfattningsvis, så presenterar denna avhandling viktig information gällande alger och bakterier i en fotobioreaktor. Informationen kan vara ett viktigt bidrag till framtida utveckling av storskaliga fotobioreaktorer för vattenrening.

Place, publisher, year, edition, pages
Västerås: Mälardalen University, 2016
Series
Mälardalen University Press Dissertations, ISSN 1651-4238 ; 196
Keyword
photobioreactors, wastewater treatment, microalgae, microbiology
National Category
Water Treatment
Research subject
Energy- and Environmental Engineering
Identifiers
urn:nbn:se:mdh:diva-30045 (URN)978-91-7485-251-6 (ISBN)
Public defence
2016-01-29, Paros, Mälardalens högskola, Västerås, 09:15 (English)
Opponent
Supervisors
Funder
Knowledge Foundation, 2011006VINNOVA, 2012-01243
Available from: 2015-12-21 Created: 2015-12-21 Last updated: 2016-01-13Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Krustok, IvoOdlare, MonicaTruu, JaakNehrenheim, Emma
By organisation
Future Energy Center
In the same journal
Bioresource Technology
Water Treatment

Search outside of DiVA

GoogleGoogle Scholar

Altmetric score

Total: 166 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf