mdh.sePublications
Change search
Link to record
Permanent link

Direct link
BETA
Publications (5 of 5) Show all publications
Krustok, I., Odlare, M., Truu, J. & Nehrenheim, E. (2016). Inhibition of nitrification in municipal wastewater treating photobioreactors: effect on algal growth and nutrient uptake. Bioresource Technology, 202, 238-243
Open this publication in new window or tab >>Inhibition of nitrification in municipal wastewater treating photobioreactors: effect on algal growth and nutrient uptake
2016 (English)In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 202, p. 238-243Article 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.

Keywords
photobioreactors, microalgae, wastewater treatment, nitrification, algal-bacterial interactions
National Category
Water Treatment
Research subject
Energy- and Environmental Engineering
Identifiers
urn:nbn:se:mdh:diva-30043 (URN)10.1016/j.biortech.2015.12.020 (DOI)000367673500032 ()26716890 (PubMedID)2-s2.0-84951304290 (Scopus ID)
Funder
Knowledge Foundation, 2011006VINNOVA, 2012-01243
Available from: 2015-12-21 Created: 2015-12-21 Last updated: 2018-10-16Bibliographically approved
Krustok, I., Odlare, M., M.A., S., Truu, J., Truu, M., Ligi, T. & Nehrenheim, E. (2015). Characterization of algal and microbial community growth in a wastewater treating batch photo-bioreactor inoculated with lake water. Algal Research, 11(Sept), 421-427
Open this publication in new window or tab >>Characterization of algal and microbial community growth in a wastewater treating batch photo-bioreactor inoculated with lake water
Show others...
2015 (English)In: Algal Research, ISSN 2211-9264, Vol. 11, no Sept, p. 421-427Article in journal (Refereed) Published
Abstract [en]

Microalgae grown in photo-bioreactors can be a valuable source of biomass, especially when combined with wastewater treatment. While most published research has studied pure cultures, the consortia of algae and bacteria from wastewater have more complex community dynamics which affect both the biomass production and pollutant removal. In this paper we investigate the dynamics of algal and bacterial growth in wastewater treating batch photo-bioreactors. The photo-bioreactors were inoculated with water from a nearby lake. Lake water was obtained in August, November and December in order to add native algal species and study the effects of the season. The photo-bioreactors inoculated with lake water obtained in August and November produced more biomass and grew faster than those that only contained the algae from wastewater. The results indicated a rapid decline in bacterial abundance before algae began to multiply in reactors supplemented with lake water in November and December. The reactors were also successful in removing nitrogen and phosphorous from wastewater.

Place, publisher, year, edition, pages
Elsevier, 2015
Keywords
Algal cultivation; Biomass production; Community analysis; Photo-bioreactors; Wastewater treatment
National Category
Water Treatment
Research subject
Energy- and Environmental Engineering
Identifiers
urn:nbn:se:mdh:diva-27699 (URN)10.1016/j.algal.2015.02.005 (DOI)000363046900051 ()2-s2.0-84943663075 (Scopus ID)
Funder
Knowledge Foundation, 2011006VINNOVA, 2012-01243
Note

Additional funding from SVU (12-123), Purac and Mälarenergi, and by grant IUT2-16 of the Ministry of Education and Research of the Republic of Estonia (J. Truu, M. Truu, T. Ligi).

Available from: 2015-03-16 Created: 2015-03-16 Last updated: 2017-01-03Bibliographically approved
Krustok, I., Odlare, M., Truu, M., Truu, J., Ligi, T., Tiirik, K. & Nehrenheim, E. (2015). Effect of lake water on algal biomass and microbial community structure in municipal wastewater based lab-scale photobioreactors. Applied Microbiology and Biotechnology, 99(21), 6537-6549
Open this publication in new window or tab >>Effect of lake water on algal biomass and microbial community structure in municipal wastewater based lab-scale photobioreactors
Show others...
2015 (English)In: Applied Microbiology and Biotechnology, ISSN 0175-7598, E-ISSN 1432-0614, Vol. 99, no 21, p. 6537-6549Article in journal (Refereed) Published
Abstract [en]

Photobioreactors are a novel environmental technology that can produce biofuels with the simultaneous removal of nutrients and pollutants from wastewaters. The aim of this study was to evaluate the effect of the lake water addition to the production of algal biomass, and phylogenetic and functional structure of the algal and bacterial communities in the lab-scale bioreactors treating municipal wastewater.

The lake water addition has significant benefit to the overall algal biomass growth and nutrient reduction in the reactors with wastewater and lake water (ratio 70/30 v/v). The metagenome based survey showed that the most abundant algal phylum in these reactors was Chlorophyta with Scenedesmus being the most prominent genus. The most abundant bacterial phyla were Proteobacteria and Bacteroidetes with most dominant families being Sphingobacteriaceae, Cytophagaceae, Flavobacteriaceae, Comamonadaceae, Planctomycetaceae, Nocardiaceae and Nostocaceae. These photobioreactors were also effective in reducing the overall amount of pathogens in wastewater compared to reactors with wastewater/tap water mixture. Functional analysis of the photobioreactor metagenomes revealed an increase in relative abundance genes related to photosynthesis, synthesis of vitamins important for auxotrophic algae, and decrease in virulence and nitrogen metabolism subsystems in lake water reactors.

Keywords
biomass production; metagenome analysis; photobioreactor; wastewater treatment
National Category
Microbiology
Research subject
Biotechnology/Chemical Engineering
Identifiers
urn:nbn:se:mdh:diva-27706 (URN)10.1007/s00253-015-6580-7 (DOI)000357649200031 ()25895091 (PubMedID)2-s2.0-84937630449 (Scopus ID)
Funder
Knowledge Foundation, 2011006VINNOVA, 2012-01243
Note

Additional funding by SVU (12-123), Puracand Mälarenergi, and the Ministry of Education and Research of the Republic of Estonia (grants IUT2-16 and 3.2.0801.11-0026).

Available from: 2015-03-16 Created: 2015-03-16 Last updated: 2018-10-16Bibliographically approved
Krustok, I., Nehrenheim, E., Odlare, M., M.A., S., Truu, J., Ligi, T. & Truu, M. (2014). Characterization of algal and microbial community dynamics in a wastewater photo-bioreactor using indigenous algae from lake mälaren. In: : . Paper presented at 4th International Conference on Algal Biomass Biofuels and Bioproducts.
Open this publication in new window or tab >>Characterization of algal and microbial community dynamics in a wastewater photo-bioreactor using indigenous algae from lake mälaren
Show others...
2014 (English)Conference paper, Oral presentation with published abstract (Other academic)
Abstract [en]

Microalgae grown in photo-bioreactors can be a valuable source for biomass especially when combined with the treatment of wastewater. While most published research has been studying pure cultures, consortia of algae and bacteria from the wastewater have more complex dynamics affecting both the biomass production and pollutant removal. In this paper we investigate dynamics of algal and bacterial communities in mixed culture photo-bioreactors using chlorophyll and real-time PCR analysis. Wastewater photo-bioreactors were inoculated with water from a nearby lake to add native algae species. The results indicated a decline in bacterial 16S rDNA copy numbers before algae started to multiply. The photo-bioreactors inoculated with lake algae produced more biomass and grew faster than the algae originating only from wastewater. The reactors were effective in removing ammonia from the wastewater which seemed work to mostly through nitrification thus causing an increase in nitrate concentration. There was also an increase in Cr, Co and Ni ion concentrations during the experiment suggesting they may have moved from organic complexes to the water phase as free ions.

Keywords
algae cultivation; biomass production; community analysis; photo-bioreactors; wastewater treatment
National Category
Water Treatment
Research subject
Energy- and Environmental Engineering
Identifiers
urn:nbn:se:mdh:diva-26824 (URN)
Conference
4th International Conference on Algal Biomass Biofuels and Bioproducts
Funder
Knowledge FoundationVINNOVA
Available from: 2014-12-03 Created: 2014-12-03 Last updated: 2017-03-09Bibliographically approved
Krustok, I., Oopkaup, K., Truu, J., Odlare, M. & Nehrenheim, E.Comparative analysis of the metagenomes extracted from wastewater treating photobioreactors.
Open this publication in new window or tab >>Comparative analysis of the metagenomes extracted from wastewater treating photobioreactors
Show others...
(English)Manuscript (preprint) (Other academic)
Abstract [en]

The metagenomes of lab-scale municipal wastewater treating batch photobioreactors were studied with a focus on nitrogen metabolism, pathogen abundance and antibiotic resistance genes. Previous studies based on the dataset showed that in general, as algae growth in the reactors increased, nitrogen metabolism and virulence genes decreased. With this study, a more detailed view of these gene groups is presented.

Keywords
photobioreactors, metagenomics, microalgae, wastewater treatment, pathogens, antibiotic resistance, functional analysis
National Category
Water Treatment
Research subject
Biotechnology/Chemical Engineering
Identifiers
urn:nbn:se:mdh:diva-30044 (URN)
Funder
Knowledge Foundation, 2011006VINNOVA, 2012-01243
Available from: 2015-12-21 Created: 2015-12-21 Last updated: 2016-02-25Bibliographically approved
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-1818-6678

Search in DiVA

Show all publications