| |
Records |
Links |
|
Author |
Granskog, M.A.; Virkkunen, K.; Thomas, D.N.; Ehn, J.; Kola, H.; Martma, T. |
|
| |
Title |
Chemical properties of brackish water ice in the Bothnian Bay, the Baltic Sea |
Type |
Journal Article |
| |
Year |
2004 |
Publication |
Journal of Glaciology |
Abbreviated Journal |
J Glaciol |
|
| |
Volume |
50 |
Issue |
169 |
Pages |
292-302 |
|
| |
Keywords |
Dependent Solute Redistribution; Dissolved Organic Matter; Phase Boundary; Sulfate; Binding; Summer; Oxygen; Core; Gulf |
|
| |
Abstract |
The behavior of majors, δ18O, dissolved organic carbon (DOC) and trace elements was studied during the initial freezing of low-saline water (3 practical salinity units) in a freezing experiment. Samples were also collected from first-year sea ice from pack ice in the Bothnian Bay, northern Baltic Sea. During initial ice formation, the major-ion ratios in sea ice indicated variable behavior, with some ions showing relative enrichment (sulfate, calcium and magnesium), conservative behavior (sodium) or relative depletion (potassium) compared to sea water at the same salinity DOC, iron and aluminum showed enrichment in the ice, while zinc was depleted to salinity. Lead was detected in surface snow-ice layers only, implying atmospheric accumulation. First-year sea ice, with a variable growth and thermal history, showed behavior for major ions similar to that observed in new ice. However, for trace elements the picture was much more complicated, most likely due to active secondary processes such as atmospheric supply and biological activity. Ice growth has a potential impact on the chemical budgets and cycling of some elements, especially those which are selectively rejected/retained during sea-ice formation, particularly in the shallow parts of the Bothnian Bay covered with a land-fast ice cover. |
|
| |
Address  |
Granskog: Univ Helsinki, Dept Phys Sci, Div Geophys, FIN-00014 Helsinki, Finland |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
International Glaciological Society |
Place of Publication |
Cambridge |
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0022-1430 |
ISBN |
|
Medium |
|
|
| |
Area |
Baltic Sea; Bothnian Bay |
Expedition |
|
Conference |
|
|
| |
Notes |
ISI:000227720900014 |
Approved |
no |
|
| |
Call Number |
refbase @ admin @ Granskog++2004 |
Serial |
741 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Underwood, G.J.C.; Aslam, S.N.; Michel, C.; Niemi, A.; Norman, L.; Meiners, K.M.; Laybourn-Parry, J.; Paterson, H.; Thomas, D.N. |
|
| |
Title |
Broad-scale predictability of carbohydrates and exopolymers in Antarctic and Arctic sea ice |
Type |
Journal Article |
| |
Year |
2013 |
Publication |
Proceedings of the National Academy of Sciences of the United States of America |
Abbreviated Journal |
Proc Natl Acad Sci U S A |
|
| |
Volume |
110 |
Issue |
39 |
Pages |
15734-15739 |
|
| |
Keywords |
Antarctic Regions; Arctic Regions; Biopolymers/*analysis; Carbohydrates/*analysis; Ice Cover/*chemistry; Models, Chemical; Molecular Weight; Solubility; algae; biogeochemistry; global relationships; microbial |
|
| |
Abstract |
Sea ice can contain high concentrations of dissolved organic carbon (DOC), much of which is carbohydrate-rich extracellular polymeric substances (EPS) produced by microalgae and bacteria inhabiting the ice. Here we report the concentrations of dissolved carbohydrates (dCHO) and dissolved EPS (dEPS) in relation to algal standing stock [estimated by chlorophyll (Chl) a concentrations] in sea ice from six locations in the Southern and Arctic Oceans. Concentrations varied substantially within and between sampling sites, reflecting local ice conditions and biological content. However, combining all data revealed robust statistical relationships between dCHO concentrations and the concentrations of different dEPS fractions, Chl a, and DOC. These relationships were true for whole ice cores, bottom ice (biomass rich) sections, and colder surface ice. The distribution of dEPS was strongly correlated to algal biomass, with the highest concentrations of both dEPS and non-EPS carbohydrates in the bottom horizons of the ice. Complex EPS was more prevalent in colder surface sea ice horizons. Predictive models (validated against independent data) were derived to enable the estimation of dCHO concentrations from data on ice thickness, salinity, and vertical position in core. When Chl a data were included a higher level of prediction was obtained. The consistent patterns reflected in these relationships provide a strong basis for including estimates of regional and seasonal carbohydrate and dEPS carbon budgets in coupled physical-biogeochemical models, across different types of sea ice from both polar regions. |
|
| |
Address |
School of Biological Sciences, University of Essex, Colchester, Essex CO4 3SQ, United Kingdom |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
National Academy of Sciences |
Place of Publication |
Washington, DC |
Editor |
|
|
| |
Language |
English |
Summary Language |
English |
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0027-8424 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:24019487; PMCID:PMC3785782 |
Approved |
no |
|
| |
Call Number |
refbase @ user @ |
Serial |
17491 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Hulatt, C.J.; Thomas, D.N. |
|
| |
Title |
Energy efficiency of an outdoor microalgal photobioreactor sited at mid-temperate latitude |
Type |
Journal Article |
| |
Year |
2011 |
Publication |
Bioresource Technology |
Abbreviated Journal |
Bioresour Technol |
|
| |
Volume |
102 |
Issue |
12 |
Pages |
6687-6695 |
|
| |
Keywords |
Biomass; *Bioreactors; Climate; Geography; Microalgae/growth & development/*metabolism; Oxygen/metabolism; Scenedesmus/growth & development/*metabolism; Seasons; Solar Energy |
|
| |
Abstract |
This work examined the energetic performance of a 6-month semi-continuous cultivation of Scenedesmus obliquus in an outdoor photobioreactor at mid-temperate latitude, without temperature control. By measuring the seasonal biomass production (mean 11.31, range 1.39-23.67 g m(-2)d(-1)), higher heating value (22.94 kJ g(-1)) and solar irradiance, the mean seasonally-averaged photosynthetic efficiency (2.18%) and gross energy productivity (0.27 MJ m(-2) d(-1)) was calculated. When comparing the solar energy conversion efficiency to the energy investment for culture circulation, significant improvements in reactor energy input must be made to make the system viable. Using the data collected to model the energetic performance of a substitute photobioreactor design, we conclude that sustainable photobioreactor cultivation of microalgae in similar temperate climates requires a short light path and low power input, only reasonably obtained by flat-panel systems. However, temperature control was not necessary for effective long-term cultivation. |
|
| |
Address |
School of Ocean Sciences, College of Natural Sciences, Bangor University, Askew Street, Menai Bridge, Anglesey LL59 5AB, UK. osp418@bangor.ac.uk |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0960-8524 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:21511466 |
Approved |
no |
|
| |
Call Number |
refbase @ user @ |
Serial |
12984 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Hulatt, C.J.; Thomas, D.N. |
|
| |
Title |
Productivity, carbon dioxide uptake and net energy return of microalgal bubble column photobioreactors |
Type |
Journal Article |
| |
Year |
2011 |
Publication |
Bioresource Technology |
Abbreviated Journal |
Bioresour Technol |
|
| |
Volume |
102 |
Issue |
10 |
Pages |
5775-5787 |
|
| |
Keywords |
*Bioreactors; Carbon Dioxide/*metabolism; Energy Metabolism; Equipment Design; Microalgae/growth & development/*metabolism; Photochemistry |
|
| |
Abstract |
This work examined the energy return of Chlorella vulgaris and Dunaliella tertiolecta cultivated in a gas-sparged photobioreactor design where the power input for sparging was manipulated (10, 20, and 50 Wm(-3)). Dry weight, organic carbon and heating values of the biomass were measured, plus a suite of variables including Fv/Fm and dissolved oxygen. A model for predicting the higher heating value of microalgal biomass was developed and used to measure the energetic performance of batch cultivations. High power inputs enhanced maximum biomass yields, but did not improve the energy return. Cultivation in 10 Wm(-3) showed up to a 39% higher cumulative net energy return than 50 Wm(-3), and increased the cumulative net energy ratio up to fourfold. The highest net energy ratio for power input was 19.3 (D. tertiolecta, 12% CO(2), 10 Wm(-3)). These systems may be a sustainable method of biomass production, but their effectiveness is sensitive to operational parameters. |
|
| |
Address |
School of Ocean Sciences, College of Natural Sciences, Bangor University, Askew Street, Menai Bridge, Isle of Anglesey LL59 5AB, UK. osp418@bangor.ac.uk |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0960-8524 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:21376576 |
Approved |
no |
|
| |
Call Number |
refbase @ user @ |
Serial |
12983 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Hulatt, C.J.; Thomas, D.N. |
|
| |
Title |
Dissolved organic matter (DOM) in microalgal photobioreactors: a potential loss in solar energy conversion? |
Type |
Journal Article |
| |
Year |
2010 |
Publication |
Bioresource Technology |
Abbreviated Journal |
Bioresour Technol |
|
| |
Volume |
101 |
Issue |
22 |
Pages |
8690-8697 |
|
| |
Keywords |
Bioreactors/*microbiology; Chlorella vulgaris/*physiology; Culture Media/chemistry; *Electric Power Supplies; Energy Transfer; Organic Chemicals/*chemistry/*metabolism; Photochemistry/*instrumentation; Solubility |
|
| |
Abstract |
Microalgae are considered to be a potential alternative to terrestrial crops for bio-energy production due to their relatively high productivity per unit area of land. In this work we examined the amount of dissolved organic matter exuded by algal cells cultured in photobioreactors, to examine whether a significant fraction of the photoassimilated biomass could potentially be lost from the harvestable biomass. We found that the mean maximum amount of dissolved organic carbon (DOC) released measured 6.4% and 17.3% of the total organic carbon in cultures of Chlorellavulgaris and Dunaliella tertiolecta, respectively. This DOM in turn supported a significant growth of bacterial biomass, representing a further loss of the algal assimilated carbon. The release of these levels of DOC indicates that a significant fraction of the photosynthetically fixed organic matter could be lost into the surrounding water, suggesting that the actual biomass yield per hectare for industrial purposes could be somewhat less than expected. A simple and inexpensive optical technique, based on chromophoric dissolved organic matter (CDOM) measurements, to monitor such losses in commercial PBRs is discussed. |
|
| |
Address |
School of Ocean Sciences, College of Natural Sciences, Bangor University, Menai Bridge, Anglesey, UK. osp418@bangor.ac.uk |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0960-8524 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:20634058 |
Approved |
no |
|
| |
Call Number |
refbase @ user @ |
Serial |
12981 |
|
| Permanent link to this record |
