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| 2. |
- Schück, Maria, 1986-
(författare)
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Heavy metal removal by floating treatment wetlands: Plant selection
- 2019
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Elevated levels of heavy metals and chloride are commonly found in stormwater, as a consequence of pollution from traffic, building material and industries, and the use of salt for deicing in wintertime. Floating treatment wetlands (FTWs), consisting of vegetated rafts that can be placed in stormwater ponds, may be able to reduce heavy metal and chloride concentrations, but until this date have mainly been used for nutrient removal in warm climates. Plants are essential in FTWs as pollutants are taken up into plant tissues, adsorbed to exposed plant surfaces, precipitated due to chemical interactions with root exudates or bound to plant litter.The aim of the study was to examine: A) which plant species that should be used on FTWs in a cool climate for efficient heavy metal and chloride removal, and B) to identify plant traits that are connected to high pollutant removal capacity as a help for identification of additional suitable species.Thirty-four wetland plant species, all growing in wild in Sweden, were used in the study. These were all grown hydroponically for 5 days in a solution containing 1.2 µg Cd L–1, 68.5 µg Cu L–1 ¸ 78.4 µg Pb L–1, 559 µg Zn L–1 and 55.4 mg Cl L-1. Carex pseudocyperus and Carex riparia were found to quickly reduce the concentration of all added heavy metals, and keep the concentration low for the remainder of the exposure period. In addition, nine species were able to remove all metals except cadmium quickly. High removal capacity of metals was found to be connected to biomass traits, mainly large fine root and leaf biomass, and to transpiration, which is correlated with to leaf biomass. Twenty-three of the tested species have also been evaluated for their chloride uptake, and Phalaris arundinacea and Glyceria maxima were identified as the species with highest chloride removal capacity. Preliminary analysis show that the correlation between biomass and chloride removal capacity is weaker than for heavy metals.In conclusion, the removal capacity of heavy metals and chloride differs between plant species, which can be explained by differences in the traits of the plants. The findings indicate that removal of both heavy metals and chloride can be achieved by FTWs in cold climates using a combination of native plants.
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| 3. |
- Schück, Maria, 1986-, et al.
(författare)
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Plant traits related to the heavy metal removal capacities of wetland plants
- 2019
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Ingår i: International journal of phytoremediation. - : Informa UK Limited. - 1522-6514 .- 1549-7879. ; 22:4, s. 427-435
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Tidskriftsartikel (refereegranskat)abstract
- Plants are the crucial component of floating treatment wetlands (FTWs). However, heavy metal removal capacity varies between plant species, and the relationships between plant traits and differences in removal capacity remain unclear. This study sought to determine: (1) the relationships between plant traits and removal of Cd, Cu, Pb, and Zn from water, and (2) the relationships between the removal patterns of these metals. Plants of 34 wetland plant species were exposed to heavy metal concentrations common in stormwater for five days, and 20 traits were measured on each plant. Results indicate that the most important plant traits for heavy metal removal from water are transpiration and high total biomass, especially large amounts of fine roots and leaves. The same traits were generally related to removal both initially and after longer exposure, with stronger correlations found after longer exposure. Plant removal of one metal was likely correlated with removal of the other metals, and the plant removal capacity after 30 min of exposure was correlated with the removal capacity five days later. The present results can be used in selecting plants for enhanced heavy metal removal by FTWs and in identifying additional useful plant species, allowing adaptation to local conditions.
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| 4. |
- Alhousari, Fadi, et al.
(författare)
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Silicon and Mechanisms of Plant Resistance to Insect Pests
- 2018
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Ingår i: PLANTS. - : MDPI AG. - 2223-7747. ; 7:2
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Forskningsöversikt (refereegranskat)abstract
- This paper reviews the most recent progress in exploring silicon-mediated resistance to herbivorous insects and the mechanisms involved. The aim is to determine whether any mechanism seems more common than the others as well as whether the mechanisms are more pronounced in silicon-accumulating than non-silicon-accumulating species or in monocots than eudicots. Two types of mechanisms counter insect pest attacks: physical or mechanical barriers and biochemical/molecular mechanisms (in which Si can upregulate and prime plant defence pathways against insects). Although most studies have examined high Si accumulators, both accumulators and non-accumulators of silicon as well as monocots and eudicots display similar Si defence mechanisms against insects.
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| 5. |
- Bergqvist, Claes, et al.
(författare)
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Phytostabilization of arsenic
- 2015
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Ingår i: In-Situ Remediation of Arsenic-Contaminated Sites. - Boca Raton : CRC Press. - 9780203120170 - 9780415620857 ; , s. 53-67
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Bokkapitel (refereegranskat)
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| 6. |
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| 7. |
- Finnveden, Göran, et al.
(författare)
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Policy Instruments towards a sustainable waste management
- 2016
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Ingår i: Solid waste management: Policy and planning for a sustainable society. - : Apple Academic Press. - 9781771883740 - 9780429091650 ; , s. 185-246, s. 185-246
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 8. |
- Fischer, Benjamin M. C., et al.
(författare)
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Mojito, Anyone? An Exploration of Low-Tech Plant Water Extraction Methods for Isotopic Analysis Using Locally-Sourced Materials
- 2019
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Ingår i: Frontiers in Earth Science. - : Frontiers Media SA. - 2296-6463. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- The stable isotope composition of water (delta O-18 and delta H-2) is an increasingly utilized tool to distinguish between different pools of water along the soil-plant-atmosphere continuum (SPAC) and thus provides information on how plants use water. Clear bottlenecks for the ubiquitous application of isotopic analysis across the SPAC are the relatively high-energy and specialized materials required to extract water from plant materials. Could simple and cost-effective do-it-yourself MacGyver methods be sufficient for extracting plant water for isotopic analysis? This study develops a suite of novel techniques for plant water extraction and compares them to a standard research-grade water extraction method. Our results show that low-tech methods using locally-sourced materials can indeed extract plant water consistently and comparably to what is done with other state-of-the-art methods. Further, our findings show that other factors play a larger role than water extraction methods in achieving the desired accuracy and precision of stable isotope composition: (1) appropriate transport, (2) fast sample processing and (3) efficient workflows. These results are methodologically promising for the rapid expansion of isotopic investigations, especially for citizen science and/or school projects or in remote areas, where improved SPAC understanding could help manage water resources to fulfill agricultural and other competing water needs.
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| 9. |
- Gorbach, Tetiana, et al.
(författare)
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Longitudinal association between hippocampus atrophy and episodic-memory decline
- 2017
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Ingår i: Neurobiology of Aging. - : Elsevier BV. - 0197-4580 .- 1558-1497. ; 51, s. 167-176
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Tidskriftsartikel (refereegranskat)abstract
- There is marked variability in both onset and rate of episodic-memory decline in aging. Structural magnetic resonance imaging studies have revealed that the extent of age-related brain changes varies markedly across individuals. Past studies of whether regional atrophy accounts for episodic-memory decline in aging have yielded inconclusive findings. Here we related 15-year changes in episodic memory to 4-year changes in cortical and subcortical gray matter volume and in white-matter connectivity and lesions. In addition, changes in word fluency, fluid IQ (Block Design), and processing speed were estimated and related to structural brain changes. Significant negative change over time was observed for all cognitive and brain measures. A robust brain-cognition change-change association was observed for episodic-memory decline and atrophy in the hippocampus. This association was significant for older (65-80 years) but not middle-aged (55-60 years) participants and not sensitive to the assumption of ignorable attrition. Thus, these longitudinal findings highlight medial-temporal lobe system integrity as particularly crucial for maintaining episodic-memory functioning in older age.
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| 10. |
- Greger, Maria, et al.
(författare)
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Influence of silicon on arsenic uptake and toxicity in lettuce
- 2015
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Ingår i: Journal of Applied Botany and Food Quality / Angewandte Botanik. - : Druckerei und Verlag Liddy Halm. - 1613-9216 .- 1439-040X. ; 88, s. 234-240
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Tidskriftsartikel (refereegranskat)abstract
- Lettuce grown in soil is found to contain high concentrations of arsenic (As). This paper investigates the uptake and speciation of As in lettuce as well as the influence of silicon (Si) on As uptake, since Si may decrease it. Lettuce plants were cultivated in nutrient solution containing arsenite or arsenate with or without silicate. The uptake and distribution of As between roots and shoots, As accu-mulation in cell walls, As speciation, and toxic effects on growth were analysed. Results indicate that arsenite was more toxic to lettuce than was arsenate. Silicate decreased arsenate toxicity but had little effect on arsenite toxicity. In contrast, Si decreased arsenite uptake more than arsenate uptake. The concentration of arsenate was higher than that of arsenite in the plants independent of the As species added. When arsenate was added, the As concentration in shoots was half of that in the roots and this distribution did not change with Si addition. When arsenite was added, approximately 10% of As was found in the shoots and 90% in the roots; this pattern changed in the presence of Si, and As became evenly distributed in the plant. In both roots and shoots, approximately 40% of the As was found in the cell wall fraction; when arsenite was added, the presence of Si increased this fraction to 47%, but only in the shoots. The extraction efficiency when analysing the As species was lower in shoots than in roots, especially in the presence of arsenite and Si. The opposite was found for As concentration in pellets after extraction. This indicated variation in the binding strength of arsenite and arsenate between roots and shoots and between Si-and non-Si-treated plants.
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