Publications by authors named "Hans Chr Bruun Hansen"

Phosphorus (P) losses from tile-drained agricultural fields may degrade surface water quality by accelerating eutrophication. Among the different edge-of-field technologies, compact filter systems using different filter materials have been identified as potentially effective solutions for removing P from drainage water before discharge downstream. This study investigated the long-term (>696 days) P removal efficiency of 5 different filter materials in a column setup, using artificial drainage water (pH 6).

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Trace element polluted soils pose risks to human and environmental health. Biochar can decrease trace element bioavailability in soils, but their resulting ability to reduce soil toxicity may vary significantly depending on feedstocks used, pyrolysis conditions, and the target pollutants. Chromated copper arsenate (CCA) polluted sites are common, but only very few types of biochar have been tested for these sites.

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The potential toxicity and ecological risks of rare-earth nanoparticles in the environment have become a concern due to their widespread application and inevitable releases. The integration of hydroponics experiments, partial least squares structural equation modeling (PLS-SEM), and Transmission Electron Microscopy (TEM) were utilized to investigate the physiological toxicity, uptake and translocation of yttrium oxide nanoparticles (YO NPs) under different hydroponic treatments (1, 5, 10, 20, 50 and 100 mg·L of YO NPs, 19.2 mg·L Y(NO) and control) in tomato (Lycopersicon esculentum) seedlings.

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Article Synopsis
  • Phytotoxins, specifically toxic alkaloids, are produced by lupins and other Fabaceae family plants, but their environmental effects remain largely unexplored.
  • A field experiment measured the presence of these alkaloids in various samples including lupin tissues and drainage water, with lupanine being the most prevalent compound detected.
  • The cumulative amount of alkaloids found in drainage water was minimal compared to the total in lupin biomass, but significant amounts were transported during heavy rainfall, highlighting potential contamination risks for surface water in agricultural regions.
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The impact of land use type on the content of potentially toxic elements (PTEs) in the soils of the Qinghai-Tibet Plateau (QTP) and the associated ecological and human health risks has drawn great attention. Consequently, in this study, top- and subsurface soil samples were collected from areas with four different land uses (i.e.

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We investigated how sulfur (S) application prior to wheat cultivation under wheat-rice rotation influences the uptake of cadmium (Cd) in rice grown in low- and high-Cd soils. A pot experiment was conducted with four S levels (0, 30, 60, 120 mg S kg) and two Cd rates (low and high, 0.35 and 10.

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Layered double hydroxides (LDH) and their magnetic composites have been intensively investigated as recyclable high-capacity phosphate sorbents but with little attention to their stability as function of pH and phosphate concentration. The stability of a FeO@SiO-MgFe LDH P sorbent as function of pH (5-11) and orthophosphate (P) concentration (1-300 mg P/L) was investigated. The composite has high adsorption capacity (approx.

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Adsorption onto two-dimensional nanosheet materials offers new possibilities for fast and efficient removal of contaminants from waters. Here, the adsorption of As(V) to a new type of iron oxides - single sheet iron oxide (SSI) - has been studied as a function of time, loading and pH. Adsorption of As(V) onto SSI was very fast compared to other iron oxides, with 80% of total As(V) adsorbed within 10 min.

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Saponins form a group of plant-produced glycosides with potential as biopesticide ingredients. The environmental fate of saponins has never been fully investigated. In the present study, we use QS-18, a specific saponin from Quillaja saponaria as an example, to quantify hydrolysis under different conditions of pH, temperature and water chemical composition.

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Saponin-rich plant extracts contain bioactive natural compounds and have many applications, e.g. as biopesticides and biosurfactants.

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Saponin-rich extracts from Quillaja saponaria and Chenopodium quinoa have been registered by US EPA as active ingredients in biopesticides, and extract from tea seed powder, Camellia oleifera has been proposed for biocidal use. If saponin-rich biopesticides are efficient against pests, they are most likely also bioactive in the aquatic environment against non-target organisms. The aim of this study was to conduct an effect assessment of saponin-rich plant extracts by using species sensitivity distributions based on acute toxicity tests.

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A novel zinc (Zn) fertilizer concept based on Zn-doped layered double hydroxides (Zn-doped Mg-Fe-LDHs) has been investigated. Zn-doped Mg-Fe-LDHs were synthesized, their chemical composition was analyzed, and their nutrient release was studied in buffered solutions with different pH values. Uptake of Zn by barley (Hordeum vulgare cv.

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Heavy metal contaminated surface water is one of the oldest pollution problems, which is critical to ecosystems and human health. We devised disulfide linked polymer networks and employed as a sorbent for removing heavy metal ions from contaminated water. Although the polymer network material has a moderate surface area, it demonstrated cadmium removal efficiency equivalent to highly porous activated carbon while it showed 16 times faster sorption kinetics compared to activated carbon, owing to the high affinity of cadmium towards disulfide and thiol functionality in the polymer network.

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Sintering and steel production as the main emission sources of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) may affect environment and human health. The concentrations, profiles, and distributions of PCDD/Fs in soil samples from around four typical sintering and steel production plants in Hebei Province, China, were determined. Forty-six soil samples were collected at distances from 500 to 9000 m from industrial plant chimneys.

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Long-range atmospheric transportation (LRAT) of persistent organic pollutants followed by their deposition in cold, arid regions is of wide concern. This problem occurs at Qinghai Lake in the northeastern Tibetan Plateau, a sparsely populated area with extreme weather conditions and little current or historical anthropogenic pollution. The concentrations and distribution patterns of the mono-to octa-chlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) congeners in surface soil samples collected from around Qinghai Lake were quantified.

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