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Unusual photodegradation reactions of Asteraceae and Poaceae grass pollen enzymatic extracts on P25 photocatalyst
2021
Sapiña, Maria | Jimenez-Relinque, Eva | Roman, Elisa | Nevshupa, Roman | Castellote, Marta
In previous studies, it was demonstrated that photocatalysis by TiO₂ nanoparticles can be effective for decomposition of pollen grains and pollen allergen extracts (PAEs) for Cupressus arizonica and Platanus hybrida species. In this work, the chemical and photochemical processes of five types of PAEs belonging to family Asteraceae, tribe Astereae, and family Poaceae, tribes Poeae and Triticea, were studied. It was confirmed that the PAEs suffered almost complete decomposition, which likely led to gaseous final products. For the species of Poeae tribe, i.e., Poa pratensis, Festuca pratensis, and Avena sativa, an unusual surface chemical modification of the photocatalyst consisting in the appearance of new bands on fine core level spectra of Ti 2p, C 1s, and O 1s was observed. These changes were associated with possible doping of TiO₂ with C and N by pollen extracts. This was accompanied by a red shift of absorption spectra. The results suggest that some components of Poeae pollen can be grafted on TiO₂ surface and they can activate the photocatalyst in the visible range. These findings can open a new pathway to eco-friendly chemical engineering of photocatalysts using organic biological compounds.
Show more [+] Less [-]Long-term persistence of seeded grass species: an unwanted side effect of ecological restoration
2016
Rydgren, Knut | Auestad, Inger | Hamre, Liv Norunn | Hagen, Dagmar | Rosef, Line | Skjerdal, Gudrun
Spoil heaps are the visible footprint of hydropower production, particularly in vulnerable alpine environments. Speeding up vegetation development by seeding commercial grass species has been a common restoration practice for the last 50 years, but we lack information on whether seeded species decline and allow native plant cover to develop. We visually estimated cover of native vascular plants and five seeded grass species (Agrostis capillaris, Festuca ovina, Festuca rubra, Schedonorus pratensis and Phleum pratense) on eight spoil heaps at different elevations (boreal–alpine zone) in western Norway. Spoil heap vegetation was censused twice (9–20 and 24–36 years after spoil heap construction); the undisturbed surrounding vegetation was also censused on the second occasion. Total cover on the spoil heaps showed some increase, but remained far below that in surrounding areas. Cover of seeded grass species in the surroundings was low (but not negligible), indicating suboptimal establishment ability. Seeded species usually covered less than 20 % of the spoil heaps, and only F. rubra, F. ovina and A. capillaris contributed substantially. Proportional cover indicated better initial establishment by seeded species, but their cover decreased between the censuses on all but the highest located spoil heap. The persistence of seeded grass species is problematic, and despite the decrease in proportional cover, they are likely to persist for decades on spoil heaps, posing a risk of invasion of surrounding areas. We therefore recommend replacing the practice of seeding with more appropriate restoration measures.
Show more [+] Less [-]Uptake and translocation of organophosphates and other emerging contaminants in food and forage crops
2013
Eggen, Trine | Heimstad, Eldbjørg S. | Stuanes, A. O. (Arne O.) | Norli, Hans Ragnar
Emerging contaminants in wastewater and sewage sludge spread on agricultural soil can be transferred to the human food web directly by uptake into food crops or indirectly following uptake into forage crops. This study determined uptake and translocation of the organophosphates tris(1-chloro-2-propyl) phosphate (TCPP) (log Kₒw2.59), triethyl-chloro-phosphate (TCEP) (log Kₒw1.44), tributyl phosphate (TBP) (log Kₒw4.0), the insect repellent N,N-diethyl toluamide (DEET) (log Kₒw2.18) and the plasticiser N-butyl benzenesulfonamide (NBBS) (log Kₒw2.31) in barley, wheat, oilseed rape, meadow fescue and four cultivars of carrot. All species were grown in pots of agricultural soil, freshly amended contaminants in the range of 0.6–1.0 mg/kg dry weight, in the greenhouse. The bioconcentration factors for root (RCF), leaf (LCF) and seed (SCF) were calculated as plant concentration in root, leaf or seed over measured initial soil concentration, both in dry weight. The chlorinated flame retardants (TCEP and TCPP) displayed the highest bioconcentration factors for leaf and seed but did not show the same pattern for all crop species tested. For TCEP, which has been phased out due to toxicity but is still found in sewage sludge and wastewater, LCF was 3.9 in meadow fescue and 42.3 in carrot. For TCPP, which has replaced TCEP in many products and also occurs in higher residual levels in sewage sludge and wastewater, LCF was high for meadow fescue and carrot (25.9 and 17.5, respectively). For the four cultivars of carrot tested, the RCF range for TCPP and TCEP was 10–20 and 1.7–4.6, respectively. TCPP was detected in all three types of seeds tested (SCF, 0.015–0.110). Despite that DEET and NBBS have log Kₒwin same range as TCPP and TCEP, generally lower bioconcentration factors were measured. Based on the high translocation of TCPP and TCEP to leaves, especially TCPP, into meadow fescue (a forage crop for livestock animals), ongoing risk assessments should be conducted to investigate the potential effects of these compounds in the food web.
Show more [+] Less [-]The appreciation of mineral element accumulation level in some herbaceous plants species by ICP-AES method
2010
Elekes, Carmen Cristina | Dumitriu, Irina | Busuioc, Gabriela | Iliescu, Nicoleta S
Introduction From the metallurgic industry zone of Dambovita County, we harvested and analyzed seven herbaceous plants species (Lolium perenne, Festuca pratensis, Stipa capillata, Agrostis alba, Cynodon dactylon, Luzula campestris, and Agrostis tenuis) to establish the heavy metal accumulation levels in these species. Materials and method The heavy metal contents (for Cr, Mn, Zn, Sr, Cu, Ba, and Sn) were determined by analyzing the dry matter with an inductively coupled plasma-atomic emission spectrometer. This method has detection limits of 0.4-0.6 mg/kg for the analyzed metals. The heavy metal concentrations in plants harvested from the industrial area are in milligram per kilogram of dry matter and ranged from 10.03 to 191.98 mg/kg of dry matter for Cr, 165.89 to 1,103.92 mg/kg of dry matter for Mn, 62.09 to 921.67 mg/kg of dry matter for Zn, 29.21 to 50.12 mg/kg of dry matter for Sr, 0.99 to 113.83 mg/kg of dry matter for Cu, 58.66 to 133.51 mg/kg of dry matter for Ba, and 8.38 to 276.44 mg/kg of dry matter for Sn. The heavy metal accumulation levels in the studied species of plants were calculated by the rapport between the concentration level of the metal in plant samples and the level of the same metal in the soil, near the radicular system for each species of plants. Results The highest accumulation levels were found in A. alba for Cr (267.69%); in L. perenne for Mn (51.45%), Sr (114.35%), and Ba (60.81%); and in C. dactylon for Zn (136.62%), Cu (97.65%), and F. pratensis for Sn (704.00%).
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