Bioavailability of mercury in contaminated soils assessed by the diffusive gradient in thin film technique in relation to uptake by Miscanthus  ×  giganteus

2019 ◽  
Vol 38 (2) ◽  
pp. 321-328 ◽  
Author(s):  
Andrea Ridošková ◽  
Aurélie Pelfrêne ◽  
Francis Douay ◽  
Pavlína Pelcová ◽  
Vendula Smolíková ◽  
...  
Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1464
Author(s):  
Leon Katona ◽  
Yvonne Vadeboncoeur ◽  
Christopher T. Nietch ◽  
Katie Hossler

Recent studies suggest that photophysiological parameters for intact substrates with depth (e.g., periphytic biofilms, microphytobenthos) are overestimated by pulse-amplitude modulated (PAM) fluorometry. This overestimation results from depth-integration effects, following the activation of deeper photosynthesizing layers by an attenuated light signal. To mitigate this error, we propose a novel slide-based thin-film technique in which fluorescence is measured on a vertically representative subsample of the biofilm, spread evenly on a microscope slide. We compared bias and precision for photosynthetic parameters estimated through conventional PAM fluorometry on intact biofilms and through our novel slide-based technique, both theoretically and empirically. Numerical simulations confirmed the consistent overestimation of key parameters for intact biofilms, with relative errors up to 145%, compared to, at most, 52% on thin films. Paired empirical observations likewise demonstrated that estimates based on intact biofilms were consistently higher (up to 248%, p<0.001) than estimates from thin films. Numerical simulation suggested greater precision with the slide-based technique for homogeneous biofilms, but potentially less precision for heterogeneous biofilms with improper subsampling. Our empirical comparison, however, demonstrated some improvement in precision with the slide-based technique (e.g., the coefficient of variation for the maximum electron transport rate was reduced 30%, p=0.009). We recommend the use of the slide-based technique, particularly for biofilms that are thick or have small light attenuation coefficients. Care should be taken, however, to obtain vertically representative subsamples of the biofilm for measurement.


Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 798
Author(s):  
Valentina Pidlisnyuk ◽  
Andriy Herts ◽  
Volodymyr Khomenchuk ◽  
Aigerim Mamirova ◽  
Oleksandr Kononchuk ◽  
...  

Miscanthus × giganteus (M. × giganteus) is a perspective plant produced on marginal and contaminated lands with biomass used for energy or bioproducts. In the current study, M. × giganteus development was tested in the diesel-contaminated soils (ranged from 250 mg kg−1 to 5000 mg kg−1) and the growth dynamic, leaves quantity, plants total area, number of harvested stems and leaves, SPAD and NPQt parameters were evaluated. Results showed a remarkable M. × giganteus growth in a selected interval of diesel-contaminated soil with sufficient harvested biomass. The amendment of soil by biochar 1 (produced from wastewater sludge) and biochar 2 (produced from a mixture of wood waste and biohumus) improved the crop’s morphological and physiological parameters. Biochar 1 stimulated the increase of the stems’ biomass, while biochar 2 increased the leaves biomass. The plants growing in the uncontaminated soil decreased the content of NO3, pH (KCl), P2O5 and increased the content of NH4. Photosynthesis parameters showed that incorporating biochar 1 and biochar 2 to the diesel-contaminated soil prolonged the plants’ vegetation, which was more potent for biochar 1. M. × giganteus utilization united with biochar amendment can be recommended to remediate diesel-contaminated land in concentration range 250–5000 mg kg−1.


2019 ◽  
Vol 2 ◽  
pp. 100023 ◽  
Author(s):  
Edouard Metzger ◽  
Anthony Barbe ◽  
Florian Cesbron ◽  
Aubin Thibault de Chanvalon ◽  
Thierry Jauffrais ◽  
...  

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