ELECTROPHORESIS AND BIOPHYSICAL CHARACTERIZATION OF SARCOSINE OXIDASE - MODIFICATION OF MAGNETIC NANOPARTICLES

This paper presents a novel procedure for the treatment of contaminated water with high concentrations of nitrates, which are considered as one of the main causes of the eutrophication phenomena. For this purpose, magnetic nanoparticles functionalized with silver (Fe3O4@AgNPs) were synthesized and used as an adsorbent of nitrates. Experimental conditions, including the pH, adsorbent and adsorbate dose, temperature and contact time, were analyzed to obtain the highest adsorption efficiency for different concentration of nitrates in water. A maximum removal efficiency of 100% was reached for 2, 5, 10 and 50 mg/L of nitrate at pH = 5, room temperature, and 50, 100, 250 and 500 µL of Fe3O4@AgNPs, respectively. The characterization of the adsorbent, before and after adsorption, was performed by energy dispersive X-ray spectroscopy, scanning electron microscopy, Brunauer-Emmett-Teller analysis and Fourier-transform infrared spectroscopy. Nitrates can be desorbed, and the adsorbent can be reused using 500 µL of NaOH solution 0.01 M, remaining unchanged for the first three cycles, and exhibiting 90% adsorption efficiency after three regenerations. A deep study on equilibrium isotherms reveals a pH-dependent behavior, characterized by Langmuir and Freundlich models at pH = 5 and pH = 1, respectively. Thermodynamic studies were consistent with physicochemical adsorption for all experiments but showed a change from endothermic to exothermic behavior as the temperature increases. Interference studies of other ions commonly present in water were carried out, enabling this procedure as very selective for nitrate ions. In addition, the method was applied to real samples of seawater, showing its ability to eliminate the total nitrate content in eutrophized waters.

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Production and characterization of chitooligosaccharides by the fungal chitinase Chit42 immobilized on magnetic nanoparticles and chitosan beads: selectivity, specificity and improved operational utility

RSC Advances ◽

10.1039/d0ra10409d ◽

2021 ◽

Vol 11 (10) ◽

pp. 5529-5536

Author(s):

Peter E. Kidibule ◽

Jessica Costa ◽

Andrea Atrei ◽

Francisco J. Plou ◽

Maria Fernandez-Lobato ◽

...

Keyword(s):

Magnetic Nanoparticles ◽

Industrial Application ◽

Chitosan Beads

Chitin-active enzymes are of great biotechnological interest due to the wide industrial application of chitinolytic materials.

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Remote Sensing Methods for the Biophysical Characterization of Protected Areas Globally: Challenges and Opportunities

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi10060384 ◽

2021 ◽

Vol 10 (6) ◽

pp. 384

Author(s):

Javier Martínez-López ◽

Bastian Bertzky ◽

Simon Willcock ◽

Marine Robuchon ◽

María Almagro ◽

...

Keyword(s):

Remote Sensing ◽

Protected Areas ◽

Large Scale ◽

Anthropogenic Activities ◽

Global Scale ◽

Area Network ◽

Biophysical Characterization ◽

Challenges And Opportunities ◽

Scale Characterization

Protected areas (PAs) are a key strategy to reverse global biodiversity declines, but they are under increasing pressure from anthropogenic activities and concomitant effects. Thus, the heterogeneous landscapes within PAs, containing a number of different habitats and ecosystem types, are in various degrees of disturbance. Characterizing habitats and ecosystems within the global protected area network requires large-scale monitoring over long time scales. This study reviews methods for the biophysical characterization of terrestrial PAs at a global scale by means of remote sensing (RS) and provides further recommendations. To this end, we first discuss the importance of taking into account the structural and functional attributes, as well as integrating a broad spectrum of variables, to account for the different ecosystem and habitat types within PAs, considering examples at local and regional scales. We then discuss potential variables, challenges and limitations of existing global environmental stratifications, as well as the biophysical characterization of PAs, and finally offer some recommendations. Computational and interoperability issues are also discussed, as well as the potential of cloud-based platforms linked to earth observations to support large-scale characterization of PAs. Using RS to characterize PAs globally is a crucial approach to help ensure sustainable development, but it requires further work before such studies are able to inform large-scale conservation actions. This study proposes 14 recommendations in order to improve existing initiatives to biophysically characterize PAs at a global scale.

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