ABSTRACT
European Commission has approached the challenge of End-Of-Life (EOL) fishing gear and Abandoned, Lost, or otherwise Discarded Fishing Gear (ALDFG) by focusing on circular economy. Current directives highlight the need to provide a proper management to EOL fishing gears, fostering their separate collection, transport, and treatment from a circular perspective. They also request Member States to set collection and treatment targets. However, this is far from being widely implemented in a coordinated manner. In the quest to explore the Spanish case, this contribution aims at providing insights on the amount and type of EOL fishing gear and management practices carried out in different Spanish ports, as well as recycling options for such gears. Data was collected through an online survey, interviews to stakeholders, and visits to ports. Composition, degradation and mechanical recyclability of EOL samples were assessed. Yearly, 1643 tonnes of EOL fishing gear (mainly nets) are discarded in Spanish ports from trawling (97.5%), gillnet/trammel nets (2.3%) and purse seine (0.2%) fisheries. High-density polyethylene (from trawling nets) is the most common discarded polymer, followed by polyamide 6 (from gillnets/trammel net and purse seine nets). EOL fishing gear management is diverse in Spain as it depends on the nature of the port (who governs it, either regional or national govern), special agreements between local fishers' guilds and waste managing companies, the waste managers in port, etc. Polyamide nets are degraded but in good condition to be recycled mechanically; for trawl nets chemical recycling is more suited due to their degraded state. Currently, few recycling companies exists in Spain that are engaged on mechanical recycling of EOL fishing gears, none in chemical recycling. Therefore, a more comprehensive analysis, coordination, and smart logistics are needed to make the collection and recycling of EOL fishing gear possible.
Subject(s)
Fisheries , Hunting , SpainABSTRACT
Almond (Prunus amygdalus) is one of the most common tree nuts on a worldwide basis. This nut is highly regarded in the food and cosmetic industries. However, for all these applications, almonds are used without their shell protection, which is industrially removed contributing approximately 35-75% of the total fruit weight. This residue is normally incinerated or dumped, causing several environmental problems. In this study, a novel cellulose nanocrystal (CNCs) extraction procedure from almond shell (AS) waste by using microwave-assisted extraction was developed and compared with the conventional approach. A three-factor, three-level Box-Behnken design with five central points was used to evaluate the influence of extraction temperature, irradiation time, and NaOH concentration during the alkalization stage in crystallinity index (CI) values. A similar CI value (55.9 ± 0.7%) was obtained for the MAE process, comprising only three stages, compared with the conventional optimized procedure (55.5 ± 1.0%) with five stages. As a result, a greener and more environmentally friendly CNC extraction protocol was developed with a reduction in time, solvent, and energy consumption. Fourier transform infrared (FTIR) spectra, X-ray diffractogram (XRD), atomic force microscopy (AFM), and scanning electron microscopy (SEM) images, and thermal stability studies of samples confirmed the removal of non-cellulosic components after the chemical treatments. TEM images revealed a spherical shape of CNCs with an average size of 21 ± 6 nm, showing great potential to be used in food packaging, biological, medical, and photoelectric materials. This study successfully applied MAE for the extraction of spherical-shaped CNCs from AS with several advantages compared with the conventional procedure, reducing costs for industry.
ABSTRACT
The depolymerization process of PET by glycolysis into BHET monomer is optimized in terms of reaction temperature and time, by carrying out the process under pressure to be faster for reducing the energy required. Almost pure BHET has been obtained by working in a pressure reactor at 3 bar both at 220 and 180 °C after short reaction times, while for longer ones a mixture of oligomers and dimers is obtained. Depending on the potential application required, the obtention of different reaction products is controlled by adjusting reaction temperature and time. The use of a pressure reactor allows work at lower temperatures and shorter reaction times, obtaining almost pure BHET. To the best of our knowledge, except for microwave-assisted procedures, it is the first time in which pure BHET is obtained after such short reaction times, at lower temperatures than those usually employed.
