2023, Articolo in rivista, ENG
Kamburska Lyudmila, Zaupa Silvia, Boggero Angela
For the first time, the size spectra of 28 chironomid genera/species are reported for the most common chironomid taxa in the deep subalpine Lake Maggiore (northwestern Italy). Species-specific length-mass regression models were developed to predict the dry masses of the larval stages of Cladotanytarsus sp., Cryptochironomus sp., Polypedilum bicrenatum, P. nubeculosum, and Stictochironomus pictulus. The predicted dry-mass values differed by less than 20% from the measured values, suggesting that these original equations will be important in chironomid production studies. Regressions at the subfamily level were also developed for case identification at the genus or species level, which is difficult to obtain. The chironomid weights were determined directly and a dry/wet-weight-conversion ratio was estimated. The results were consistent with previously reported results. The relationships between the dry masses and the body lengths were compared with published data for different types of lake all over the world. We found that regression models for other freshwater environments somehow differed from those in Lake Maggiore, albeit slightly. The combination of diversity-based and trait-based approaches improves our knowledge about chironomids and our understanding of the effects of global environmental changes on freshwater biota. This first collection of trait data on summer-autumn chironomid assemblages in a temperate subalpine lake is a valuable contribution to the European trait database. The taxonomic diversity and abundance of chironomids were uploaded for open access on the GBIF platform.
DOI: 10.3390/w15152730
2020, Articolo in rivista, ENG
Bartoli M., Rosi L., Giovannelli A., Frediani P., Frediani M.
Olive pruning residue is largely formed during cultivation, and is usually disposed through open-air combustion directly in the field, but this habit is a possible source of pollution. The pyrolytic conversion of olive pruning residue has been run in a new and very appealing way using microwave as a heating source and different microwave absorbers in a multimode batch reactor. In this way, olive residue is converted into interesting bio-chemical products with a short pyrolysis time, ranging from 15 to 36 min, and with a peak temperature ranging from 450 K to 705 K according to the different microwave absorber. Thus, a very efficient and selective system was realized, which was able to address the process towards the formation of a large amount of bio-char (up to 61.2%) or a high formation of bio-oil (56.2%) and gas (41.7%) with a very low formation of bio-char (2.1%). However, when carbon and iron were used as microwave absorbers, it was possible to obtain an intermediate amount of bio-char (26-30%) and bio-oil (40 wt%). Bio-oils were collected as dark-brown liquids with low viscosity and density. A bio-oil with a low water concentration was obtained using carbon or iron as the microwave absorber. The bio-oils formed in all experiments contained a very large amount of acetic acid, even when NaOH was the microwave absorber. Furthermore, a large amount of aromatics were present in the bio-oil obtained using carbon as the microwave absorber.
2019, Articolo in rivista, ENG
Califano, Valeria; Costantini, Aniello; Silvestri, Brigida; Venezia, Virginia; Cimino, Stefano; Sannino, Filomena
?-Glucosidase (BG) was immobilized by adsorption on wrinkled silica nanoparticles (WSNs) and on tannic acid-templated mesoporous silica nanoparticles (TA-MSNPs). The effect induced by a different morphology of the pores of the sorbent on the catalytic performance of ?-glucosidase was investigated. A complete textural and morphological characterization of the two samples was performed by Brunauer-Emmett-Teller (BET) method, Fourier Transform Infrared (FT-IR) and transmission electron microscopy (TEM). The results demonstrated that the catalytic performance of the immobilized enzyme depends on the pores size of sorbent but a key factor is the pores morphology. In fact, the BG immobilized on WSNs and TA-MSNPs (BG/WSNs and BG/TA-MSNPs) shows in both cases good catalytic performances in cellobiose hydrolysis, but the catalyst with the best performance is BG/WSNs, in which the support exhibits a central-radial pore structure and a hierarchical trimodal micro-mesoporous pore size. This peculiar morphology allows the enzyme to settle in a place where the interactions with the walls are maximized, increasing its conformational rigidity. Furthermore, the enzyme is prevalently collocated in the interior of pore so that the pores are not completely capped.