5 resultados para fauna and flora
em AMS Tesi di Laurea - Alm@DL - Università di Bologna
Resumo:
The EBPR (Enhanced Biological Phosphorus Removal) is a type of secondary treatment in WWTPs (WasteWater Treatment Plants), quite largely used in full-scale plants worldwide. The phosphorus occurring in aquatic systems in high amounts can cause eutrophication and consequently the death of fauna and flora. A specific biomass is used in order to remove the phosphorus, the so-called PAOs (Polyphosphate Accumulating Organisms) that accumulate the phosphorus in form of polyphosphate in their cells. Some of these organisms, the so-called DPAO (Denitrifying Polyphosphate Accumulating Organisms) use as electron acceptor the nitrate or nitrite, contributing in this way also to the removal of these compounds from the wastewater, but there could be side reactions leading to the formation of nitrous oxides. The aim of this project was to simulate in laboratory scale a EBPR, acclimatizing and enriching the specialized biomass. Two bioreactors were operated as Sequencing Batch Reactors, one enriched in Accumulibacter, the other in Tetrasphaera (both PAOs): Tetrasphaera microorganisms are able to uptake aminoacids as carbon source, Accumulibacter uptake organic carbon (volatile fatty acids, VFA). In order to measure the removal of COD, phosphorus and nitrogen-derivate compounds, different analysis were performed: spectrophotometric measure of phosphorus, nitrate, nitrite and ammonia concentrations, TOC (Total Organic Carbon, measuring the carbon consumption), VFA via HPLC (High Performance Liquid Chromatography), total and volatile suspended solids following standard methods APHA, qualitative microorganism population via FISH (Fluorescence In Situ Hybridization). Batch test were also performed to monitor the NOx production. Both specialized populations accumulated as a result of SBR operations; however, Accumulibacter were found to uptake phosphates at higher extents. Both populations were able to remove efficiently nitrates and organic compounds occurring in the feeding. The experimental work was carried out at FCT of Universidade Nova de Lisboa (FCT-UNL) from February to July 2014.
Resumo:
An analysis and a subsequent solution is here presented. This document is about a groin design able to contrast the erosion actions given by waves in Lido di Dante. Advantages will be visible also for Fiumi Uniti's inlet, in the north side of the shoreline. Beach future progression and growth will be subjected to monitoring actions in the years after groin construction. The resulting effects of the design will have a positive impact not only on the local fauna and environment, but also, a naturalistic appeal will increase making new type of tourists coming not only for recreational purposes. The design phase is focused on possible design alternatives and their features. Particular interest is given to scouring phenomena all around the groin after its construction. Groin effects will impact not only on its south side, instead they will cause an intense erosion process on the downdrift front. Here, many fishing hut would be in danger, thus a beach revetment structure is needed to avoid any future criticality. In addiction, a numerical model based on a generalized shoreline change numerical model, also known as GENESIS, has been applied to the study area in order to perform a simplistic analysis of the shoreline and its future morphology. Critical zones are visible in proximity of the Fiumi Uniti's river inlet, where currents from the sea and the river itself start the erosion process that is affecting Lido di Dante since mid '80s, or even before. The model is affected by several assumptions that make results not to be interpreted as a real future trend of the shore. Instead the model allows the user to have a more clear view about critical processes induced by monochromatic inputed waves. In conclusion, the thesis introduce a wide analysis on a complex erosion process that is affecting many shoreline nowadays. A groin design is seen as a hard solution it is considered to be the only means able to decrease the rate of erosion.
Resumo:
In order to increase fertility of agricultural soils, in the framework of circular economy, the use of soil amendments such as biochar, compost, and mixtures of the two, has been implemented in recent years. Although it has been demonstrated that their use can improve the physico-chemical characteristics of soil and plant yield, few studies investigated the effect of these amendments on the soil fauna, and consequently the biological quality of soils. This study aimed to provide information on soil fauna, in particular microarthropods , in plots of an experimental vineyard treated with different soil amendments (biochar, compost, and CB mix, i.e. a mixture of biochar and compost) compared to untreated plots. What emerged from this study is that taxa abundances are significantly increased in compost-treated soil samples compared to untreated and CB mix ones. The value of the QBS-ar index obtained in soil samples treated with CB mix is lower than in samples treated with compost, biochar, and untreated, although the difference was not statistically significant. The physico-chemical soil characteristics are, in general, significantly more favorable in samples treated with CB mix than in the control, although the soil fauna seems to be partially negatively influenced by the treatment with CB mix. In fact, the number of taxa, in particular the number of taxa most adapted to edaphic life, are significantly negatively affected by the application of the CB mix. Concluding, improved physico-chemical characteristics induced by soil amendments do not always correspond to a positive response of the soil fauna, at least with respect to the QBS-ar approach.
Resumo:
Food items and nematode parasites were identified from the stomachs of 42 individuals of Phocoena phocoena, 6 of Lagenorhynchus acutus and 8 of L. albirostris stranded off the coastal waters of Northern Scotland between 2004 and 2014. Post-mortem examinations have revealed heavy parasitic worm burdens. Four nematode species complex as Anisakis spp., Contracaeucum spp., Pseudoterronova spp., and Hysterothylacium spp. were recorded. Data on presence of the anisakid species in cetaceans, reported a significative relationship between the presence of Hysterothylacium and the month of host stranding; suggesting a decrease of larval H. aduncum abundance in the period between April and August due to a seasonal effect related to prey availability. Similarly, the parasite burden of the all anisakid genera was related to the year fraction of stranding, and a relationship statistically significant was found just for L. albirostris with an increase between April and October. This finding is explained by a seasonality in occurrence of white-beaked dolphins, with a peak during August, that might be related to movements of shared prey species and competition with other species (Tursiops truncatus). Geographical differences were observed in parasites number of all anisakid species, which was the highest in cetaceans from the East area and lowest in the North coast. The parasites number also increased significantly with the length of the animal and during the year, but with a significant seasonal pattern only for P. phocoena. Regarding diet composition, through a data set consisting of 34 harbour porpoises and 1 Atlantic white-sided dolphins, we found a positive association between parasite number and the cephalopods genus Alloteuthis. This higher level of parasite infection in squid from this area, is probably due to a quantitative distribution of infective forms in squid prey, an abundance of the final host and age or size maturity of squid.
Resumo:
Polychaetes are one of the larger groups of macroinvertebrates with more than 9000 species recognised, distributed worldwide. Thanks to the broad ecological adaptability and high abundaces, this taxon plays a leading role and is considered an important component of all benthic assemblages. Our knowledge about the West Iberian Coast polychaete fauna are scarce, and the only studies are recent. In this sense, the aim of this work was to investigate the composition and the spatial distribution of the polychaete fauna along the NW Portuguese Coastal Shelf, focusing on their relationship to environmental factors (depth, grain size, longitude and latitude) and to add new data to the existing biological dataset. A total of 39 sites were analysed, collected in an area of about 5665 km², between 20 and 150 m depth, distributed in a way to cover the overall grain size gradient. A total of 9352 specimens belonging to 41 families were found, and the analysis based on the abundance of polychaete species revealed five affinity groups: (a) nearshore medium sand characterised by Pisione parapari and Hesionura elongata; (b) very coarse sand that showed the highest abundance of Syllidae and was characterised by Protodorvillea kefersteini and Syllis garciai; (c) fine sand dominated by Spiophanes bombyx and Glycera tridactyla; (d) very fine sand with Nepthys assimilis and Amage sp. and the highest abundance of Paraonidae; (d) mud characterised by Labioleanira yhleni and Ampharete finmarchica. The combination of the environmental variables and the biological data, done with BIOENV routine, demonstrated that depth, grain size and fine contents were the best related with the biological data (rho=0.598). In general, the results agree with the composition and the spatial distribution of the polychaete fauna in other parts of the world; further polychaete assemblages related to mud sediments were firstly recorded in the Northwestern Portuguese Coastal Shelf.