Suchergebnisse

Abstract In the last decades several companies worldwide pain significant interest on microalgae production biotechnology as these microorganisms are able to produce high added value compounds such as lipids and polyunsaturated fatty acids, proteins and essential amino acids, antioxidants and pigments that could be used in several sectors, i.e. food, feed, green chemistry, cosmetical, nutraceutical and pharmaceutical industries and bio-energy field. Nowadays, autotrophic cultivation is the main modality in which microalgae are industrially produced, but its success is limited by factors such as light availability, carbon dioxide supply and high production costs. The main challenge to overcome however is the development of high efficiency strategies for the large-scale production of microalgae at low costs. One possibility to overcome these limits is to exploit the ability of some microalgae species to use organic substrates as a carbon source, i.e. Mixotrophy. Mixotrophy is a metabolic pattern in which microalgae drive both autotrophy and heterotrophy, thus utilizing organic carbon sources as substrates of growth, improving the productivity of the system. Agro-industrial wastes and wastewaters are rich in nutrients and have been widely considered as a potential nutrient source for the cultivation of microalgae. Integration with wastewater treatment is a possible synergy for algal production, where algae may grow on sewages as a water and nutrient source, reducing the total production costs. In Lombardy Region the Agro-food system is one of the most advanced in the whole European Union, and each year it produces huge amount of agro-industrial waste stream. This thesis was focused on the cultivation of some microalgal strains on nutrient rich wastes and is structured in four main chapters. After a general introduction in which are highlighted the possibilities to produce microalgae biomass using agro-industrial wastes through mixotrophic metabolism, in Chapter 2 are shown results of the cultivation of Chlorella sp. and Phaedoctylum tricornutum on livestock wastes, showing the ability to growth and the good depuration performances obtained. The results demonstrated that the microalgal growth was comparable to that attained with standard mineral medium. In Chapter 3, were analyzed the possibilities to growth Chlorella sp. and Nannochloropsis salina on carbon-rich wastes (cheese whey, wine lees, glycerol) sampled from different agro-food activities in Lombardy. Evaluation of the different mixotrophic performances were compared with autotrophy (control) and a macromolecular analysis of the obtained biomasses were performer showing very good results in terms of biomass quantity and quality produced under mixotrophic cultivation. In addition, a Life Cycle Assessment analysis was performed to evaluate the environmental impacts of cultivation of Chlorella sp. grown both autotrophically and mixotrophically. Chapter 4 is devoted to the conclusions where is underline that the microalgae cultivation under mixotrophic conditions could be a viable way to reduce the total production cost of microalgae biomass, increasing the productivity and the quality of the final biomass. On the other hand is very difficult to maintain pure culture without any external contamination, and so lead this production process at industrial scale probably remain far remove from reality.

As anaerobic digestion (AD) is quickly being harnessed in Italy and in other European countries, there is a need for a more in-depth description of the main by-product of the process, the digestate. Little information on digestate characteristics and composition is available and unclear legislation causes problems in biogas plant management. In this work, the organic matter (OM) of this matrix was described through chemical, biological, spectroscopic, and statistical approaches. It was shown that AD results in a strong reduction of the easily degradable fraction of the OM and an accumulation of recalcitrant molecules (possible humus precursors). This contributes to a relatively high biological stability of the residual OM content in the digestate and may lead to good amendment properties. Besides, the observed relative accumulation and the high mineralisation of nitrogen and phosphorus may point to the digestate as a readily available liquid fertiliser for agronomic use. Moreover, xenobiotics and pathogens respected limits for both biosolids and compost in Italian and European legislation.

Questa ricerca si occupa di un ramo della sostenibilità ambientale del controllo delle arvensi infestanti, dal punto di vista del mantenimento e del miglioramento della qualità del suolo. Oggi è disponibile sul mercato una vasta gamma di prodotti e di tecniche, ma la stessa definizione di "pratica sostenibile" non sempre tiene in considerazione la fertilità del suolo. I processi che avvengono nel suolo hanno infatti scale temporali più ampie rispetto a quelli produttivi, commerciali e legislativi. Anche la definizione dei protocolli di indagine è un processo più lento rispetto all'evoluzione commerciale dei metodi di controllo delle infestanti. In seguito ad una pressione esterna, la parte dell'ecosistema suolo che reagisce più velocemente sono gli organismi che in esso vivono, e la comunità microbica è in definitiva l'operatore più efficace nel riciclare i nutrienti del suolo. In questo lavoro gli effetti sul suolo di alcune pratiche di gestione delle infestanti sono stati testati con un protocollo di analisi del suolo standardizzato. Si sono confrontate le variazioni delle proprietà del suolo dopo i diversi trattamenti di controllo delle infestanti. In particolare è stato monitorato il Carbon pool del suolo e come la comunità microbica del suolo lo ricicla. È stato definito un protocollo standard che permette di valutare l'impatto delle pratiche di controllo delle infestanti sia sulle variazioni a lungo termine nella qualità del suolo, sia quelle a breve termine sui processi biologici. L'ipotesi di base è che la gestione delle infestanti possa interagire con i processi di riciclaggio dei nutrienti che avvengono ad opera dei microrganismi che vivono nel terreno. Questi processi hanno un ruolo centrale nel mantenimento della fertilità del suolo, una delle risorse più importanti per l'agricoltura. Sotto particolare attenzione sono le pratiche di gestioni delle infestanti dei frutteti: l'uso di erbicidi sintetici (oxyfluorfene), di erbicidi naturali (oli essenziali ed estratti acquosi) e due metodi meccanici (aratura e pacciamatura). La fertilità del terreno è stata monitorata misurando variabili chimico-fisiche del suolo ed elaborando indici di qualità e bioindicatori. ; This research approaches the question of weed control sustainability, from the point of view of soil quality maintenance and enhancing. A big choice of practices and products for weed control are available nowadays, but the actual definition of "sustainable practice" not always considers soil fertility. Soil processes timescale is wider than the productive, commercial and legislative ones. Also the definition of survey protocols is a process slower than the evolution of weed control methods. The faster reaction in the soil ecosystem after an external pressure is given by the organisms living in it, and the microbial community is finally the most effective agent in nutrient recycling processes. In this investigation, the same soil analysis protocol was applied on soil samples exposed to different weed management and control methods. Using soil quality indexes and bioindicators, soil properties variations after the different weed control treatments were compared. In particular soil carbon pool and how microbial community recycles was surveyed. A standard protocol to both find variations in long-term soil quality and survey the short-term impact of weed control practices on soil biological processes was defined. Weed management practices can interact with the nutrients recycling processes performed by the microorganisms living in the soil. These processes have a central role in maintaining soil fertility, one of the most important resources for agriculture. Three weed management practices were compared: the use of synthetic (oxyfluorfen) or natural (essential oils and aqueous extracts) herbicides and two mechanical methods (tillage and mulching). Soil fertility was monitored measuring soil physical-chemical values and elaborating soil quality indexes and bioindicators.

The object of this thesis is to sustain that achieving Sustainable Development in Aquaculture and Fisheries is not only possible, but also strongly recommendable. Fishing and Aquaculture products are a highly valuable source of protein that remarkably contribute to food security at a global level. They also constitute a source of income and employment, but when ill managed, can cause irreversible depletion of natural aquatic resources.

The consumers have an increasing interest about food traceability with respect to safety, quality and typicality issues. Food traceability is an important issue in food safety and quality control, with impacts on food security, its quantity and overall availability. Furthermore, the possibility of tracing the origin of foodstuff is assuming an increasingly important role at the legislative level, as a tool that may allow to prove on product authenticity and to control adulteration. So, establish systems to trace food products through specified stages of production, processing and distribution play a key role also to ensure food safety. In the last years, several of analytical techniques have been tested to found ways to establish the geographical origin of different kinds of food and many works reported that the combination of different analytical methods associated a multifactorial analysis of the data seems to be the most promising system to establish univocal traceability systems. The honey is a natural food well appreciated in the world and the detection of potential fraud could be favored through tools linking the chemistry composition of this production to producing area. A small number of investigations regarding traceability of honey can be found in the scientific literature. Therefore, in these contest the development of fingerprinting techniques based on the determination of the specific markers of provenance analyzed whit chemometric approach represents an interesting area of research. Recent works have been demonstrated the potentiality of the study of the distribution patterns of rare earth as a promising analytical method for traceability of food products due coherent and predictable chemical behavior of these compounds. Also, have been demonstrated that their distribution in soil keeps unaltered in plants growing on that soil and eventually in agricultural products obtained from those plants and through the normalization of the REEs distribution, it is possible to appreciate their relative enrichments in soil-plant- agro food products The aim of the research was to observe if the REEs normalizated pattern of honey of Sulla (Hedysarum coronarium L.) was kept unaltered respect the soils of production to establish a correlation between geographic area and honey product. For this study, different production areas of Sulla in Sicily were considered. The production fields explored by the bees within 2 km of the hives were taken into consideration, the soil and the flowering plants were sampled. Flowers and leaves were analyzed from the plant. In the hive, pollen and honey were taken in three different days during the flowering period of the Sulla. Of same areas were sampled to the same methods in different periods where other monofloral honeys were product, these samples were used for a control. In this study the REE approach, give very intriguing results in the geographical traceability of honey samples and are the first. The results have been supported by statistical treatment.

COD AND TPH ANALYSIS IN SLOPS EXPERIMENTAL TREATMENT PLANTS: ANALYTICAL PROBLEMS. In the last years, the persistence and accumulation of xenobiotic compounds in the environment created many disposal problems of oily wastewater generated by ships, mainly in engine-rooms (bilge waters) and by cleaning of tanker (slops). The high salinity levels (up to 25.000 mgL-1) and the pollutants concentration, both limit the chances of discharge into the sewer systems and address the disposal of these wastewaters to the sea. For these reasons it is necessary to treat such wastewater efficiently before discharging [1]. As a part of a broader project concerning slops treatments, this work addresses issues related to the analytical methods of the COD and TPH parameters, chosen under the provisions of Italian Legislative Decree 152/06, that implements the European directives on environmental protection. In the COD analysis the greatest difficulty was the high salinity levels corresponding to high chlorides levels. Chlorides cause a positive interference in the measurement, and this interference during the analysis of COD was investigated at various concentrations of mercury in order to try to minimize the use of this reagent that causes many problems of safety and disposal, and at different times reaction [2][3][4]. The major problems in TPH analysis concerned correct setup of the gas chromatographic separation, high variability in sample composition and the high capacity of the sample to form emulsions during the liquid-liquid extraction procedure. This paper reports the results of the analysis of COD and TPH and the problems related to the development of a suitable analytical method for the analysis of these specimens. This study is part of STITAM European project, created with the aim to develop innovative technologies for the treatment of liquid wastes of navigation, in order to better safeguard marine environment. [1] G. Mancini, S. Cappello, M.M. Yakimov, A. Polizzi, M. Torregrossa, Chemical Engineering Transactions 27 (2012) 37-42. [2] I. Vyrides, D.C. Stuckey, Bioresource Technology 100 (2009) 979–982 [3] Alexandra M.E. Viana da Silva, Ricardo J.N. Bettencourt da Silva , M. Filomena G.F.C. Camoes, Analytica Chimica Acta 699 (2011) 161– 169 [4] D.D.C. Freire, G.L. Sant'anna jr, Environmental Technology 19 (1998) 1243- 1247

The fertilizer framework in the European Union has recently been reviewed by EU Regulation 1009/2019 that excluded sewage sludge from the list of the possible constituents of organic fertilizers relying on their origin, not on their quality. This paper aimed to carry out a complete characterization of sewage sludge obtained from a pharmaceutical manufacturing process (PDSS) to demonstrate that sewage sludge obtained from a standardized and controlled manufacturing process can be safely recycled as organic fertilizer. The agronomic and environmental characteristics of the PDSS product were analyzed and compared to other organic fertilizers. Its fertilizing potential was also evaluated through plant growth trials. PDSS was characterized by a high concentration of total N (6.6% w/w), which was all present in organic form. PDSS also showed a low concentration of heavy metals, an absence of pathogens and low concentrations of organic contaminants. Plant growth trials showed that the PDSS was able to improve lettuce and carrot growth (+25 and +46% of dry weight compared to the unfertilized control), as well as their physiological status. Considering all the results, the exclusion of sewage sludge relying only on its origin and not on its quality appears to conflict with the principles of the circular bioeconomy.

Lo scopo della tesi è di caratterizzare i rischi per la salute umana, che derivano dall'inquinamento delle acque (acque sotterranee) e dal cibo (riso) tramite l'applicazione e lo sviluppo di nuove tecniche analitiche. La tecnica "diffusive gradients in thin films (DGT)" con resina a base di ferrihydrite, è stata studiata per l'accumulo delle forme inorganiche (As(III) e As(V)) e organiche (DMA(V) e MMA(V)) di Arsenico in matrici acquose. I DGT sono stati applicati su campioni di acque sotterranee, raccolti in sei diverse città del Nord Italia, dove la concentrazione di As è molto alta. Antimonio (Sb) è associato all'As in diversi studi perché le proprietà fisiche e chimiche di questi due elementi sono simili, ed esso è stato recentemente riconosciuto come contaminante dell'acqua. In questa tesi per la prima volta sono state riportate le prestazioni dettagliate dei DGT con ferrihydrite, impiegati in soluzioni acquose di Sb(III) e Sb(V). L'analisi delle forme chimiche di Sb(III) e Sb(V) in campioni acquosi è stata realizzata con l'applicazione della diluizione isotopica. In generale il riso, a differenza di altri prodotti alimentari di origine terrestre, contiene quantità significative di Arsenico inorganico. L'analisi della speciazione di As è stata realizzata in 70 campioni di riso italiano, rappresentativo di diversi tipi di coltivazione. Le forme più abbondanti nel riso erano As(III) e DMA(V). Inoltre è stato interessante studiare la localizzazione dell'As nel chicco di riso, sottoposto a diversi processi di lavorazione (risone, riso integrale e lavorato con o senza parboiling), perché sia la distribuzione che la presenza delle diverse forme chimiche nel chicco sono fattori chiave che controllano la biodisponibilità del contaminante. La distribuzione dell' As nei chicchi di riso di due varietà (Gladio e Ronaldo) sottoposti a diversi processi, è stato determinato con Laser Ablation ICP-MS. In realtà il contenuto di As era più alto nei chicchi di riso non-parboiled rispetto a quello parboiled. La relazione tra intensità dell'As e le varie parti del chicco di riso ha rivelato che i livelli di As diminuisco dalla parte esterna verso la posizione centrale, mentre i valori di As sembrano essere simili tra la parte media e interna dei non parboiled. ; The aim of this thesis was to explore new analytical techniques as well as to carry out further characterisations of human health risks, which derive from water pollution, in particular groundwater, and food, in particular rice. The prevention of water pollution is an environmental aspect, that includes monitoring of both natural enrichment and outside pollution with routine analysis but also with new techniques, e.g. the application of passive sampling techniques and advanced technologies. The diffusive gradients in thin films (DGT) technique with ferrihydrite adsorbent, has been investigated for the accumulation of different species of Arsenic (As), like Inorganic Species (arsenite and arsenate) and Organic Arsenic (dimethylarsinic and monomethylarsenate) in aqueous matrix. To evaluate the performance of DGT method for accumulation of arsenic species, after deployment in synthetic solutions, DGT devices were carried out on groundwaters collected in six different towns in the North of Italy, where the As concentration is very high. Recently, health effects at arsenic exposures have been observed in areas where levels of inorganic As in drinking water are not excessive. Antimony (Sb) is associated to As in several studies because the physical and chemical properties of these two elements are similar, and it has been recently recognized as water contaminant. In this thesis I reported for the first time detailed performance characteristics of the Fe-oxide gel associated to DGT devices deployed in known aqueous solutions of trivalent and pentavalent Sb. Speciation analysis of Sb(III) and Sb(V) in aqueous samples was performed through extraction and on-line determination of isotope dilution concentration after a chromatographic separation. Generally rice, unlike food products of terrestrial origin, contains significant amounts of inorganic arsenic. Recently some Government Organizations (e.g. EFSA) debated the possibility to set an upper limit for total and inorganic arsenic in rice. Arsenic speciation was realized in 70 Italian rice samples from different representative cultivation conditions. The most abundant forms in rice were As(III) and DMA(V). After that, it was fundamental to investigate the localization of As in rice grains in different processes (raw, brown and milled rice with or without parboiling technique), because both speciation and distribution throughout the grain are key factors controlling bioavailability of the contaminant. The As distribution in rice grains of two varieties (Gladio and Ronaldo) from different processes, was determined by LA-ICP-MS. The distribution of As varied between the various parts of the grains (exterior, medium and interior part). During parboiling, the partial boiling of food as the first step in the cooking process, arsenic might have released from the grain to the boiling water. Thus, parboiling of rice grain may reduce the magnitude of arsenic intake in human body. Actually the As content was higher in non-parboiled rice grain than in parboiled rice. The relationship between As intensities and the different parts of rice grain revealed that As levels decreased from the external part towards the middle position, and then the intensity values seem to be similar between medium and internal part in non parboiled products.

Open burning of agricultural waste is still a common practice as it is a rapid method for waste disposal, although natural biomass, including agriculture residues, can be exploited as a renewable energy source. We assessed the viability and sustainability of using vineyard pruning residues, as wood chips, for energy conversion. Wood chips, obtained from vineyards in the Prosecco DOCG region (Italy), were characterized in terms of chemical composition, calorific value, ash content and humidity. Combustion tests were performed in a medium-size biomass boiler (maximum power 500 kW) to assess the viability of the approach in terms of sustainable steady-state combustion. Primary emissions of both macro- and micro-pollutants were measured to assess the environmental impact. An analytical method was purposely developed for the determination of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) and in three matrices: fly ashes, condensate and gas. The results showed that vineyard pruning residues can be used for energy conversion in medium- and large-scale biomass boilers. Primary emissions of measured pollutants were all below limit values set by current European legislation except for particulate matter, for which current available abatement technologies are required to contain emissions, abatement technologies are required to contain emissions, thus making the use of vineyard pruning residues unsuitable for combustion in domestic appliances where such technologies are not installed. Bottom ashes produced during combustion were also characterized to assess whether they can be recycled in the vineyard as soil amendments/fertilizer. Copper content in combustion ashes exceeded limit values for ashes to be used as fertilizers in agricultural fields for some European countries but not for others, indicating that ashes may need to be disposed as waste.