Effetti dello stress termico sugli oli alimentari

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Mainstream deammonification reac-tor at low DO values and employing granular biomass.

Nitrogen removal from wastewater has been exstensively addressed by scientific literature in recent years; one of the most widely implemented technologies consists of the combination of partial nitritation and anaerobic ammonium oxidation (ANAMMOX). Compared to traditional nitrification and denitrification techniques such solution eliminates the requirement for an external carbon source and allows for a reduced production of excess sludge; furthermore, it brings down the costs associated to aeration by 60-90% and the emissions of CO2 by 90%. Similar techniques can turn out to be particularly interesting when stringent environmental regulations have to be met. At present, most of the dedicated research dwells on wastewater at high temperatures, high nitrogen loads and low organic content, as it is typical of sidestream effluents; this project, instead, is focused on mainstream wastewater, characterized by lower temperatures and nitrogen content, but higher COD values. At the center of the thesis is the application of a one-stage reactor treating synthetic mainstream municipal wastewater. The chosen approach consisted in maintaining low DO values, allowing for both for the establishment of a proper reaction environment and for the out-selection of nitrite oxidizers; granular biomass was employed for the experiment, aiming at effective biomass retention. The HRT value was gradually decreased, with a minimum at 6 hours. Resulting nitrogen removal rates proved to be satisfactory, with a maximum TN removal efficiency of 54%. Retention of biomass was also positively enhanced throughout the experiment, and yielded a final SRT value of 15.6 days. The whole process was then inserted into a more complete framework, accounting for possible energetic optimizations of similar treatment plants. Employing COD fractionation as a primary step paves the way for anaerobic digestion side processes, which can produce methane and ultimately provide energy for the main nitrogen removal step. Therefore, envisioning energy-sufficient water treatment processes seems a more and more feasible and realistic possibility

Fabrication of gold nanoantennas on SiO2/TiO2 core/shell beads to study photon-driven surface reactions

Plasmonic nanoantennas offer exciting perspectives for promoting and investigating light-driven chemical reactions. In particular, core/shell semiconductor beads coupled to gold nanoantennas represent an ideal platform for a systematic evaluation of multiple processes stimulated by light at different frequencies. Here we report the detailed fabrication of gold bowties on SiO2/TiO2 core/shell micro- and nano-beads, which is based on the combination of colloidal synthesis, atomic layer deposition and a modified version of induced deposition mask lithography. The critical steps of fabrication, including choice of mask material, etching rate and experimental setup are analyzed and strategies to pursue a successful fabrication of different nanoantennas are discussed