Fenton and Photo-Fenton like at neutral pH for the removal of emerging contaminants in water and wastewater effluents

[eng] In the last decades, the scientific community has been involved in the research of new kinds of contaminants generally known as of “emerging concern” (CECs). The harmfulness of CECs, even at small concentrations as well as, property of bioaccumulation and persistence, makes them extremely dangerous for the human health. The scientific community is constantly researching about novel treatments able to achieve the removal of these contaminants. Advanced Oxidation Processes (AOPs) are considered one of the most useful treatments to achieve CECs degradation. Among the AOPs, Fenton and photo‐Fenton processes are particularly powerful, cheap and easily managed. Nevertheless, some setting requirements of Fenton processes have limited their application at industrial scale. One of the most important limits is the necessity to operate a tight control of the pH in order to avoid iron precipitation (optimum pH~2.8). Unfortunately, the optimum pH for Fenton reaction is essentially far from the normal values of the wastewater treatment plant (WWTP) effluents. Scientific community is then working on the improvement of the operating conditions of Fenton processes in order to improve the applicability in wastewater treatment. These modifications are essentially focused on the possibility to perform the treatment at circumneutral pH (Fenton and photo‐ Fenton like processes). Fenton like processes can be carried out in heterogeneous or homogeneous way according to the phase of the catalyst into the solution. In this study was firstly confirmed the suitability of Fenton based processes in recalcitrant compounds removal. Fenton, UV‐A photo‐Fenton and UV‐C photo‐Fenton were, in fact, applied for atrazine removal from secondary effluent (SE) of municipal wastewater treatment plant (MWWTP). UV‐A and UV‐C photo‐Fenton allowed remove 50% and 100% of the initial atrazine content respectively. The main objective of this thesis was then the assessment of photo‐Fenton’s suitability for recalcitrant contaminant at circumneutral pH. Thus, homogeneous photo‐Fenton like at neutral pH was applied for sulfamethoxazole (SMX) removal. In order to avoid iron precipitation, chelating agents were used to keep soluble the iron at circumneutral pH. The chelating ability of four chelating agents (ethylenediaminetetraacetic acid‐EDTA, nitrilotriacetic acid‐NTA, oxalic acid and tartaric acid) was tested. Then, once determined the optimum molar ratio L:Fe for iron chelation (1.5:1 for EDTA and NTA, 10:1 for tartaric acid and 20:1 for oxalic acid), their catalytic activity was evaluated when employed in photo‐Fenton like for SMX removal. The highest SMX percentage removal, together with the minimum chelating agents required and the better property of biodegradability and low toxicity, demonstrated the suitability of NTA for the purpose. A further study on the stability of the chelates under reaction was carried out. The operating conditions adopted for the treatment significantly influence the stability of the chelate solution. Thus, in order to proper control the parameter set up the behavior of chelates has been study under thermal, oxidative and photochemical stress. It was demonstrated as the temperature control can represent an interesting tool to extend the chelates lifetime under oxidative and photochemical stress. By adopting different H2O2 doses, a linear correlation between doses and chelate decomposition could be identified. The better suitability of UV‐A irradiation, against UV‐C and Xe lamp, to preserve the iron chelate solution was demonstrated. Moreover, the influence of the influent characteristics on the process efficiency needed to be also considered. Thus, different water matrices were used for the experiments. The efficiency of photo‐Fenton like catalyzed by Fe(III)‐NTA has been compared when applied to different aqueous matrixes (Milli‐Q water, tap water, secondary effluent wastewater and well water). It was demonstrated as the ions content, especially Ca2+ and Mg2+, significantly compromise the process of chelation. High alkalinities and organic matter, instead, mainly influenced the phase of process, when acting as radicals scavengers, reduced the amount available for SMX oxidation. Some strategies were then adopted to promote SMX removal. Between them, Mn2+ mediated photo‐Fenton like showed somehow possibility for improvement. Highest removal rate was in fact exhibited in the first minutes of reaction when adding Mn2+ to the solution in ratio molar Mn:Fe 0.5:1. The conclusive study of the thesis regarded the assessment of the Br‐ presence on the efficiency achievable in recalcitrant compounds removal when applying UV/PS/Fe2+ for removal of benzophenone‐4 (BZ4), nitrobenzene (NB), nitrobenzoic acid (NBA), atrazine (ATZ) and ampicilline (AMP). Br‐ demostrated to be a strong inhibitor in the removal of all the considered contaminants except for NB when, the removal was instead enhanced in bromide containing water

Gaussian Discriminating Strength

We present a quantifier of non-classical correlations for bipartite, multi-mode Gaussian states. It is derived from the Discriminating Strength measure, introduced for finite dimensional systems in A. Farace et al., New. J. Phys. 16, 073010 (2014). As the latter the new measure exploits the Quantum Chernoff Bound to gauge the susceptibility of the composite system with respect to local perturbations induced by unitary gates extracted from a suitable set of allowed transformations (the latter being identified by posing some general requirements). Closed expressions are provided for the case of two-mode Gaussian states obtained by squeezing or by linearly mixing via a beam-splitter a factorized two-mode thermal state. For these density matrices, we study how non-classical correlations are related with the entanglement present in the system and with its total photon number.Comment: 11+6 pages, 4 figure

Inside the secret garden of political parties. Transformations and reactions to primary elections in Italy and France

Primary elections are becoming quite spread within no-US political context. Many political parties in different countries choose to adopt such inclusive methods to select their candidates for general elections. Thus, primary elections have been re-adapted to different political systems, in order to fit with different party’s specific features. This implied a re-definition of the very concept of primary both in terms of procedures and in terms of political meaning. This paper aims to understand the promotion of party primaries in two EU countries: Italy and France. The two countries have implemented open primaries adopting the maximum level of inclusiveness. This paper will focus on the public debate about these two case studies in order to clarify which were the meaning and the political value of the primary contests in 2011 (France) and 2012 (Italy)

Italy and Mozambique: Science, Economy & Society within a History of an Anomalous Cooperation

In this article the authors aim at showing how an “anomalous” international and very intense cooperation between Italy and Mozambique was born. In fact, Italy has not a strong colonial tradition, especially in Mozambique, so it seems interesting to try to understand the reason why this former Portuguese colony has become the Italian most important partner in its cooperation activity. This analysis is based on the main hypothesis related to the birth of international bilateral cooperation: they have been seriously considered in order to explain the origin of this strange relationship, but they cannot completely clarify this particular case. According to the Italian social and political recent history, the privileged relationship with Mozambique is due more to a “bottom up” process than to geo-strategic or economic reasons. The fact that Mozambique had belonged to a weak Western power such as Portugal certainly gave Italy the opportunity to penetrate more easily in this country than in the ones which had been under the strong dominion of France or England. One of the most important results of this “anomalous” cooperation has to be found in the scientific fields (such as geology, architecture, biotechnologies) and in its impact on the development of Mozambique

Residual sludge from dimension stones: characterisation for their exploitation in civil and environmental applications

Abstract Residual sludge coming from dimension stones working plants represents a problem for Stone Industries (cost connected to their landfilling); sludge as such can be used for environmental restoration of derelict land or in cement plants, according to Italian regulation. However it is also possible to think about their systematic treatment for the production of Secondary Raw Materials or "New Products". To individuate possible different applications a geotechnical characterization was conducted on sludge as such and on different mixes. In detail the possibility of using them as products for dumps waterproofing and for land rehabilitation and reclamation is discussed

Remineralization and Stabilization of Desalinated Water

Permeate or distillate from desalination processes is typically void of minerals and alkalinity, inherently acidic and therefore corrosive to water distribution infrastructure. The reintroduction of both minerals and alkalinity is essential for the stabilization of the water before it is sent to consumers making this the last step of the treatment process. Classical water stability is evaluated with respect to its calco-carbonic equilibrium which looks at the balance of calcium hardness, alkalinity and pH to determine whether the water has a tendency to dissolve or precipitate calcium carbonate. The purpose of remineralization processes is replenish the levels of calcium hardness and alkalinity in the water and then adjust the pH to deliver a stable water quality that is safe for human consumption and non-aggressive to water distribution infrastructure

Geometrical bounds on irreversibility in open quantum systems

Clausius inequality has deep implications for reversibility and the arrow of time. Quantum theory is able to extend this result for closed systems by inspecting the trajectory of the density matrix on its manifold. Here we show that this approach can provide an upper and lower bound to the irreversible entropy production for open quantum systems as well. These provide insights on the thermodynamics of the information erasure. Limits of the applicability of our bounds are discussed, and demonstrated in a quantum photonic simulator