| This study is aimed to develop new heterogeneous catalyst (SBA-15is chosen as the support) for the elimination of persistent organic pollutants by different types of AOPs, typically classified to two main parts:hydrogen radicals based and sulphate radicals based. The selected catalyst support is SBA-15type mesoporous silica supported with iron and/or copper oxides. Iron and copper-based catalyst is mostly used in heterogeneous AOPs systems as efficiently active sites to produce free radicals. As the first step, the preparation methods would play a great role in the dispersion and particle size of supported species which affect the catalytic activity. Secondly, taking into account the characters of silica support, such as the pore size and pore volume, main reactions are proposed. This step allows determining the catalytic activity of iron and copper oxides supported on SBA-15in CWPO process and in integrated sono-photo Fenton process. The reaction parameters are fully investigated as well as the intermediates produced during the reaction which deduced the proposed reaction pathways for organic pollutants (e.g. phenol and AO7). Meanwhile, the effect of second metal supported on the SBA-15host matrix is also investigated. Subsequently, fully catalytic activity by using CWPO process is developed. The combination of electrochemical and heterogeneous sulphate-based process of pharmaceutical compounds is undertaken. At this part, the efficiency of the new process compared to the individual process and possible degradation pathways are investigated.1) CuO/SBA-15catalysts were prepared using different routes, including incipient wetness impregnation method (I), in situ auto-combustion (AC), deposition precipitation (DP), and modified direct synthesis (DS). The materials obtained from these different routes were characterized by XRD, BET, TEM, FTIR, UV-vis and TPR. Their performances evaluated for the phenol oxidation by heterogeneous Fenton-like process. The difference of interaction between the active phase and the silica hot support, through the material stability in reaction, was observed, as well as the effect of the copper particle size and dispersion on the activity. The study is focused on the effects of CuO/SBA-15preparation route on the dispersion and stability of active species on the SBA-15host matrix. The results showed that the catalytic activity of the CuO/SBA samples was influenced by the copper dispersion. The mesoporous structure of DP-CuO/SBA sample has been partial damaged with the presence of bulker copper particles. Uniform and small copper nanoparticles can be prepared by direct synthesis and modified impregnated method using glycine. All the samples can achieve almost complete removal of phenol, expect the impregnated samples. In addition, further research on deactivation and regeneration of these catalysts is in progress.2) Mesoporous SBA-15silica supported copper nanoparticles materials were synthesized via a simple and efficient procedure involving the impregnation of a glycine-nitrate complex on preformed silica, followed by combustion step. Different copper loading were prepared in silica presenting different pore diameter and micropore fraction in order to achieve highly dispersed copper nanoparticle formation either in the mesopores or in the micropores. The effects of the operational parameters were carefully analyzed in phenol oxidation using hydrogen peroxide in ambient conditions to evidence the positive effect of the heterogeneisation of the process, effects of copper loading, and especially the localization of copper nanoparticles (in micropores or in mesopores), was investigated and discussed. Furthermore, the stability of the copper active species, which is also a crucial parameter, was also evaluated.3) A series of FeCu bimetallic supported SBA-15with different copper/iron ratio were prepared using a simple impregnation method, and used as the heterogeneous Fenton catalyst in the degradation of phenol. XRD, ICP-OES, FTIR, UV-vis and TPR were used to evaluate the structural and textural properties of the catalyst coupled with the dispersion of metal species. The main objective of this study is to demonstrate the catalytic activity of phenol over the bimetallic catalyst consisting of Cu and Fe supported on SBA-15with different molar ratios in a wide pH range. The metal leaching has also been investigated to assess the stability of the developed catalyst in order to avoid the secondary metal leaching contamination. The bimetallic catalyst with Cu/Fe molar ratio exhibited much better catalytic activities than the monometallic catalyst due to the interaction of the two metal ions on the surface of matrix silica and it is pH-insensitive and stable which can maintain active over a wide pH range and several recycle runs.4) AO7degradation was studied over integrated sono-photo-Fenton process using Fe2O3/SBA-15as heterogeneous catalyst. The main purpose of this work was to evaluate the ability of a mesoporous SBA-15supported nanosized Fe2O3particles (Fe2O3/SBA-15) to behave as efficient and stable catalyst in AO7oxidation using heterogeneous sono-photo-Fenton process in ambient conditions. Our study also addressed the combination of heterogeneous Fenton-like catalyst with the integrated technology of ultrasound and UV irradiation, and the influence of operating reaction conditions, such as organic pollutant and hydrogen peroxide concentration, initial pH, ultrasonic power and catalyst loading. The change of particle size of Fe2O3/SBA-15before and after reaction was also explored and the intermediate reaction products monitored by GC-MS analyses, so as to propose the AO7degradation reaction pathway by various heterogeneous Fenton-based systems.5) Bimetallic oxides supported on mesoporous silica (Fe-Cu-SBA-15) was prepared and used as heterogeneous catalyst for the oxidation of clofibrie acid in neutral aqueous medium. This process is focused on the catalytic activity of heterogeneous activation of peroxydisulfate (PDS) enhanced by electrochemical process. The influence of various parameters were studies and described in details, including the initial pH, current density, PDS and catalyst concentration. The results showed that the use of heterogeneous catalyst not only increases the removal efficiency of the process, also presents the pH insensitive character in the range of3-9. Almost complete removal of clofibrie acid was obtained due to the production of sulfate free radicals. The catalytic performance was evaluated in terms of total organic carbon (TOC) conversions and metal leaching into the aqueous solution. The main reaction intermediates were separated and identified using GC-MS and a possible clofibric acid degradation pathway was proposed. The heterogeneous catalyst performance in the Electro/PDS process demonstrates a high degradation efficiency of clofibric acid, which would be considered as a promising treatment process. |
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