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A new composite photocatalyst called POF/TiO2 was prepared from commercial P25 TiO2 and Posidonia oceanica fibers (POF), a biomaterial collected from Tunisia’s beach. The composite material was prepared by a classical sol-gel synthesis and was characterized by different methods. SEM images show a TiO2 layer formed on top of the fibers, which was verified by XRD and XPS. Diffuse reflectance UV-vis spectroscopy shows that the layer has the same optical properties (Eg = 3.0 eV) as bulk P25. The photodegradation of phenol as a model compound was studied under different operating conditions using POF/TiO2 and the results show degradation efficiencies between 4% (100 ppm) and 100% (&lt, 25 ppm) after 4 h of UV-C light irradiation (254 nm) using a POF/TiO2 concentration of about 1 g/L. The composite material showed good stability and could be recycled up to three times.

This book includes over three hundred and seventy-five short papers presented during the second EMCEI, which was held in Sousse, Tunisia in October 2019. After the success of the first EMCEI in 2017, the second installment tackled emerging environmental issues together with new challenges, e.g. by focusing on innovative approaches that contribute to achieving a sustainable environment in the Mediterranean and surrounding regions and by highlighting to decision makers from related sectors the environmental considerations that should be integrated into their respective activities. Presenting a wide range of environmental topics and new findings relevant to a variety of problems in these regions, this volume will appeal to anyone working in the subject area and particularly to students interested in learning more about new advances in environmental research initiatives in view of the worsening environmental degradation of the Mediterranean and surrounding regions, which has made environmental and resource protection into an increasingly important issue hampering sustainable development and social welfare.

In the field of water treatment, catalytic oxidation has been developed around the Fenton reagent (hydrogen peroxide coupled with ferrous iron salt) but this oxidative system has drawbacks. In effect, this system only works in acidic pH. In addition, the Fenton reagent used at room temperature generally offers a partial oxidation of pollutants and is not accompanied by a significant removal of total organic carbon. The WPO process (Wet Peroxide Oxidation) that uses the catalytic activation of peroxide hydrogen at high temperature accelerates the kinetic of degradation reactions. But this method poses problems of cost due to the use of high temperatures reaching 140°C. In clean water, the oxygen is found mainly in the processes WAO (Wet Air Oxidation) which generates a huge investment because of high temperature and pressure (250 to 320 ° C - 50 to 150 bar). This represents a major drawback in the industry. The catalytic oxidation reactions in the presence of métallophthalocyanines described in the literature involve KHSO5 or H2O2 which presents a disadvantage in a field of water depollution. Indeed, for the oxidation of trichlorophenol, adding an organic co-solvent is necessary: The reactions present the inconvenient to be conducted in a mixture acetonitrile / buffer (1 / 3, V / V) and not in an aqueous medium .Therefore, it appears that finding a method for oxidation catalysis involving transition metals and using oxygen under mild conditions of temperature and pressure is a particularly important challenge. During this work, we showed that the synthesis of a catalyst: phthaolocyanine cobalt sulfonated fixed on activated carbon is a simple process that takes place at room temperature. The action of these catalysts has been studied in the oxidation of hexanoic acid by oxygen in normal conditions (20 ° C, 1 atm.). We studied the reaction using two catalysts supported on activated carbon as grains, containingrespectively 12 and 50 μmol / g cobalt. We showed that:• the acid mineralization increases with the degree of grafting. In all cases, 97% of hexanoic acidis removed after 6h.• the behavior of catalysts has been studied through recycling. The catalyst with the lowest contentin cobalt showed an increase of activity during the first four cycles. Such activity is stabilised withapparent values of the fall of total organic carbon (TOC) and chemical demand of oxygen (COD) ofabout 90 %. The increase of cobalt concentration enhances the rate of mineralization (expressed inrelation to TOC eliminate d) from 45 % in the first cycle to 62 % at the third cycle. The loss of cobalt is very low. It is below 0,57 % after six cycles. We have also tested the catalytic action of this system in the succinic acid oxidation, oxalic acid and trichlorophenol. We obtain a quasi total fall of TOC and COD and an important rate of mineralization.All these consistent results, can validate this catalytic system. Especially since the catalyst is inexpensive.

Soils samples were collected at different depths (from 0 to 120 cm) from tree sites of Tunisia (Chott Mariem, Enfidha and Kondar). The minerals and physicochemical properties were analyzed. Then the capacity sorption of phosphorus and ammonium was carried only in the samples collected from the surface depth (0-25cm) using the batch processes. The results showed that most soil samples have a clayey texture. The available of nutriment and heavy metals was different and varied with the sites and depths. The sorption of phosphorus and ammonium was rapid initially and gradually diminished to attain equilibrium. The equilibrium was reached after 72 h for phosphorus sorption and 300mn for ammonium sorption. Also the levels of P adsorbed were; 6.27, 6.84 and 6.92 mg P g−1 and ammonium adsorbed were 5.83, 6.5 and 6.3 mg NH4 + g −1 respectively from the soil Chott Mariem, Enfidha and kondar. Applications of the following kinetics models: pseudo-first-order, pseudo- second-order and Elovich model to the data show that the rates of phosphorus and ammonium sorption were best predicted by the pseudo-second-order kinetic model as seen from the correlation coefficient R2 (≥0.98).