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Abstract: Ferula communis (L.), a plant belonging to Apiaceae, is widely present in Sardinia, Italy. Currently, interest in F. communis focuses on the presence of two chemotypes in the wild. One chemotype is poisonous to animals, whereas the other chemotype is non-poisonous. Polyphenol oxidase (PPO) has been extracted and partially purified from the two chemotypes of F. communis. The biochemical characterization of the enzymes showed significant differences. In particular, while the two PPOs were not able to use 6- and 7-hydroxycoumarin as substrates, they showed distinct specificity for 6,7- and 7,8-dihydroxycoumarin. Significant differences in the enzyme behavior towards common PPO inhibitors were also observed. In addition, activation energy and activation energy for denaturation were determined, showing significant differences between FP-PPO and FNP-PPO, particularly for denaturation kinetics. The possible roles of the two PPOs in determining differences in composition and toxicity of the two F. communis chemotypes are also discussed. [Copyright &y& Elsevier]

• SBA-TETA adsorbent has a TETA loading of 134 mg g−1. • Adsorption kinetics is described by the pseudo-second order model. • Adsorption isotherm is described by the Langmuir model. • The maximal adsorbed amounts are 23.9 mg g−1 (Cu2+) and 13.6 mg g−1 (Zn2+). • The adsorption ΔG is -21.7 kJ mol−1 (Cu2+) and −28.4 kJ mol−1 (Zn2+). Mesoporous silica particles, based on SBA-15 matrix, were functionalized with triethylenetetramine (TETA), and characterized by transmission electron microscopy (TEM), small angle X-ray scattering (SAXS), and N 2 -adsorption/desorption isotherms (surface area and pore size distribution). The functionalization of SBA-15 with TETA to obtain SBA-TETA was confirmed by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). SBA-TETA functional material was used for the adsorption of Cu2+ and Zn2+ metal ions from aqueous solutions at pH 4 and T = 298 K. The adsorption kinetics was faster for Zn2+ with respect to Cu2+ ions, and could be described by the pseudo-second order model indicating the chemisorption of the metal ions as the rate-determining step of the adsorption process. Adsorption isotherms at 298 K were carried out, and the experimental data analyzed with Freundlich, Temkin, and Langmuir models. Among the isotherm models, Langmuir gave the best fitting of the experimental data, allowing to quantify the maximal adsorbable amount of Cu2+ (23.9 mg g−1) and Zn2+ (13.6 mg g−1) by SBA-TETA. Moreover, the Langmuir constant, K L , was used to calculate the thermodynamic adsorption constant Ko and the associated ΔGo, namely –21.7 kJ mol−1 and –28.4 kJ mol−1 for Cu2+ and Zn2+ adsorption processes, respectively. These values are better than those reported in similar works, likely due to the superior performance of TETA chelating agent respect to conventional alkyl-amino ligands once grafted on SBA-15 surface. [ABSTRACT FROM AUTHOR]

Abstract: Phenosafranine is a toxic, polluting dye, belonging to the N-phenylphenazinium class, whose inexpensive and environmentally friendly elimination from industrial effluents could be of interest. In this study we report phenosafranine degradation and concomitant decolorization of the corresponding wastewaters by H2O2 oxidation in the presence of 5,10,15,20-tetrakis(4-sulfonatophenyl)-porphine-Mn(III) catalyst immobilized on a modified silica support bearing imidazolyl functionality. Some operational features of the catalytic process are described and a chemical mechanism for the bleaching process is hypothesized. The proposed method was compared to others, based on the use of the oxidizing enzymes such as laccase, horseradish peroxidase, and lignin peroxidase. [Copyright &y& Elsevier]

A fractionation of wheat straw components in a two-step chemical pretreatment is proposed. Hemicelluloses were hydrolysed by dilute sulphuric acid, allowing a substantial recovery of crystalline xylose. Lignin was removed by means of a mild alkaline/oxidative solubilisation procedure, involving no sulphite or chlorine and its derivatives. The use of diluted reagents and relatively low temperatures, was both cheap and environmentally friendly. The pretreated material was nearly pure cellulose, whose enzymic hydrolysis proceeded fast and with high yields, leading to high glucose syrups of remarkable purity. [Copyright &y& Elsevier]