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Different composites panels were prepared using two granulometrys of fibers from date palm petiole (PDPF) and bio-matrix from lignin-glyoxal-resin (LGR). The composites panels were manufactured at different PDPF percentages ranging from 10 to 70 wt%. Mechanical properties of the prepared samples were evaluated by measuring tensile strength, Young`s modulus and elongation. The obtained results showed that the sample made from fibers/thermo pressed resin 50/50 wt% has the best mechanical properties. The increase of the granulometry of the fibers from 250 to 500 µm results in an improvement of the tensile strength and Young`s modulus values. However, the LGR matrix reinforced with PDPF showed high values of water diffusion coefficient when compared to the unreinforced LGR.

The electrochemical oxidation of pesticide, p-methylphenol (PMP) as one kind of pesticide that is potentially dangerous and biorefractory, was studied by galvanostatic electrolysis using boron-doped diamond (BDD) as anode. The influence of several operating parameters, such as applied current density, supporting electrolyte, and initial pH value, was investigated. The best degradation occurred in the presence of Na 2 SO 4 (0.05 M) as conductive electrolyte. After 8 h, nearly complete degradation of p-methylphenol was achieved (95%) using BDD electrodes at pH = 3 and at current density equals 60 mA cm −2 . The decay kinetics of p-methylphenol follows a pseudo-first-order reaction. Aromatic intermediates such as 3-methylcatechol, methylhydroquinone and methylbenzoquinone and carboxylic acids such as maleic, formic, fumaric, acetic, succinic, glyoxylic and oxalic, have been identified and followed during the PMP treatment by chromatographic techniques. From these anodic oxidation by-products, a plausible reaction sequence for PMP mineralization on BDD anodes is proposed.

The indigo carmine (IC) is an anionic dye usually used in the textile, food, paper and cosmetic industries. It is one of the most common dyes in wastewater discharged from industries (Hu et al. J Environ Manage 166: 512–518, 2016). Discharge of indigo carmine into the environment may cause skin and eye irritations, injury to cornea and conjunctiva, dermatitis and cancer in humans.

Two titanium phosphate materials (T p P and T h P) have been successfully synthesized by sol-gel route with controlled precipitation and hydrolysis. The T p P material was obtained from the reaction between precipitated titania and phosphate buffer solution H2PO 4 − /HPO 4 2− (pH = 7.3). The T p P material was prepared through hydrolysis of titanium in the presence of H2PO 4 − /HPO 4 2 . The probable state of the phosphate anions in titania framework and their effect on the anatase-to-rutile transformation were characterized by ICP-AES, DTA-TG, 31P NMR, FT-IR, and Raman analysis HRTEM/SEM. FT-IR and 31P NMR analyses of titanium phosphate T p P calcined at low temperature showed that the phosphate species existed not only as Ti-O-P in the bulk TiO2 but also as amorphous titanium phosphates, including bidentate Ti(HPO4)2 and monodentate Ti(H2PO4)4. Increased calcination temperature only gave an enrichment of bidentate structure on the titania surface. For the T p P material, H2PO 4 − /HPO 4 2− anions were introduced into the initial solution, before precipitation, what promoted their lattice localization. At high temperatures, all the phosphorus inside the bulk of TiO2 migrated to the surface. The Raman analysis of both samples showed that the bidentate phosphates increased the temperature of the anatase-to-rutile phase transformation to more than 1000 °C with the formation of well crystalline TiP2O7 phase. This phenomenon was more evident for T p P sample.

The electrochemical oxidation of pesticide, o-nitrophenol (ONP) as one kind of pesticide that is potentially dangerous and biorefractory, was studied by galvanostatic electrolysis using boron-doped diamond (BDD) as anode. The influence of several operating parameters, such as applied current density, supporting electrolyte, and initial pH value, was investigated. The best degradation occurred in the presence of Na2SO4 (0.05 M) as conductive electrolyte. After 8h, nearly complete degradation of o-nitrophenol was achieved (92%) using BDD electrodes at pH 3 and at current density equals 60 mA cm(-2). The decay kinetics of o-nitrophenol follows a pseudo-first-order reaction. Aromatic intermediates such as catechol, resorcinol, 1,2,4-trihydroxybenzene, hydroquinone and benzoquinone and carboxylic acids such as maleic glycolic, malonic, glyoxilic and oxalic, have been identified and followed during the ONP treatment by chromatographic techniques. From these anodic oxidation by-products, a plausible reaction sequence for ONP mineralization on BDD anodes is proposed.