While activated sludge treatment is currently the preferred process for the removal of tributyl phosphate (TBP) at the mg.L level, it is well known that this recalcitrant molecule is incompletely degraded, stimulating research into alternative approaches, such as advanced oxidation. The aim of this study was to characterize the degradation mechanism of TBP during ultraviolet/HO treatment using P NMR, ionic chromatography and total organic carbon analysis.
View Article and Find Full Text PDFIntensive use of chlorinated pesticides from the 1960s to the 1990s has resulted in a diffuse contamination of soils and surface waters in the banana-producing areas of the French West Indies. The purpose of this research was, for the first time, to examine the degradation of two of these persistent pollutants - chlordecone (CLD) and beta-hexachlorocyclohexane (β-HCH) in 1 mg L synthetic aqueous solutions by means of photolysis, (photo-) Fenton oxidation and ozonation processes. Fenton oxidation is not efficient for CLD and yields less than 15% reduction of β-HCH concentration in 5 h.
View Article and Find Full Text PDFOxidative regeneration of activated carbon (AC) exhausted with phenolic compounds is still a challenging issue due to the frequent porosity loss. Addition of low HO amount is investigated as a way to promote catalytic wet air oxidation (CWAO) of adsorbed pollutants and thereby to recover absorbent properties. Commercial AC and transition metal (iron or copper)-modified counterparts are tested in repeated adsorption/batch peroxide-promoted CWAO of phenol.
View Article and Find Full Text PDFTwo sonochemical processes were compared for the removal of ibuprofen in different water matrixes (distilled water and effluent from wastewater treatment plant). The effect of various operating parameters, such as pH (2.6-8.
View Article and Find Full Text PDFWater-borne phosphine-functionalized core-cross-linked micelles (CCM) consisting of a hydrophobic core and a hydrophilic shell were obtained as stable latexes by reversible addition-fragmentation chain transfer (RAFT) in water in a one-pot, three-step process. Initial homogeneous aqueous-phase copolymerization of methacrylic acid (MAA) and poly(ethylene oxide) methyl ether methacrylate (PEOMA) is followed by copolymerization of styrene (S) and 4-diphenylphosphinostyrene (DPPS), yielding P(MAA-co-PEOMA)-b-P(S-co-DPPS) amphiphilic block copolymer micelles (M) by polymerization-induced self-assembly (PISA), and final micellar cross-linking with a mixture of S and diethylene glycol dimethacrylate. The CCM were characterized by dynamic light scattering and NMR spectroscopy to evaluate size, dispersity, stability, and the swelling ability of various organic substrates.
View Article and Find Full Text PDFThis work aimed at understanding the combined effect of sludge pH, temperature, and external pressure on the efficiency of sewage sludge ultrasound (US) pretreatment. Based on the evolution of both the degree of sludge disintegration (DDCOD) and pH, application of 40 mgNaOH/gTS during 30 min was selected for chemical pretreatment. Mechanical and thermal effects induced by cavitation contributed in similar proportion to sludge disruption, but the role of the latter effect tended to be weakened after mild alkalisation of sludge.
View Article and Find Full Text PDFWell defined star copolymers have been prepared by copper-catalyzed atom transfer radical copolymerization of styrene and styryldiphenylphosphine starting from a modified Boltorn™ H30 multifunctional initiator. These polymers and an analogue obtained by debromination of the arm ends with nBu3SnH have been used in combination with [Rh(acac)(CO)2] for the homogeneous phase hydroformylation of 1-octene.
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