The aim of this study was to degrade theophylline (TP) drug in a pharmaceutical effluent solution utilizing persulfate (PS). A simulated and a real effluent solution were used, with different conditions tested to optimize the degradation process. HPLC analyses and a modified-HPLC method were used to track concentrations of TP and PS respectively in the treatment process.
View Article and Find Full Text PDFDegradation of PPCPs by AOPs has gained major interest in the past decade. In this work, theophylline (TP) oxidation was studied in thermally (TAP) and chemically (CAP) activated persulfate systems, separately and in combination (TCAP). For [TP] = 10 mg L, (i) TAP resulted in 60% TP degradation at [PS] = 5 mM and = 60 °C after 60 min of reaction and (ii) CAP showed slight degradation at room temperature; however, (iii) TCAP resulted in complete TP degradation for [PS] = [Fe] = 2 mM at = 60 °C following a pseudo-first order reaction rate with calculated = 5.
View Article and Find Full Text PDFHO is one of the most commonly used oxidants for the degradation of recalcitrant organic contaminants in advanced oxidation processes (AOPs). However, most research aiming to optimize AOPs is missing the monitoring of the remaining HO, an important parameter to assess the efficiency of the process. In this work, a novel method for [HO] quantification was developed using simple modifications of an HPLC-DAD setup that is available in most analytical chemistry laboratories.
View Article and Find Full Text PDFExisting analytical techniques used for the quantification of persulfate (PS) in water mostly rely on polarography, reductometry or spectrophotometry. Although acceptable to a certain extent, these methods did not satisfy environmental chemists seeking rapid, reproducible and accurate quantification of PS upon the application of ISCO and AOPs technologies. Accordingly, a novel flow injection/spectroscopy analytical technique is developed via the use of an HPLC coupled to bypass capillary columns and a DAD detector.
View Article and Find Full Text PDFThe increase in demand for, and disposal of, pharmaceuticals, positively correlated with the growing human population, has led to the emergence of contaminants with high environmental and health impacts. Several developing countries that endure problems related to water sufficiency and/or quality resort to the use solar stills as an affordable water treatment method. This research is aimed at investigating the fate of five chemically distinct pharmaceuticals that might pervade solar stills; ibuprofen (IBU), diclofenac (DCF), carbamazepine (CBZ), ampicillin (AMP) and naproxen (NPX).
View Article and Find Full Text PDFJ Hazard Mater
October 2010
The aqueous removal of diclofenac (DF) by micrometric iron particles (Fe(0)) and amended Fe(0) (Me(0)(Fe(0))) under oxic and anoxic conditions was investigated. Bimetallic systems were obtained by plating the surface of Fe with Co, Cu, Ir, Ni, Pd and Sn. Experimental results confirmed the superiority of (Me(0)(Fe(0))) for DF removal except for IrFe (oxic) and SnFe (anoxic).
View Article and Find Full Text PDFSince the introduction of iron wall technology, the inherent relationship between contaminant removal and iron corrosion has been mostly attributed to electron transfer from the metal body (direct reduction). This thermodynamically founded premise has failed to explain several experimental facts. Recently, a new concept considering adsorption and co-precipitation as fundamental contaminant removal mechanisms was introduced.
View Article and Find Full Text PDFZerovalent iron powder (ZVI or Fe(0)) and nanoparticulate ZVI (nZVI or nFe(0)) are proposed as cost-effective materials for the removal of aqueous antibiotics. Results showed complete removal of Amoxicillin (AMX) and Ampicillin (AMP) upon contact with Fe(0) and nFe(0). Antibiotics removal was attributed to three different mechanisms: (i) a rapid rupture of the beta-lactam ring (reduction), (ii) an adsorption of AMX and AMP onto iron corrosion products and (iii) sequestration of AMX and AMP in the matrix of precipitating iron hydroxides (co-precipitation with iron corrosion products).
View Article and Find Full Text PDFAttenuated total reflection Fourier transformed infrared spectroscopy (ATR-FTIR) can be successfully used for the quantitative determination of small amounts of pollutants like the organic fraction of aerosols. The relation between sample concentration and reflectance is described by the Kubelka-Munk equation and was found to be linearly proportional to the absorption band of some functional group. Several parameters like the matter of solid matrix, the cleaning of the sampling support, the treatment of reflectance spectra and the base line correction considerably influenced the reflectance spectra and facilitated data interpretations.
View Article and Find Full Text PDFPalladium, ruthenium and silver were investigated as catalysts for the dechlorination of dichlorophen (DCP, 2,2'-methylenebis(4-chlorophenol)), an antimicrobial and anthelmintic agent largely used as algicide, fungicide and bactericide. Experiments were undertaken under oxic and anoxic conditions for experimental durations up to 180 min (3h). The anoxic conditions were achieved by purging the solutions with nitrogen gas.
View Article and Find Full Text PDFModified zero valent iron (MZVI) was used to study the transformation of a chlorothalonil (CLT) solution and the variation of the observed degradation rate of the reduction reactions. This was carried out when transition metals e.g.
View Article and Find Full Text PDFA study of the effect of zero-valent iron (ZVI) powder is carried out for the first time on the degradation of flutriafol ((RS)-2,4'-difluoro-alpha-(1H-1,2,4-triazol-1-ylmethyl)-benzhydryl alcohol, C(16)H(13)F(2)N(3)O), a bifluorinated soil and water persistent triazole pesticide using a laboratory scale device consisting of a 20 ml pyrex serum vials fixed to a Vortex agitator. Different amounts of ZVI powder (10-50 g l(-1)) at pH 6.6 and room temperature were investigated.
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