Chlorophenols in water

Fire protection - Fire extinguishing media - Halogenated hydrocarbons. Code of practice for safe handling and transfer procedures. Supersedes BS 6535 Section 2.2 1989 Water quality - Gas chromatographic determination of some selected chlorophenols in water. Also BS 6068-2.65 1999... 

Nagata Y, Nakagawa M, Okuno H, Mizukoshi Y, Yim B, Maeda Y (2000) Sonochemical degradation of chlorophenols in water. Ultrason Sonochem 7 115-120... 

Sonolytic decomposition of chlorophenol in water was enhanced in the presence of Fe(II), assuming that the Fenton oxidations occur ... 

Liu, J.-F., J.A. Jonsson, and P. Mayer. 2005. Equilibrium sampling through membranes of freely dissolved chlorophenols in water samples with hollow fiber supported liquid membrane. Anal. Chem. 77 4800M-809. ... 

Jin, M. and Y. Yang. 2006. Simultaneous determination of nine trace mono- and di-chlorophenols in water by ion chromatography atmospheric pressure chemical ionization mass spectrometry. Anal. Chim. Acta 566 193-199. 

Ragaini, V., Selli, E., Bianchi L.C. and Pirola C. (2001) Sono-photocatalytic degradation of 2-chlorophenol in water Kinetic and energetic comparison with other techniques. Ultrason. Sonochem. 8,251-258. 

Chapter 7 reports a scaling-up procedure for photocatalytic reactors. The described methodology uses a model which involves absorption of radiation and photocatalyst reflection coefficients. The needed kinetics is obtained in a small flat plate unit and extrapolated to a larger reactor made of three concentric photocatalyst-coated cylindrical tubes. This procedure is applied to the photocatalytic conversion of perchloroethylene in air and to the degradation of formic acid and 4-chlorophenol in water. 

Lin, C.Y. and Huang, S.D. Application of liquid-hquid-hquid microextraction and ion-pair liquid chromatography coupled with photodiode array detection for the determination of chlorophenols in water. J. Chromatogr. A. 2008, 1193, 79-84. 

Tabai, S., Rogalski, M., Solimando, R., Malanowski, S.K. (1997) Activity coefficients of chlorophenols in water at infinite dilution. J. Chem. Eng. Data 42, 1147-1150. 

Liu J-F, Liang X, Chi Y-G, et al. High performance hquid chromatography determination of chlorophenols in water samples after preconcentration by continuous flow hquid membrane extraction on-hne coupled with a precolumn. Anal. Chim. Acta 2003 487 129-135. 

The formation of chlorophenols in water supplies can create severe odor and taste problems. The chlorination of phenols has already been described in Section 11.5. As has been shown in Figure 11.14, the reactants are HOCl (more electrophile than OCl ) and phenolate (PhO ) (a better nucleophile than phenol (PhOH)). 

EN Standard (1999a) Water quality - gas chromatographic determination of some selected chlorophenols in water, EN 12673 1999. 

Ill. Sojo, L. E. and Djauhari, J., Determination of chlorophenolics in waters by membrane solid-phase extraction comparison between Cig and activated carbon membranes and between modes of extraction and elution, J. Chromatogr. A, 840, 21-30, 1999. 

Al-Sayyed, G., D Oliveira, J. C. and Pichat, P, 1991, Semiconductor - sensitized phot-degradation of 4-chlorophenol in water, J. Photochem. Photobiol. A Chem., 58 99-114. 

Table III. Effect of pH on Photolysis of Chlorophenols in Water a 2,4-Dichlorophenol ...

I. Manet, S. Monti, R Bortolus, M. Fagnoni, A. Albini, The photochemistry of 4-chlorophenol in water revisited the effect of cyclodextrins on cation and carbene reactions, Chem. Eur. J., 2005, 11, 4274-4282. 

Methods such as standard addition only provide good results with a relatively simple matrices. One of the main problems when a first-order multivariate model is used is the presence of unknown interferences. Mathematical models have become very important for solving this problem an example is the determination of five pollutants of the chlorophenol family in urine. The effect of the matrix is minimized by including, in the calibration step, standard samples containing the analytes in the presence of the interfering matrix. The calibration set includes 60 standard samples 50 samples of chlorophenols in water and 10 of lyophilized urine. 

Hirai et al. have developed MlPs containing rose bengal (RB) as a photosensitizer." These polymeric sensitizers were found to promote the selective oxidation of the target chlorophenol in water with molecular oxygen under visible light irradiation (X > 530 nm). Using chlorophenols as the template molecules, polymerization of MAA as a functional monomer furnished the active MlPs (Scheme 17). 

Some studies reported enhancements in photoactivity in the presence of a small amount of rutile phase [122-124]. Even a mechanical mixture of anatase and rutile showed much higher photoactivity for naphthalene oxidation than either pnre anatase or rutile powders [123,124]. The P25 powder is produced from TiCl4 in a flow reactor [122]. Based on a detailed investigation by x-ray diffraction (XRD) and micro-Raman spectroscopy, the rutile (formed directly in the flame) was fonnd to be covered by anatase [122,124]. However, another study based on transmission electron microscopy (TEM) with selected-area electron diffraction reported the presence of separate particles of anatase and rutile in P25 [125,126]. Diffuse reflectance spectra of P25 could be reproduced by a mechanical mixture of anatase and rutile powders, and particles of pure rutile phase were isolated from P25 upon HF treatment. Photoactivity for the decomposition of 4-chlorophenol in water was compared on four commercial photocatalysts, applying criteria of (a) initial rate of pollutant disappearance, (b) amount of intermediate products formed, and (c) time necessary to achieve total mineralization [127]. Based on criterion (c), P25 was concluded to be the most efficient photocatalyst even though it contains 20% rutile and has a moderate BET surface area (ca. 50 m /g). It was also reported to have a higher photoactivity than catalyst All in the degradation of reactive black 5 (an azo-dye) [128]. 

Hollow fiber-based extraction can be used for the determination of freely dissolved phenols or total concentration of phenols in environmental water samples. Liu et al. [199] applied hollow fiber-based supported liquid membrane (SLM) coupled with HPLC to the determination of freely dissolved chlorophenols in water samples. In this equilibrium sampling through membranes, freely dissolved chlorophenols were successfully determined in model solutions of humic acids and at low-ppb levels in river and leachate waters. 

Moradi M,Yamini Y, EsrafiliA, Seidi S (2010) Application of surfactant assisted dispersive liquid-Uquid microextraction for sample preparation of chlorophenols in water samples. Talanta 82 1864-1869. doi 10.1016/j.talanta.2010.08.002, ISSN 0039-9140 Moriwakia H, Harino H, HasMmoto H, Arakawa R, Ohe T, Yoshikura T (2003) Determination of aromatic amine mutagens, PBTA-1 and PBTA-2, in river water by solid-phase extraction followed by liquid chromatography-tandem mass spectrometry. J Chromatogr A 995 239-243. doi 10.1016/S0021-9673(03)00514-4... 

Pichat P, Khalaf H, Tabet D, Houari M, Saidi M (2005) Ti-montmorillonite as photocatalyst to remove 4-chlorophenol in water and methanol in air. Environ Chem Lett 2(4) 191-194... 

---