Use of Chrysotile Fibres in the Degradation of Cationic and Nonionic Surfactants in Aqueous Solutions |
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| Authors: | Adriano Fachini Inés Joekes |
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| Institution: | Departamento de Físico Química, Instituto de Química, Universidade Estadual de Campinas – UNICAMP, Campinas – SP, Brasil. |
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| Abstract: | It was previously observed that sodium dodecylbenzenesulfonate (SDBS) is degraded in the presence of chrysotile fibres. A higher catalytic efficiency was obtained than the reported values for TiO2 under the same conditions. Chrysotile, a clay mineral fibre of low cost and relatively abundant, probably acts as a catalyst through an Advanced Oxidative Process (AOP) involving free radical formation. In this work, experiments with non‐ionic – Triton X‐45 (octil‐phenoxy polyethoxy ethanol) – and cationic – Herquat 3500 (alkyl dimethyl benzyl ammonium chloride) – surfactants were carried out. Diluted aqueous solutions (50 ppm) of these surfactants were kept in contact with chrysotile (4.0 g) in the dark at room temperature. The aromatic ring disappearance was followed through the absorbance peaks at 224 nm (Triton X‐45) and 208 nm (Herquat 3500) in the UV spectra. After 4 h, reductions in the surfactant solution concentration of 65.0% and 35.0% were observed for the Triton X‐45 and the Herquat 3500 surfactants, respectively. In both cases, reactions carried out without aeration showed a lower reduction of the aromatic ring concentration (30.0% less) when compared to the values obtained for the systems with airflow. The system containing the non‐ionic surfactant seems to achieve equilibrium after 2 h, what is not observed for the cationic surfactant system. |
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| Keywords: | Chrysotile Degradation Surfactants Wastewater Treatment Water Pollutants |
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