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Adsorption of phthalates by activated sludge and its biopolymers
Herbert H P Fang1, Hehui Zheng
1Centre for Environmental Engineering Research, Department of Civil Engineering The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China.
Abstract:
This study shows diethyl phthalate (DEP) and dibutyl phthalate (DBP) were substantially adsorbed by activated sludge and its extracellular polymeric substance (EPS). The adsorption characteristics followed Freundlich and Langmuir isotherms. According to the Langmuir isotherm, each gram of activated sludge at maximum adsorbed 0.73 mg of DEP and 17.6 mg of DBP, and each gram of centrifugation-extracted EPS adsorbed 14.3 mg of DEP and 10.6 mg of DBP. The adsorption increased with the hydrophobicity of phthalates. This suggests most phthalates, which are of higher hydrophobicity than DEP and DBP, are likely to be removed from wastewater through adsorption by the activated sludge in the biological treatment process.
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Types of Step-Growth Polymers: Polyesters
Polyesters are commonly prepared from terephthalic acid and ethylene glycol; the crude product is known as poly(ethylene terephthalate) or PET. However, polyesters are synthesized industrially by transesterification of dimethyl terephthalate with ethylene glycol at 150 °C. The two reactants and the polymer...

