Enrichment of chlorobenzene and o-nitrochlorobenzene on biomimetic adsorbent prepared by poly-3-hydroxybutyrate (PHB)

Poly-3-hydroxybutyrate (PHB) was used as a new material to prepare a biomimetic adsorbent by a modified double emulsion solvent evaporation technique. The enrichment capacities of the adsorbent for the toxic liposoluble organic compounds were evaluated by chlorobenzene (CB) and o-nitrochlorobenzene (o-NCB) with the adsorption isotherms, enrichment factor (EF) and enrichment kinetics. The results showed that Sips isotherm fitted the experimental data better than Langmuir and Freundlich models, as well as the pseudo-second order kinetic model fitted better than the first order model. For CB and o-NCB, the maximum adsorption capacity was 125.99 and 39.56 mg g(-1), while the maximum EF was 1204 and 1149 at 20 degrees C for 36 h, though the specific surface area (BET) of the adsorbent was only 8.45 m(2) g(-1). CB had a higher EF than o-NCB because the hydrophilic group (-NO2) decreases the liposoluble ability of o-NCB. K-ow has a positive correlation with EF, so the organochlorine compounds are liable to be adsorbed by the adsorbent. The results indicated that PHB, even polyhydroxyalkanoates, can be a new biodegradable adsorption material. (C) 2009 Elsevier B.V. All rights reserved.