Nanopore-filling effect of phenanthrene sorption on modified black carbon.

Black carbon was produced by slow pyrolysis under an oxygen-limited condition at 500 °C, and was modified by some chemical methods (oxidation, hydrolysis, activation, and surface recombination). The modified samples were characterized by using elemental analysis, Fourier transformed infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) surface analysis, Boehm titration, cation exchange capacity(CEC)analysis, CO 2 adsorption analysis, and then used to investigate the sorption behavior of phenanthrene. The results showed that the activation of ZnCl 2 gave a maximum nanopore volume of 96.5 μL/g and a specific surface area of 241 m 2 /g, while the oxidation of NaClO gave a minimum nanopore volume of 63.3 μL/g and a specific surface area of 158 m 2 /g. The FTIR, XPS, and Boehm titration analysis showed that the new oxygen-containing functional groups were introduced during the oxidation treatments of H 2 O 2 and NaClO. The sorption of phenanthrene on all samples was typically nonlinear, and the nonlinear factor ( n ) was negatively correlated with V o , especially with V o at 0–1.1 nm. The sorption parameter (log K OC ) was positively correlated with nanopore volume ( V o ) and specific surface area (SSA). Moreover, the model analysis showed that the nanopore filling was the main sorption mechanism, and molecular sieve effect was observed in the sorption of phenanthrene. [ABSTRACT FROM AUTHOR]