Synthesis of macro-, meso-, and microporous carbons from natural and synthetic sources, and their application as adsorbents for the removal of quaternary ammonium compounds from aqueous solution

Macro- and mesoporous carbon samples have been prepared from both natural and synthetic sources. These natural and synthetic carbons (along with other microporous samples) have been characterized, with composition, thermal decomposition mode and stability (in inert and oxidizing atmospheres), and surface properties determined in each case. Order of thermal stability, porosity, and surface area have been determined, with carbons prepared from natural and synthetic sources exhibiting different thermal decomposition modes. Differences in surface area were attributed to differences in porosity, based on micropore and total pore volume. The adsorption of a series of quaternary ammonium (QA) compounds, dodecyltrimethylammonium bromide, tetradecyltrimethylammonium bromide, and hexadecyltrimethylammonium bromide, onto macroporous and microporous carbons was also investigated using Fourier transform infrared/attenuated total reflection spectroscopy. QA removal was found to increase with increase in carbon chain length, with results indicating that the nature of the carbon adsorbent (with respect to surface area and microporosity) had little influence on QA uptake. (C) 1998 Academic Press.