2010 journal article
Factors Controlling Alkylbenzene and Tetrachloroethene Desorption from Municipal Solid Waste Components
ENVIRONMENTAL SCIENCE & TECHNOLOGY, 44(3), 1123β1129.
Desorption rates of toluene, o-xylene and tetrachloroethene from individual municipal solid waste components [high-density polyethylene (HDPE); poly(vinyl chloride) (PVC); office paper; newsprint; and rabbit food, a model food and yard waste] were determined. Effects of sorbent and sorbate properties, solvent composition (ultrapure water, acidogenic and methanogenic leachates), and contact time (βagingβ) on desorption rates were evaluated. Hydrophobic organic contaminant (HOC) desorption from PVC and HDPE could be described with a single-parameter polymer diffusion model. In contrast, a three-parameter, biphasic polymer diffusion model was required to describe HOC desorption rates from biopolymer composites. In general, HOC desorption rates from plastics were rapid for HDPE (D = 10β10 cm2/s), a rubbery polymer, but slower for PVC (D = 10β13β10β14 cm2/s), a glassy polymer. For biopolymer composites, a large fraction of sorbed HOCs was rapidly released (Dr = 10β9β10β10 cm2/s) while the remaining fraction desorbed slowly (Ds = 10β11β10β16 cm2/s). The toluene desorption rate from PVC was 1 order of magnitude faster in acidogenic leachate than in either ultrapure water or methanogenic leachate, a result that was primarily attributed to the plasticizing effect of volatile fatty acids in acidogenic leachate. For biopolymer composites, small increases in the slowly desorbing HOC fraction were observed with increasing aging time.