Absorption of polycyclic aromatic hydrocarbons to cellulose

Polycyclic aromatic hydrocarbons (PAHs) are widespread toxic chemicals. The environmental fate of these chemicals is in part controlled by sorption to (organic matter in) sediments and soils. One of the most abundant organic matter compounds on earth is cellulose. Remarkably, sorption of PAHs to cellulose has hardly been studied; only two reports on the binding of some low-molecular-weight PAHs exist in the literature. In this study, sorption of PAHs to cellulose was investigated in more detail, by measuring isotherms for a series of 13 PAHs, covering a wide hydrophobicity range. The results indicated that sorption of PAHs to cellulose is a linear partition process for all PAHs investigated (phenanthrene-indeno[1,2,3-cd]pyrene). The affinity of PAHs for cellulose appeared to be about 400 times lower than for octanol and even up to 300 000 times lower than for black carbon or coal. Linked to the estimated yearly production of cellulose and black carbon, these results suggest that cellulose is probably not a major environmental sorption domain for PAHs.