Impact of temperature on the dust/gas partitioning of semi-volatile organic compounds in indoor environments

¹ Scientific and Technical Centre for Building (CSTB), Marne la Vallée, France
² LaSIE UMR 7356, La Rochelle University, La Rochelle, France

^* Corresponding author: Aya Mansouri, aya.mansouri@cstb.fr

Abstract

Semi-volatile organic compounds (SVOCs) are one of the ubiquitous families of indoor air pollutants. They can be found in the gas phase as well as in the adsorbed/absorbed phases including airborne particles and settled dust. The dust/gas partition coefficient, K_d, is the ratio of the SVOC concentrations in the settled dust and the gas phase at the equilibrium state thus is a key parameter for modeling the indoor transport and partitioning of SVOCs. Studies have shown that the value of K_d depends on the temperature, the organic fraction in dust, the dust size and density, etc. For indoor SVOC modeling in the context of climate change, the temperature effect on K_d should be addressed particularly. In the present study, a linear relationship between Log₁₀ K_d and the inverse of temperature was derived for 18 SVOCs including polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). K_d decreases by 91.8 to 99.6% when the temperature rises from 10 to 40 °C. The influence of temperature on K_d and the indoor concentration was estimated for three SVOCs using a validated mechanistic model. The dust phase concentration of the three SVOCs may vary by 1.5 orders of magnitude due to variations in K_d in a temperature range between 10 and 30 °C.