Chamber study on migration of DNOP from the source to dust with accumulation of surface dust

Phthalate esters (PAEs) are widespread in indoor environment and exist in the gas, particles, settled dust and material surfaces. Although PAEs concentrations in dust have been widely reported, few study considered that the formation of dust and migration of PAEs occur simultaneously in indoor environment. This study used an emission chamber with a particle generator to simulate the accumulation of particles into the dust and the migration of PAEs from the sources to the dust. DNOP was selected as target compound. The maximum values of DNOP concentrations in the gas phase, particle phase and settled dust were 0.025 µg/m³, 0.061 µg/m³ and 1244.6 µg/g (dust contact with sources), respectively. K _p was ranging from 7.5×10^-4 m³/µg to 4.4×10^-3 m³/µg and the average value of K_d in dust contact with the sources was approximately 1.2 ×10⁵ m³/g. Significantly higher PAEs concentrations were observed in the dust contact with sources indicating the direct contact plays an important role in mass transfer of SVOCs in dust. However, DNOP in dust was not reach the equilibrium in 13 days, suggesting that the migration of SVOCs was a relatively long process and more time were needed.