VOLATILIZATION AND SORPTION OF DIMETHYLSILANEDIOL IN SOIL

摘要

Our previous studies showed that dimethylsilanediol (DMSD) was the main hydrolysis product of silicone (polydi-methylsiloxane) polymer in soil. In the present study, volatilization of ~(14)C-DMSD from soil (1 mg kg~(-1)) was investigated in open tubes, with weekly remoistening. Losses of ~(14)C from Londo sandy clay loam and Pipestone sand were about 3.6 and 7.7% wk~(-1), respectively, and were attributed mostly to volatilization. For select samples, DMSD was trapped and identified as the volatilized compound. From 12 soils of variable properties, losses ranged from 1.4 to 6.4% wk~(-1), with higher rates correlated with sandier textures. An estimated K_d of 0.1 L kg~(-1) in wet soil suggests potential mobility of DMSD, but increased bonding with soil drying means that mobility will be retarded under field conditions. Results suggest that volatilization will be a major route of loss of DMSD from soil.