VOLATILIZATION AND SORPTION OF DIMETHYLSILANEDIOL IN SOIL

Abstract

Our previous studies showed that dimethylsilanediol (DMD) was the main hydrolysis product of slicone (polydimethylsiloxane) polymer in soil. In the present study, volatilization of 14C-DMSD from soil (1 mg kg−1) was investigated in open tubes, with weekly remoistening. Losses of 14C 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 Kd 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.