Water, Air, and Soil Pollution

, Volume 87, Issue 1, pp 231–243

Fate of sludge-applied silicones in agricultural soil microcosms

  • R. G. Lehmann
  • C. L. Frye
  • D. A. Tolle
  • T. C. Zwick
Article

DOI: 10.1007/BF00696839

Cite this article as:
Lehmann, R.G., Frye, C.L., Tolle, D.A. et al. Water Air Soil Pollut (1996) 87: 231. doi:10.1007/BF00696839

Abstract

Our previous publications showed that silicone (polydimethylsiloxane, or PDMS) polymers degrade to monomeric silanols and eventually to C02 in laboratory soil incubations. In this study, 200 cs14C-PDMS was added to soil microcosms (Tuscola sandy loam and Fargo silty clay) in anaerobically digested sludge. Soybeans followed by wheat were grown for 7 months during which microcosms were subjected to 3 leaching events. Recoveries of14C in the microcosms ranged from 47 to 90%. The recovered14C was almost completely in the soils, with trace amounts in leachate and ≤ 2% of the total in plant shoots. Extraction of soils coupled with HPLC-GPC showed that the majority of soill4C was still polymeric, but with lower molecular weight than the original PDMS. From 1 to 5% of the remaining14C was probably small silanols. Results thus confirm laboratory studies and show that PDMS degradation occurs under conditions similar to the field.

Copyright information

© Kluwer Academic Publishers 1996

Authors and Affiliations

  • R. G. Lehmann
    • 1
  • C. L. Frye
    • 1
  • D. A. Tolle
    • 2
  • T. C. Zwick
    • 2
  1. 1.Health and Environmental SciencesDow Corning CorporationMidlandUSA
  2. 2.ColumbusUSA