Tuesday, November 6, 2007 - 10:45 AM
188-6

Investigation of Silver Chemicals for Wood Preservation and Soil Biology – An Exploratory Research.

Krishnaswamy Jayachandran1, Seema Sah1, and Jeffrey Ellis2. (1) 11200 SW 8th St., Florida International University, Florida International University, Dep. of Environmental Studies, Miami, FL 33199, (2) Chemicals and Plastics Technology, 4347 Foxtail Lane, Weston, FL 33331

Silver metal and silver compounds have been used dating back to ancient times for their antimicrobial properties. It is employed as a bactericide and algaecide in an ever increasing number of water purification systems in hospitals and, more recently, domestic households. Silver ions have been used to purify drinking water and swimming pool water for generations. Developing the capability to use Silver chemicals for wood preservation in soil and water is important to the goal of preventing environmental contamination by current toxic wood preservatives. Current knowledge of silver chemicals for wood preservation is not sufficient to predict their effectiveness against wood destroying and disfiguring organisms. Overall objective is to determine the effectiveness of silver chemicals as wood preservatives in soil and water. Wooden blocks were weighed to the nearest 0.01g before chemical treatment. The blocks were submerged in the treating media, and then exposed to 30 minutes under vacuum (approximately 300 mm Hg). Treated blocks were exposed at atmospheric pressure for 30 minutes to allow for equilibration to occur. Liquid formulations were used as supplied. Solid formulations were diluted in silicone (Dow Corning Silicone 9011 - 3% by weight). Treated wooden block weights after impregnation were recorded. Treated blocks were placed in soil beds, half exposed to air and the other half buried in soil. A grading system [from 10 to 0] is used to evaluate the degree of discoloration and decay of the wood samples. We have evaluated 14 silver formulations of liquid and solid chemicals from 10 companies and evaluated the effect on soil biology. To our knowledge, we are the first to carry out this exploratory research and report the possibilities for alternative wood preservation by silver formulations.