SORPTION AND AEROBIC BIODEGRADATION OF STRYCHNINE ALKALOID IN VARIOUSSOIL SYSTEMS

Strychnine alkaloid was demonstrated to sorb strongly to several weste rn soils that varied in organic matter and ranged in texture from a lo amy sand to a sandy clay,loam. Freundlich sorption coefficients (K) fo r the test soils varied from 40 to 169. A direct relationship was obse rved between strychnine sorption and cation exchange capacity but not between sorption and organic matter content. Strychnine sorption was o nly partially reversible (12-44%). Degradation of 10 mu g/g strychnine in sandy loam and sandy clay loam soils occurred in three distinct ph ases, which included a lag phase, a rapid loss phase, and a leveling o ff or soil binding phase. Approximately 50% of the strychnine was lost from the two soils within 24-27 days, with the appearance of a degrad ation product occurring early in the study. The initial breakdown prod ucts of strychnine are believed to be polar compounds with strong sorp tion characteristics.