Dissipation of chlorpyrifos from tap, river and brackish waters in glass aquaria.

Persistence of Dursban 2E formulation of chlorpyrifos was studied in aerated and unaerated tap, river and brackish water, under laboratory conditions. Adsorption of residues onto a glass surface over 12-24 h was 12%. The half-lives of the residues in aerated and unaerated (data in parenthesis) tap, river and brackish waters were 23 and (403) h, 3.2 and (60) h, and 5.8 and 232 h, respectively. The kinetics of dissipation of residues from aerated and unaerated tap, river and brackish waters suggested a linear relationship for most of the data sets, and could not be ascribed to distinct first- or second-order models.