DILUTION AND DECAY OF AQUATIC HERBICIDES IN FLOWING CHANNELS

The behaviour of herbicides injected into flowing irrigation channels for aquatic weed control is analysed. Solutions to the one-dimensional convective-diffusion equation are given for instantaneous and step-function injections of a decaying tracer. The basic solutions are used to derive methods for determining the degradation rate from field experiments, and the total exposure to the herbicide as the water flows over the weeds. It is shown that some significant aspects of herbicide behaviour are unaffected by dispersion, and depend only on the degradation rate constant and the travel time of the material. Observations from trials in irrigation channels in the U.S.A. and Australia with the herbicide acrolein are analysed. The herbicide application rates and computed exposures vary greatly. Degradation rate constants are more nearly equal. /Author/

• Corporate Authors:

  North-Holland Publishing Company

  P.O. Box 211
  1000 AE Amsterdam,   Netherlands 
• Authors:
  • O'Loughlin, E M
  • Bowmer, K H
• Publication Date: 1975-8

Media Info

• Features: Appendices; Figures; References; Tables;
• Pagination: p. 217-236
• Serial:
  • Journal of Hydrology
  • Volume: 26
  • Issue Number: 3/4

Subject/Index Terms

• TRT Terms: Aquatic life; Control; Crash exposure; Dilution; Equations; Field tests; Herbicides; Irrigation; Optical diffusion; Rates; Stream channels; Weeds
• Uncontrolled Terms: Aquatic pests; Degradation; Exposure
• Old TRIS Terms: Dispersion; Irrigation water
• Subject Areas: Highways; Hydraulics and Hydrology; Safety and Human Factors;

Filing Info

• Accession Number: 00125015
• Record Type: Publication
• Files: TRIS
• Created Date: Oct 18 1975 12:00AM