The partitioning and modelling of pesticide parathion in a surfactant-assisted soil-washing system

Wei Chu, K. H. Chan, W. K. Choy

Research output: Journal article publicationJournal articleAcademic researchpeer-review

19 Citations (Scopus)


Soil sorption of organic pollutants has long been a problematic in the soil washing process because of its durability and low water solubility. This paper discussed the soil washing phenomena over a wide range of parathion concentrations and several soil samples at various fractions of organic content (foc) levels. When parathion dosage is set below the water solubility, washing performance is stable for surfactant concentrations above critical micelle concentration (cmc) and it is observed that more than 90% of parathion can be washed out when dosage is five times lower than the solubility limit. However, such trends change when non-aqueous phase liquids (NAPL) is present in the system. Parathion extraction depends very much on the surfactant dosage but is not affected by the levels of focin the system. In between the extreme parathion dosage, a two-stage pattern is observed in these boundary regions. Washing performance is first increased with additional surfactant, but the increase slows down gradually since the sorption sites are believed to be saturated by the huge amount of surfactant in the system. A mathematical model has included focto demonstrate such behavior and this can be used as a prediction for extraction.
Original languageEnglish
Pages (from-to)711-716
Number of pages6
Issue number5
Publication statusPublished - 1 Jul 2006


  • Brij 35
  • Model
  • NAPL
  • Parathion
  • Sorption

ASJC Scopus subject areas

  • Environmental Chemistry
  • Environmental Science(all)

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