Sorption of 1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane (DDT) by clays and organoclays.

This study focused on the sorption isotherms of 1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane (p,p'-DDT) and 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (p,p'-DDE) on different original clays (i.e., zeolite, montmorillonite and attapulgite) and organoclay complexes.

Persistence and dissipation of synthetic pyrethroid pesticides in red soils from the Yangtze River Delta area.

Laboratory incubation trials were conducted to investigate the effects of several factors on the persistence as well as the dissipation of three synthetic pyrethroid pesticides in red soils obtained from the Yangtze River Delta region in China. The pyrethroids selected for investigation were cypermethrin, fenvalerate, and deltamethrin, which continue to be used extensively to control pests on farmland in the region despite the concern that they are highly toxic to certain vertebrate and mammalian species. Data from this exploratory study showed that the dissipation half-lives (T (1/2)) tended to correlate with soil pH and soil organic matter contents, but not with soil cation-exchange capacity.