Record Display for the EPA National Library Catalog


Main Title Monodisperse Ferrous Phosphate Colloids in an Anoxic Groundwater Plume.
Author Gschwend, P. M. ; Reynolds, M. D. ;
CORP Author Massachusetts Inst. of Tech., Cambridge. Dept. of Civil Engineering.;Robert S. Kerr Environmental Research Lab., Ada, OK.
Year Published 1987
Report Number EPA-R-812466; EPA/600/J-87/056;
Stock Number PB87-213310
Additional Subjects Fluid infiltration ; Ground water ; Wells ; Sewage disposal ; Sorbents ; Contaminants ; Sorption ; Surface chemistry ; Reprints ; Ferrous phosphate ; Cape Cod(Massachusetts)
Library Call Number Additional Info Location Last
NTIS  PB87-213310 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 21p
Groundwater samples collected near a secondary-sewage infiltration site on Cape Cod, Massachusetts, were examined for colloidal materials (10-1000 nm). In two wells the water contained a population of monodisperse 100-nm particles, detected using laser-light scattering and autocorrelation data processing. SEM and SEM-EDAX analysis of these colloidal materials collected on ultrafilters confirmed the laser light scattering result and revealed that these microparticles consisted of primarily iron and phosphorus in a 1.86 Fe to 1.0 P stoichiometric ratio. Chemcial analyses of the water samples, together with equilibrium solubility calculations, strongly suggest that the ion-activity product should exceed the solubility product of a 100-nm diameter predominantly vivianite-type colloidal phase. In light of the results, researchers conclude that these microparticles were formed by sewage-derived phosphate combining with ferrous iron released from the aquifer solids, and that these colloids may be moving in the groundwater flow. Such a subsurface transport process could have major implications regarding the movement of particle-reactive pollutants traditionally viewed as non-mobile in groundwater. (Copyright (c) 1987 Elsevier Science Publishers B.V.)