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Self‐Diffusion of P in Kaolinite Treated With Ca or NH4 Salts and With an Organic Dye
Author(s) -
Peaslee D. E.,
Phillips R. E.
Publication year - 1970
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1970.03615995003400020009x
Subject(s) - kaolinite , diffusion , chemistry , sulfate , phosphorus , inorganic chemistry , clay minerals , organic dye , nuclear chemistry , mineralogy , organic chemistry , chemical engineering , physics , engineering , thermodynamics
Self‐diffusion coefficients of P ranged from 2.9 to 16.4 × 10 ‐8 cm 2 sec ‐1 in kaolinite clay that received treatments of salts and differing rates of gallein, an organic dye. The presence of 7.75 me/100 g clay of the NO 3 ‐ , Cl ‐ or SO 4 2‐ salts of Ca or NH 4 significantly decreased the diffusion coefficients of phosphorus from those of the untreated clay. Sulfate decreased the coefficients the least; coefficients in the presence of NO 3 ‐ and Cl ‐ were similar, but significantly less than in the presence of SO 4 2‐ . The self‐diffusion coefficients in the presence of the Ca‐salts were significantly larger than those in the presence of the NH 4 ‐salts. When up to 5.2 m moles of gallein dye per 100 g of clay were added prior to the addition of P, diffusion coefficients increased in a linear manner. The effect of the dye was somewhat less when added after the addition of the P. The increases and decreases in diffusion coefficients induced by the treatments were reflected in changes in water‐soluble P in the treated clay. Phosphorus was added to the kaolinite clay at the rate of 160 ppm for all treatments of salts and dye.