Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/14/2002
Publication Date: 11/14/2002
Citation: CHAPPELL, M.A., EVANGELOU, V.P., LAIRD, D.A., THOMPSON, M.L. IMPACT OF CATION SATURATION AND NONIONIC SURFACTANT BRIJ 35 ON ATRAZINE SORPTION BY PANTHER CREEK SMECTITE. AGRONOMY ABSTRACTS. 2002. CD-ROM. MADISON, WI.
Technical Abstract: We hypothesize that crystalline swelling behavior of the low-charge 2:1 clay Panther Creek (PC) bentonite may be modified (by saturating cation, sample handling, and presence of nonionic surfactant) to alter the clay's affinity for atrazine (ATR). We present preliminary evidence demonstrating that the ATR distribution coefficient (Kd) was cation-saturation dependent (K>Ca>NH4). Moreover, air-drying K-saturated PC before adding ATR increased the ATR Kd to a value approximately seven times greater than that of non-dried samples. In addition, ATR sorption decreased in the presence of increasing concentrations of the nonionic surfactant Brij 35 in a nondegraded form (ATR Kd for 50 mg Brij 35/L>200 mg Brij 35/L>2000 mg Brij 35/L). No clear trend was observed for ATR sorption in the presence of oxygen-degraded Brij 35. On the basis of preliminary TLC and FTIR data, we hypothesize that the surfactant's functional group composition, as well as clay-induced shifts in the chain-size distribution of the Brij 35 polymer, contributed to these differences in ATR sorption.