Application of Synchrotron Radiation Techniques to Chemical Issues in the Environmental Sciences

First Investigation on the L Edges of the 249Cf Aquo Ion by X-ray Absorption Spectroscopy

“…This result shows that no formation of an inner-sphere chloro complex occurs for this Cl - concentration (1 M). This is consistent with previous data obtained at the same Cl - concentration for the Pu 3+ aquo ion for the Pu 3+ , Am 3+ , and Cm 3+ aquo ions (respectively 2.51, 2.48, and 2.45 Å) in chloride acidic solution.…”

X‐Ray Absorption Spectroscopy Study of the Local Structure of Heavy Metal Ions Incorporated into Electrodeposited Nickel Oxide Films

“…Local structure of strontium in nickel oxide films.-Strontium is another nuclide of great interest from the standpoint of environmental remediation. 27,28 Strontium was codeposited cathodically with Ni(OH) 2 film from a solution of 0.1 M Ni(NO 3 ) 2 ϩ 0.005 to 0.1 M strontium acetate at a current density of 8 mA/cm 2 for about 15 min. Figure 10 shows the (k) function for Sr ϩ2 incorporated in a Ni(OH) 2 film prepared from 0.1 M Sr acetate.…”

Applications of Synchrotron-Based X-ray Microprobes

“…In contrast, synchrotron-based techniques have emerged as powerful tools for determining the chemical speciation of a wide variety of toxic elements in moist soil samples, waste forms, and biological specimens with little or no chemical pretreatment at detection limits that, on the average, exceed those of conventional methods by several orders of magnitude. The use of conventional XAFS techniques applied to the environmental sciences first appeared in the literature in the late 1980s, and since that time there has been an explosion in the application of XAFS to environmental problems. ,, XAFS spectroscopic investigations have provided unprecedented molecular-level information on reactive mineral phases in soils and sediments and have provided the framework for understanding a number of critical surface-controlled reactions in the environment. Additionally, critical mineral surface reactions involving adsorption- and surface-facilitated polynuclear/nucleation and oxidation−reduction phenomena of a range of contaminants have been investigated by XAFS, and these have been reviewed in detail. ,, While these bulk XAFS studies have and are continuing to produce important molecular-level information on a wide range of mineral sorbents and environmentally relevant sorbates, they have been primarily conducted on homogeneous model monomineralic systems.…”

“…The use of conventional XAFS techniques applied to the environmental sciences first appeared in the literature in the late 1980s, and since that time there has been an explosion in the application of XAFS to environmental problems. ,, XAFS spectroscopic investigations have provided unprecedented molecular-level information on reactive mineral phases in soils and sediments and have provided the framework for understanding a number of critical surface-controlled reactions in the environment. Additionally, critical mineral surface reactions involving adsorption- and surface-facilitated polynuclear/nucleation and oxidation−reduction phenomena of a range of contaminants have been investigated by XAFS, and these have been reviewed in detail. ,, While these bulk XAFS studies have and are continuing to produce important molecular-level information on a wide range of mineral sorbents and environmentally relevant sorbates, they have been primarily conducted on homogeneous model monomineralic systems. Recent developments and deployment of synchrotron-based microanalytical techniques over the past decade, especially in the past five years, are allowing earth and environmental scientists, working on a range of environmental problems, to provide fundamental molecular-level information on contaminants in natural samples.…”