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The capacity of UV-catalyzed Fenton oxidation to destroy mono-, di- and trinitrotoluenes (MNT, DNT, TNT) in aqueous solution was evaluated. Mononitrotoluenes were rapidly destroyed by Fenton oxidation in the dark at pH 3.0 or by UV/Fenton oxidation without pH adjustment. UV/Fenton oxidation at pH 3.0 was most effective for DNT and TNT destruction. The number and position of nitro substitutions influenced oxidation rate: 2-nitrotoluene > 4-nitrotoluene > 2,4-dinitrotoluene > 2,6-dinitrotoluene > 2,4,6-trinitrotoluene. UV/Fenton oxidation mineralized more than 95% of the TNT in aqueous extracts of contaminated soil. While dissolved humic and fulvic acids differentially influenced destruction rate, total TNT destroyed after 4 h was not greatly affected. Our results demonstrated that UV-catalyzed Fenton oxidation effectively destroyed nitrotoluenes in water and aqueous extracts of contaminated soil.

Past disposal practices at munitions production facilities have generated numerous hectares of TNT-contaminated soil. We previously showed that Fenton oxidation could destroy TNT in soil and water. Our objective was to determine the potential of combining Fenton oxidation with soil washing to remediate TNT-contaminated soil and to test whether plants could be established on washed soil. Aqueous soil washing effectively reduced CH3CN-extractable TNT concentrations but large volumes of water were required to meet remediation goals. This volume was reduced when the wash water temperature was increased to 45°C. Complete destruction of TNT in wash solutions was achieved by Fenton oxidation with greater than 40% mineralized. Combining soil washing with phytoremediation will require plant establishment on the washed soil. We observed no significant reduction in tall fescue (Festuca arundinacea Schreb.) germination or early seedling development in contaminated soil following two wash cycles (soil:H2O, 1:5). This corresponded to reducing CH3CN-extractable soil concentrations from 499 mg TNT kg−1 to approximately 72 mg TNT kg−1. Our results indicate Fenton oxidation can be combined with soil washing for effective abiotic remediation of TNT-contaminated soils. Washed soils may be planted to tall fescue, demonstrating the potential of combining soil washing, Fenton oxidation and phytoremediation into an integrated treatment train for TNT-contaminated sites.

Numerous approximations of the Fermi-Dirac integral F j (x) appear in the literature for j = 1 2 . We compare some of these approximations and suggest which ones should be used to optimise both accuracy and speed of computation in an application of device modeling.

The effects of thickness and substrate of d.c. magnetron sputtered CoCr films are investigated by spectroellipsometry. The ellipsometric data indicate that the morphology of CoCr films varies as a function of the film thickness and proper choice of substrate can reduce the thickness dependence. It is shown that an NiCr underlayer is capable of reducing the thickness dependence because of its similarity in microstructure to CoCr.

The magnetic properties of d.c. magnetron sputtered CoCr (20 at.% Cr) thin films have been studied as a function of the substrate temperature during film growth. A change in film morphology is observed at about 200°C. This change is accompanied by an abrupt change in coercivity, remanence and anisotropy. The effects of substrate type on the magnetic properties have been investigated. The Hall resistivity is measured as a function of temperature.