Showing papers by "Stefan B. Haderlein published in 1996"
TL;DR: In this article, it was demonstrated that NACs may adsorb specifically and reversibly to natural clay minerals in aqueous suspension, and specific adsorption coefficients for polynitroaromatic compounds including some important contaminants such as explosives and dinitrophenol herbicides.
Abstract: It is demonstrated that nitroaromatic compounds (NACs) may adsorb specifically and reversibly to natural clay minerals in aqueous suspension. Adsorption of NACs to clays is high when the exchangeable cations at the clays include K+ or NH4+ but is negligibly small for homoionic Na+-, Ca2+-, Mg2+-, and Al3+-clays. Highest adsorption coefficients (Kd values up to 60 000 L kg-1) are found for polynitroaromatic compounds including some important contaminants such as explosives (e.g., trinitrotoluene, trinitrobenzene, dinitrotoluidines) and dinitrophenol herbicides (e.g., DNOC, DINOSEB). Nonaromatic nitro compounds (e.g., RDX) generally exhibit very low Kd values. The specific adsorption of NACs can be rationalized by electron donor−acceptor (EDA) complex formation with oxygens present at the external siloxane surface(s) of clay minerals. Kd values of a given NAC and clay mineral can be estimated from known Kd values of other NACs, even when measured at other clay minerals. The affinity and the adsorption capac...
421 citations