Specific Adsorption of Nitroaromatic Explosives and Pesticides to Clay Minerals

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