ENVIRONMENTAL SCIENCE & TECHNOLOGY 1998 Vol.32 No.19

1. Aggregation in the Marine Environment∥George A.Jackson.-p2805 　 The role of particie aggregation in the marine environment is reviewed， 　 and comparisons are made between observational data and theoretical　　 　 results 2. On Points of Zero Charge∥Garrison Sposito.-p2815 　 Charge conservation and thermodynamic stability conditions impose　　　 　 constraints that any molecular model　of　the　electrical　double　layer 　 must respect 3. Application of the Surface Complexation Concept to Complex Mineral　　　 　 Assemblages∥J.A.Davis.-p2820 　 Two Types of modeling approaches without electrical double-layer　　　　 　 correction are illustrated for describing inorganic adsorp-tion in　　　 　 aqueous　environments 4. On the Acid-Base Chemistry of Permanently Charged Minerals∥Anne M.L.　 　 Kraepiel.-p2829 　 The effect of a permanent charge on the acid-base chemistry of solids　 　 is included in surface complexation models， which are then applied to　 　 kaolinite and montmorillonite 5. Surface Oxidation of Pyrite as a Function of pH∥Pascale Bonnissel-　　 　 Gissinger.-p2839 　 Oxidation of pyrite is characterized from pH 2.5 to pH 12 by X-ray　　　 　 Photoelectron spectroscopy and aqueous analyses of sul-fur and iron 6. Influence of Structural Features on Sorption of NOM-Analogue Organic　　 　 Acids to Goethite∥Cynthia R.Evanko.-p2846 　 Sorption experiments with an extensive series of organic acids were　　 　 performed to　assess　effects　of　particular　features　of　com- pound 　 structure on sorption to goethite 7. Oxalate Adsorption at a Plagioclase (An↓47) surface and Models for　　 　 Ligand-Promoted Dissolution∥Lisa L.Stillings.-p2856 　 Ligand-enchanced dissolution rate of andesine feldspar in the presence　 　 of 0-8 mM oxalic acid， pH 3-5， is modeled as a　func- tion　of　proton， 　 bioxalate， and oxalate adsorption to the mineral surface 8. Experimental and Theoretical Treatment of Elementary Ligand Exchange　　 　 Reaction in Aluminum Complexes∥Brian L.Phillips.-p2865 　 Computation and experimental rate studies of aluminum cat-ion　complexes 　 are applied to model surface reactions 9. Active Sites and the Non-Steady-State Dissolution of Hematite∥Sherry　 　 D.Samson.-p2871 　 The response of hematite dissolution rate to pH- jumps　is　con- sistent 　 with the depletion and regeneration of a reservoir of dissolution-　　　 　 active Fe surface sites in response to pH cycles 10.Influence of pH and Competitive Adsorption on the Kinetics of Ligand-　 　 Promoted Dissolution of Aluminum Oxide∥Stephan M.Kraemer.-p2876 　 Coadsorbing ligands can have either competing or synergistic effects　on 　 the rates of aluminum oxide dissolution;the type of effect　depends　on 　 ligand structure 11.Humic Substance Formation via the Oxidative Weathering of Coal∥Soobum　 　 Chang.-p2883 　 Aqueous oxidation rates of pyrite-free bituminous coal and consequent　 　 humic substance formation are measured at 24 and 50 ℃ with a dual-cell 　 flow-through method 12.A Generalized Description of Aquatic Colloidal lnteractions: The Three- 　 colloidal Component Approach∥Jacques Buffle.-p2887 　 Aggregate formation in aquatic systems is interpreted by con-sidering　 　 the roles of inorganic colloids，　rigid　biopolymers，　 and　refractory 　 organic macromolecules 13.Adsorption of Weak Polyelectrolytes on Metal Oxide Surfaces: A Hybrid　 　 SC/SF Approach∥Kwok-Keung Au.-p2900 　 A polyelectrolyte adsorption model is combined with a surface　　　　　 　 complexation　model　to　describe　the　adsorption　of　a　weak　poly　 　 -electrolyte on hematite over wide ranges of pH and ionic strength 14.Quantification of Polymer Interaction in Bacterial Adhesion∥Barbara A. 　 Jucker.-p2909