Modeling Neural networks. Commonly mea­sured fecal bacteria concentrations in water and rainfall data were used as inputs for training a neural net­work model to distinguish between urban and agricultural fecal contam­ination present in inputs to a drink­ing water reservoir. (Brion, G. M.; Lingireddy, S. "A Neural Network to Identifying Nonpoint Sources of Microbial Contamination", Water Res. 1999, 33 (14), 3099-3106)

Nitrogen concentrations. An artifi­cial neural network was developed, validated, and tested using 927 non-point source watersheds studied for relations between macrodrainage area characteristics and nutrient lev­els in streams. (Lek, S., et al. "Pre­dicting Stream Nitrogen Concentra­tion From Watershed Features Using Neural Networks", Water Res. 1999, 33 (16), 3469-3478)

Treatment

Chloromethane degradation. The authors examined the potential for using laboratory-synthesized nanoscale iron particles to transform chloromethanes and achieved rapid transformations of tetrachlorometh-ane and trichloromethane with pal-ladized nanoscale iron particles. (Lien, H.-L.; Zhang, W.-X. "Transfor­mation of Chlorinated Methanes by Nanoscale Iron Particles", /. Environ. Eng. 1999, 125 (11), 1042-1047)

Chromate remediation. A small-scale field test was initiated at an old chrome-plating facility to evaluate in situ remediation of groundwater con­taminated with chromate using a per­meable reactive barrier composed of a mixture of zero-valent Fe, sand, and aquifer sediment. (Puis, R. W.; Paul, C. J.; Powell, R. M. "The Application of In Situ Permeable Reactive (Zero-Valent Iron) Barrier Technology for the Re­mediation of Chromate-Contaminated Groundwater: A Field Test" Appl. Geo-chem. 1999 14 (8) 989-1000)

Mineral and mine drainage. This review of minerals and mine drain­age includes 106 references and de­scribes analytical methods, site as­

sessment, tailings disposal/mine spoil, acid-mine drainage, lotic sys­tems, site rehabilitation, removal technologies, and biological treat­ment. (Smith, D. P.; Kalch, R. "Miner­als and Mine Drainage", Water Envi­ron. Res. 1999, 71 (5), 822-828)

Controlling mercury emissions Optimal mercury control technologies are needed for coal-fired power plants, municipal waste combustors, and hospital incinerators, which ac­count for more than 70% of anthropo­genic mercury emissions. W. Liu and co-workers performed laboratory ex­periments to investigate the optimiza­tion of high-temperature sulfur im­pregnation on activated carbon for permanent sequestration of elemental mercury vapors. The fate of spent adsorbents was assessed using a toxicity characteristics leaching pro­cedure (TCLP) Although mercury con­centration in all leachates was below the TCLP limit (0 2 mg/L) virgin acti­vated carbon lost a significant fraction of the adsorbed elemental mercury during storage while no loss was observed for sulfur-impregnated car-

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Soil TNT-contaminated soil. The fate of 2,4,6-trinitrotoluene (TNT) and its reduction products was analyzed using a TNT-contaminated soil spiked with [14C]TNT. (Achtnich, C , et al. "Irreversible Binding of Biologi­cally Reduced 2,4,6-trinitrotoluene to Soil", Environ. Toxicol. Chem. 1999, 18 (11), 2416-2423)

Waste Food processing wastes. This review, which contains 58 references on food processing wastes, discusses such top­ics as dairy; sugar and confectionery; meat, poultry, and seafood; grains;

beverages; fruit and vegetables; and solid wastes. (Ross, C. C, et al. "Food Processing Wastes", Water Environ. Res. 1999, 71 (5), 812-816)

Mercury removal. The origins and fate of mercury found in hydrocar­bon waste are discussed from the perspective of waste minimization, treatment, and disposal (Wilhelm, S. M. "Generation and Disposal of Petroleum Processing Waste That Contains Mercury", Environ. Prog. 1999, 18 (2), 130-143)

Wastewater Disinfection and antimicrobial pro­cesses. Ninety-five references are in­cluded in this review of disinfection and antimicrobial processes in waste­water treatment, which addresses reg­ulations and policies, health risk, dis­infection methods, microbiological and disinfection chemicals, analytical methods, and distribution system re-growth and biofilm. (Kuo, J.-E; Ya-mashita, L. "Disinfection and Antimi­crobial Processes" Water Environ. Res. 1999 71 (5), 685-692)

Water Pathogens in water. This review pre­sents 227 references concerning the detection and occurrence of indicator organisms and pathogens in water and wastewater and discusses such topics as microorganism detection, indicator organisms, bacterial patho­gens and emerging pathogens, viruses, protozoa, and helminths and other parasites. (Baker, K. H.; Herson, D. S. "Detection and Occurrence of Indica­tor Organisms and Pathogens" Water Environ. Res. 1999 71 (5) 530-551)

Stormwater sampling. The results of this study strongly suggest that dis­crete sampling of stormwater outfalls is insufficient to characterize the con­centrations and distributions of per­sistent hydrophobic contaminants. (Wenning, R. J., et al. "Polychlorinated Dibenzo-p-Dioxins and Dibenzo-furans in Stormwater Outfalls Adja­cent to Urban Areas and Petroleum Refineries in San Francisco Bay, Cali­fornia" Arch. Environ. Contam. Toxicol. 1999 37 (3) 290-302)

9 2 A • FEBRUARY 1, 2000 / ENVIRONMENTAL SCIENCE & TECHNOLOGY / NEWS