Research Watch

Air Quality Haze in Southeast Asia. Although numerous studies of forest fire plumes have been conducted in other parts of the world, this is the first to be carried out in Southeast Asia with the aim of identifying and quantifying chemical components in the haze, including known or sus­pected carcinogens, mutagens, and teratogens. (Muraleedharan, T. R., et al. "Chemical Characterization of the Haze in Brunei Darussalam During the 1998 Episode", Atmos. Environ. 2000 34 (17), 2725-2731)

Biogeochemistry Methane air-sea exchange. The au­thors report that the flux to the at­mosphere appears to be the main sink for methane in the upper ocean and that microbial oxidation and downward eddy diffusion account for only 3% and 6%, respectively, of the total methane loss from the up­per 300 m. (Holmes, M. E., et al. "Methane Production, Consumption, and Air-Sea Exchange in die Open Ocean: An Evaluation Based on Carbon Isotopic Ratios", Global Bio-geochem. Cycles 2000 14 ((1 ,110)

Climate Atmospheric oxygen. The authors develop a dynamic feedback model of the coupled P, N, C, and 0 2 cycles and use perturbation analysis and a case study of the past 40 million years to test various feedback mech­anisms that have been proposed to stabilize atmospheric oxygen. (Len-ton, T. M.; Watson, J. "Redfield Revis­ited. 2. What Regulates the Oxygen Content of the Atmosphere?" Global Biogeochem. Cycles s000,14 41), 249-268)

Heat and moisture. The authors in­vestigate changing shapes and inten­sities of warm and cool pockets and the development of cliffs and pla­teaus at minimum temperatures and compare their findings with similar aspects for Pune City documented in earlier studies. (Deosthali, V "Impact of Rapid Urban Growth on Heat and Moisture Islands in Pune City, India", Atmos. Environ. 2000 34 (17) 2745-2754)

Tropospheric ozone. The authors of this review state that the large-scale increase in tropospheric 0 3 levels is one of the most crucial environmen­tal problems to solve during the coming decades because of its sig­nificant consequences for human health and nature. (Guicherit, R.; Roemer, M. "Tropospheric Ozone Trends", Chemosphere: Global Change Sci. 2000, 2 (2), 167-183)

Chemistry Multimicrobial sensor. Two micro­bial strains with different substrate spectra were immobilized separately within a single biosensor chip fea­turing four individually addressable platinum electrodes; these were sputtered onto the inner surface of

four isolated pyramidal "contain­ments" micromachined on a silicon wafer. (Koenig, A., et al. "Multimicro­bial Sensor Using Microstructured Three-Dimensional Electrodes Based on Silicon Technology", Anal. Chem. 2000, 72 (9), 2022-2028)

Drinking Water

Germany's water. Topics discussed in this review of the drinking water supply situation in Germany include investment and water prices; water consumption changes; water loss in households; endocrine-effective sub­stances in drinking water; N03" in drinking water; and pesticides in drinking water. (Lohse, M.; Dziopak, J. "Aspects of Drinking Water Supply in Germany", Environ. Prot. Eng. 1999,25(4), 11-19)

Minimizing DBPs. The concept of the Minimum C102 Dosage (MCDD) is developed to give a clue to the water companies for an optimized C102 dose without compromising the disinfection efficiency. (Schmidt, W, et al. "Minimization of Disinfec­tion By-Products Formation in Water Purification Process Using Chlorine Dioxide—Case Studies", Ozone: Scii Eng. 2000, 22 (2), 215-226)

Cleaner paper pulp production Manufacturing of bleached pulp for manufacturing paper products is trending to­ward use of totally chlorine-free (TCF) bleaching and zero-liquid effluent (ZLE) pro­cesses. However, for more widespread deployment of these techniques, there are still several obstacles to overcome. One major challenge in closed-cycle TCF mills is the problem of having to handle lipophilic wood extractives that can accumulate in the circuits. The compounds form the pitch deposits that can lead to low-quality final products and economic losses in mill operations. A. Gutierrez and co-workers evalu­ated the use of the extractive-degrading fungi Bjerkandera adusta, Phlebia radiata, Pleurotus pulmonarrus, ,nd Poria aubvermispora for removing ththe compounun from Eucalyptus globulus wood using solid-state fermentation conditions. Reeults indicate that levels of problematic compounds can be reduced by up to 75% using fungal pretreatment. Moreover, the potential acute toxicity of black liquors, a waste stream, was significantly reduced. {Environ. Sci. Techno!., this issue, pp. 3735-3709)

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