The
National Research Council is accepting applications for
Postdoctoral Research Awards at the
US Environmental Protection Agency's National Risk Management Research Laboratory Cincinnati, OH The National Research Council (NRC) will offer two competitive Associateship awards for research in the Land Remediation and Pollution Control Division of the US EPA'S National Risk Management Research Laboratory in Cincinnati, OH. Opportunities are available to Ph.D. scientists and engineers with background and interest in acid mine drainage treatment technology & bioprocessing of metals. The awardees will work in the above project area as guest investigators in residence at the US EPA NRMRL. The annual stipend for recent Ph.D. recipients ranges from $35,000 to $43,000 and is appropriately higher for more experienced researchers. Each award is for one year, renewable for a total tenure of three years. Support is provided for relocation and professional travel, and a health insurance program is offered.
For further information contact: Dr. Henry H. Tabak US EPA NRMRL 26 West Martin Luther King, Jr. Drive, Cincinnati OH 45268 tel: (513)569-7861 fax: (513)569-7105 email:
[email protected] Applications, submitted directly to the NRC, are accepted on a continuous basis throughout the year. Those postmarked by August 15 will be reviewed in the October competition and by January 15, 1998 in the February competition. For application materials contact: NATIONAL RESEARCH COUNCIL
Associateship Programs (TJ2114/EC4) 2101 Constitution Avenue NW Washington, DC 20418 fax: (202) 334-2759 email:
[email protected] CIRCLE 4 ON READER SERVICE CARD
On-line nitrification monitoring sensor Monitoring of nitrogen levels in wastewater treatment processes is required by environmental legislation. The biological nitrogen removal processes require careful monitoring and control. Krist Gernaey and colleagues evaluated a recently developed on-line titrimetric sensor that estimates the ammonium nitrogen concentration. The titration procedure involves monitoring the amount and rate of base addition required to achieve and maintain a predetermined pH value (8 2) in a sludge sample Analysis time was approximately 1 lh data were lyzed by detection of slope changes in the titration curve The procedure is inexpensive requires no sample preparation and provides information on the sludoe nitrification rate (Environ.ci Technol this issis 2350-551
pesticides. (Anal. Chem. 1997, 69, 1426-35)
Pesticides in water Determination of pesticide residues in water typically requires separate extraction and analysis procedures for neutral and acidic pesticides. T. D. Bucheli and colleagues report a new procedure for simultaneous identification and quantification of these pesticides at ng/L concentrations. Pesticides are extracted from a 1-L water sample by a graphitized carbon black, solid-phase extraction cartridge and then sequentially eluted. Neutral pesticides are eluted with methylene chloride/methanol cinci cicidic pesticides cire eluted with methylene chloride/ethyl acetate and trifluoroacetic acid Diazomethane was added to the acidic fraction after extraction to derivatize the acids before CC/MS analysis Three classes of Desticides triazines amides and phenoxy acids, were tested for recovery and method deterHon
limits (Anal
1997
Testing EPA methods EPA has proposed new methods for determining bioconcentrated contaminants in surface waters that are not covered by water quality criteria. Among the methods are extensive
3 4 6 A • VOL. 31, NO. 8, 1997 / ENVIRONMENTAL SCIENCE & TECHNOLOGY / NEWS
sample cleanup followed by GC/MS and mass spectral library searches to identify unknowns. D.C.L. Wong and colleagues report results of a multilaboratory test of the methods. Because method and laboratory variances were large, interlaboratory comparisons were poor. Recoveries were below 50% for many compounds and matrices, and most labs identified fewer than half of the eight spiked compounds. The library search method was unable to detect some reference spike chemicals. Laboratories found the multistep procedures complex time-intensive and analyte loss [Environ Toxicol Chem 1997 16 617-24)
SOIL Predicting toxicity Knowledge about interactions between soils and pesticides is important because large amounts of pesticides in soil may be sorbed to organic matter and are not bioavailable. R. Ronday and co-workers examined three soil-pesticide parameters in loam, sand, and peat soils to determine which parameter is the best predictor of toxicity. These parameters were total pesticide content (mass pesticide per dry weight soil), organic matter normalized content (mass pesticide per mass soil organic matter) and pore water concentration (pesticide concentration in the pore water) Pore water concentration Wcis the most reliable nredictor of toxicity to trie snil oreanism Fohomia Candida rpeardless of soil tvnp ond chptnical soil con-
tact time The authors noted that m e t h o d s nverestimatp actnal nnrp water rnnrpntratin (Fnv'ron Tnrirnl Chpm 1997 7fi fini-7)
Contributors: Michael Brauer, University of British Columbia, Vancouver; Brian Eitzer, Connecticut Agricultural Experiment Station, New Haven; Stephen Geiger, Remediation Technologies, Inc., King of Prussia, Pa.; Vincent Hand, Miami University, Institute of Environmental Sciences, Oxford, Ohio; Louis Kovach, Ecolife Associates, Wilmington, Del.; Geoffrey Nobes, McGill University, Montreal; Raewyn Town, Queen's University of Belfast, Northern Ireland; and Margaret Whittake,, NSF Internationa,, Ann Arbor, Mich.
