From 1974 to 1984, 543 Mg ha(-1) of biosolids were applied to portions of a land-reclamation site in Fulton County, IL. Soil organic C increased to 5.1% then decreased significantly (p < 0.01) to 3.8% following cessation of biosolids applications (1985-1997). Metal concentrations in amended soils (1995-1997) were not significantly different (p > 0.05) (Ni and Zn) or were significantly lower (p < 0.05) (6.4% for Cd and 8.4% for Cu) than concentrations from 1985-1987. For the same biosolids-amended fields, metal concentrations in corn (Zea mays L.) either remained the same (p > 0.05, grain Cu and Zn) or decreased (p < 0.05, grain Cd and Ni, leaf Cd, Cu, Ni, Zn) for plants grown in 1995-1997 compared with plants grown immediately following termination of biosolids applications (1985-1987). Biosolids application increased (p < 0.05) Cd and Zn concentrations in grain compared with unamended fields (0.01 to 0.10 mg kg(-1) for Cd and 23 to 28 mg kg(-1) for Zn) but had no effect (p > 0.05) on grain Ni concentrations. Biosolids reduced (p < 0.05) Cu concentration in grain compared with grain from unamended fields (1.9 to 1.5 mg kg(-1)). Biosolids increased (p < 0.05) Cd, Ni, and Zn concentrations in leaves compared with unamended fields (0.3 to 5.6 mg kg(-1) for Cd, 0.2 to 0.5 mg kg(-1) for Ni, and 32 to 87 mg kg(-1) for Zn), but had no significant effect (p > 0.05) on leaf Cu concentrations. Based on results from this field study, USEPA's Part 503 risk model overpredicted transfer of these metals from biosolids-amended soil to corn.

Encouraged by a finding that the pathogen analyses of numerous samples of the final product of the Metropolitan Water Reclamation District of Greater Chicago, Illinois (District), met the U.S. Environmental Protection Agency (U.S. EPA) Class A criteria, the District optimized and codified the operation of its sludge processing trains (SPTs), submitted a petition to the U.S. EPA Pathogen Equivalency Committee for obtaining certification of its SPTs as equivalent to a process to further reduce pathogens, and conducted a 3year full-scale study. The objective of the study was to determine whether or not the District's SPTs consistently produced a Class A biosolids final product. The primary conclusion drawn from this optimized and codified operation study was that all batches of the final air-dried product complied with the Class A criteria as specified by U.S. EPA in the Part 503 regulations. Water Environ. Res., 72, 413 (2000).

Total cyanide analysis by distillation is used most commonly to assess cyanide content of water samples. This manual method is robust but slow and provides no information about cyanide speciation, a significant limitation in that cyanide species have substantially different toxicity characteristics. Seven alternative methods for the analysis of cyanide species or groups of species were evaluated in reagent water and five different contaminated water matrices, including five species-specific methods--weak acid dissociable (WAD) cyanide, free cyanide by microdiffusion, available cyanide, automated WAD cyanide by thin film distillation, metal cyanides by ion chromatography--and two automated techniques for total cyanide--total cyanide bythin film distillation and total cyanide by low-power UV digestion. The species-specific cyanide analytical techniques achieved low, ppb-level detection limits and exhibited satisfactory accuracy and precision for most contaminated waters. Analysis of low concentrations of cyanide species in raw wastewater was problematical for the available cyanide and ion chromatography methods, which experienced significant interference problems and/or low recoveries. There was recovery of significant diffusible cyanide in microdiffusion tests with nickel-cyanide-spiked samples, reflecting dissociation of this weak metal-cyanide complex during the test and demonstrating that the test can recover some fraction of WAD cyanide in addition to free cyanide. The automated total cyanide methods, which involve UV digestion, achieved low detection limits for most waters but exhibited low recoveries for some waters.

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Statistical methods were developed for analyzing the results of a study of pathogen densities for sludge samples taken over the four stages of the solids processing trains (SPTs) operating at the Stickney and Calumet Water Reclamation Plants of the Metropolitan Water Reclamation District of Greater Chicago, Illinois (District). These methods also apply to pathogen density studies for other biosolids processes. Analysis of covariance models were used to estimate expected pathogen densities for individual solids processing stages. Cross-validation was used to select appropriate analysis of covariance models. Nonparametric methods were used to estimate distributions for pathogen density reductions between solids processing stages and to assess the effect of hypothetical surges and expansions in initial stage pathogen densities on final stage pathogen densities. These statistical analyses demonstrate that the District's SPTs achieve target reductions in enteric virus and viable helminth ova densities with high probabilities. Furthermore, the District's SPTs would still meet U.S. Environmental Protection Agency Class A restrictions for these pathogens with high probabilities, even if the initial stage pathogen densities observed in the study undergo extreme hypothetical surges or extreme hypothetical uniform expansions, that is, exceptionally large isolated bursts of pathogens or exceptionally large sustained increases in pathogens in the feed to the SPTs. Water Environ. Res., 72, 423 (2000).