The Black Sea is the classic marine anoxic basin. It has an oxygenated surface layer overlying a sulfide containing (anoxic) deep layer. This condition has evolved because of the strong density stratification on the water column. The density stratification is strong because water with high salinity enters from the Bosporus Strait and mixes with overlying cold intermediate layer (CIL) water that forms in the winter on the northwest shelf and in the western gyre. The rate of CIL formation is variable in response to changing climate. This mixture of Bosporus outflow and CIL forms the Bosporus Plume which ventilates the deep layers of the Black Sea. New data about the biogeochemical distributions (oxygen, sulfide, nitrate and ammonium) were obtained during R/V Knorr research cruises in 2001 and 2003. The distributions in the upper layers reflect a classic example of the connection between climate forcing, physical regime, chemical fluxes and biological response.

A controlled field study was performed to evaluate the effectiveness of transgenic poplars for phytoremediation. Three hydraulically contained test beds were planted with 12 transgenic poplars, 12 wild type (WT) poplars, or left unplanted, and dosed with equivalent concentrations of trichloroethylene (TCE). Removal of TCE was enhanced in the transgenic tree bed, but not to the extent of the enhanced removal observed in laboratory studies. Total chlorinated ethene removal was 87% in the CYP2E1 bed, 85% in the WT bed, and 34% in the unplanted bed in 2012. Evapotranspiration of TCE from transgenic leaves was reduced by 80% and diffusion of TCE from transgenic stems was reduced by 90% compared to WT. Cis-dichloroethene and vinyl chloride levels were reduced in the transgenic tree bed. Chloride ion accumulated in the planted beds corresponding to the TCE loss, suggesting that contaminant dehalogenation was the primary loss fate.

This article summarizes tracer studies performed at 32 water treatment plants in Washington State ranging from 5 to 5,400 gpm, with contact basins from 200 gal to 1.5 mil gal. Multiple tracer studies were performed at each plant. The goal of the tracer studies was to determine the baffling efficiency (BE) of each basin by determining T10/T, where T10 is the time at which 10% of a tracer is measured at the outlet of a basin, and T is the hydraulic residence time. The tracer studies indicated that most facilities historically used BE values higher than what the tracer studies indicated for calculating compliance with disinfection regulations. The majority of the basins were rectangular, baffled basins. The tracer studies indicated that standard design parameters, such as length‐to‐width ratio, were not as accurate in predicting basin performance compared with calculating baffled channel cross‐sectional velocity. This effect was pronounced where cross‐sectional flow velocity was below the Reynolds laminar flow threshold. For circular, baffled basins, a relationship between cross‐sectional velocity and BE was also evident. The study also identified issues with plants having parallel, chlorine contact basins where uneven flow splitting between basins created an overall system BE less than the BE of individual basins.

This paper defines major advantages for using centrifugal compressors as fuel gas boosters for gas turbines. The first aspect of this paper defines the technical differences between centrifugal compressors and reciprocating compressors as the fuel gas booster. The second aspect of this paper defines the uniqueness and technical advantages of state-of-the-art centrifugal compressors, which are applied for this service.