Grower reported pesticide poisonings among Florida citrus fieldworkers

In a 1981 survey of 436 Florida citrus growers, 27 pesticide related poisoning incidents were reported that were to have taken place within one year of the interview date. From these reports it is possible to estimate that there are 376 citrus fieldworker related poisonings per year in Florida. This number of estimated poisonings may be developed into an incidence rate of 113 fieldworker poisonings per 10,000 fieldworkers.     

The first commercial supercritical water oxidation sludge processing plant

Final disposal of sludge continues to be one of the more pressing problems for the wastewater treatment industry. Present regulations for municipal sludge have favored beneficial use, primarily in land application. However, several agencies and entities have warned of potential health risks associated with these methods. Hydrothermal oxidation provides an alternative method that addresses the health concerns associated with sludge disposal by completely converting all organic matter in the sludge to carbon dioxide, water, and other innocuous materials. A hydrothermal oxidation system using HydroProcessing, L.L.C.'s HydroSolids process has been installed at Harlingen, Texas to process up to 9.8 dry tons per day of sludge. Based on a literature review, this system is the largest hydrothermal oxidation system in the world, and the only one built specifically to process a sludge. Start up of Unit 1 of two units of the HTO system began in April 2001. Early results have indicated COD conversion rates in excess of 99.9%. Harlingen Waterworks System estimates that the HydroSolids system will cost less than other alternatives such as autothermal thermophilic aerobic digestion and more traditional forms of digestion that still require dewatering and final disposal. The Waterworks intends to generate income from the sale of energy in the form of hot water and the use of carbon dioxide from the HydroSolids process for neutralization of high pH industrial effluent. The Waterworks also expects to generate income from the treatment of septage and grease trap wastes.     

Development of a biaxial loading frame for sheet metal

Characterization of the evolving yield loci and forming limit diagrams for sheet materials under biaxial loading is necessary for the development of accurate sheet metal forming process simulations. Biaxial tension testing has been shown to have significant advantages over the current computational and experimental methods for such material characterization; however, the few commercially available loading frames are far too large and expensive to be practical for most metal forming research laboratories. In this paper, the design of a practical servohydraulic biaxial loading frame is presented. The design, control, and operation of the loading frame are discussed in detail, and experimental data is provided to validate the effectiveness of the control system with respect to specimen center shifting.     

Applying the zoo model to conservation of threatened exceptional plant species

Maintaining a living plant collection is the most common method of ex situ conservation for plant species that cannot be seed banked (i.e., exceptional species). Viability of living collections, and their value for future conservation efforts, can be limited without coordinated efforts to track and manage individuals across institutions. Using a pedigree-focused approach, the zoological community has established an inter-institutional infrastructure to support long-term viability of captive animal populations. We assessed the ability of this coordinated metacollection infrastructure to support the conservation of 4 plant species curated in living collections at multiple botanic gardens around the world. Limitations in current practices include the inability to compile, share, and analyze plant collections data at the individual level, as well as difficulty in tracking original provenance of ex situ material. The coordinated metacollection framework used by zoos can be adopted by the botanical community to improve conservation outcomes by minimizing the loss of genetic diversity in collections. We suggest actions to improve ex situ conservation of exceptional plant species, including developing a central database to aggregate data and track unique individuals of priority threatened species among institutions and adapting a pedigree-based population management tool that incorporates life-history aspects unique to plants. If approached collaboratively across regional, national, and global scales, these actions could transform ex situ conservation of threatened plant species.     

Evaluation of catalyzed and electrically heated filters for removal of particulate emissions from diesel-A- and JP-8-fueled engines

In-service diesel engines are a significant source of particulate matter (PM) emissions, and they have been subjected to increasingly strict emissions standards. Consequently, the wide-scale use of some type of particulate filter is expected. This study evaluated the effect of an Engelhard catalyzed soot filter (CSF) and a Rypos electrically heated soot filter on the emissions from in-service diesel engines in terms of PM mass, black carbon concentration, particle-bound polycyclic aromatic hydrocarbon concentration, and size distribution. Both filters capture PM. The CSF relies on the engine's exhaust to reach the catalyst regeneration temperature and oxidize soot, whereas the electrically heated filter contains a heating element to oxidize soot. The filters were installed on several military diesel engines. Particle concentrations and compositions were measured before and after installation of the filter and again after several months of operation. Generally, the CSF removed at least 90% of total PM, and the removal efficiency improved or remained constant after several months of operation. In contrast, the electrical filters removed 44-69% of PM mass. In addition to evaluating the soot filters, the sampling team also compared the results of several real-time particle measurement instruments to traditional filter measurements of total mass.     

Diuron occurrence and distribution in soil and surface and ground water associated with grass seed production

Little is known about the occurrence and distribution of the herbicide diuron [3-(3,4-dichlorophenyl)-1,1-dimethyl urea] in soil, ground water, and surface water in areas affected by grass-seed production. A field study was designed to investigate the occurrence and distribution of diuron and its transformation products at a poorly drained field site located along an intermittent tributary of Lake Creek in the southern Willamette Valley of Oregon. The experimental sites consisted of a field under commercial grass seed production with a cultivated riparian zone and a second site that was part of the same grass seed field but with a noncultivated riparian zone. Diuron and its transformation product DCPMU [3-(3,4-dichlorophenyl)-1-methylurea] were the only significant residues detected in this study. Concentrations of diuron in surface water declined from a maximum of 28 microg/L immediately following application to low levels that persisted as long as flow was present. Diuron and DCPMU concentrations in shallow ground water (15-36 cm below ground surface) were highest (2-13 microg/L) in the zone immediately adjacent (0.5 m) to Lake Creek and indicated the influence of stream water on shallow ground water near the stream. Diuron and DCPMU detected in soil prior to the second season's application indicated the persistence of diuron and DCPMU from the previous year's application. Surface runoff during the rainy season removes only a very small percentage (<1%) of the applied herbicide. In addition, no evidence was obtained for the downward transport of diuron or its transformation products to deep ground water.     

Habitat Improvements and Fish Community Response Associated with an Agricultural Two‐Stage Ditch in Mower County,Minnesota

Water quality and stream habitat in agricultural watersheds are under greater scrutiny as hydrologic pathways are altered to increase crop production. Ditches have been traditionally constructed to remove water from agricultural lands. Little attention has been placed on alternative ditch designs that are more stable and provide greater habitat diversity for wildlife and aquatic species. In 2009, 1.89 km of a conventional drainage ditch in Mower County, Minnesota, was converted to a two‐stage ditch (TSD) with small, adjacent floodplains to mimic a natural system. Cross section surveys, conducted pre‐ and post‐construction, generally indicate a stable channel with minor adjustments over time. Vegetation surveys showed differences in species composition and biomass between the slopes and the benches, with changes ongoing. Longitudinal surveys demonstrated a 12‐fold increase in depth variability. Fish habitat quality improved with well‐sorted gravel riffles and deeper pool habitat. The biological response to improved habitat quality was investigated using a Fish Index of Biological Integrity (FIBI). Our results show higher FIBI scores post‐construction with scores more similar to natural streams. In summary, the TSD demonstrated improvements in riparian and instream habitat quality and fish communities, which showed greater fish species richness, higher percentages of gravel spawning fish, and better FIBI scores. This type of management tool could benefit ditches in other regions where gradient and geology allow.     

Phytoremediation of a Petroleum‐Hydrocarbon Contaminated Shallow Aquifer in Elizabeth City,North Carolina,USA

A former bulk fuel terminal in North Carolina is a groundwater phytoremediation demonstration site where 3,250 hybrid poplars, willows, and pine trees were planted from 2006 to 2008 over approximately 579,000 L of residual gasoline, diesel, and jet fuel. Since 2011, the groundwater altitude is lower in the area with trees than outside the planted area. Soil‐gas analyses showed a 95 percent mass loss for total petroleum hydrocarbons (TPH) and a 99 percent mass loss for benzene, toluene, ethylbenzene, and xylenes (BTEX). BTEX and methyl tert‐butyl ether concentrations have decreased in groundwater. Interpolations of free‐phase, fuel product gauging data show reduced thicknesses across the site and pooling of fuel product where poplar biomass is greatest. Isolated clusters of tree mortalities have persisted in areas with high TPH and BTEX mass. Toxicity assays showed impaired water use for willows and poplars exposed to the site's fuel product, but Populus survival was higher than the willows or pines on‐site, even in a noncontaminated control area. All four Populus clones survived well at the site. © 2014 Wiley Periodicals, Inc.*