The Characterisation of Settled Dust by Scanning Electron Microscopy and Energy Dispersive X-ray Analysis

Settled dust has been collected inside the main foyers ofthree University buildings in Wolverhampton City Centre,U.K. Two of the three buildings are located in a streetcanyon used almost exclusively by heavy duty dieselvehicles. The dust was collected on adhesive carbonspectro-tabs to be in a form suitable for analysis byscanning electron microscope and energy dispersive X-rayanalysis. Using these analytical techniques, individualparticle analysis was undertaken for morphology andchemistry. Seasonal variations and variations due tolocation were observed in both the morphologicalmeasurements and chemical analysis. Many of the differencesappear attributable to the influence of road traffic, inparticular, the heavy duty diesel vehicles, travellingalong the street canyon.     

Why—and how to—benchmark for environmental excellence

Benchmarking your company'S environmental program against that of another company or organization is one of the more effective means of assuring it is on track toward environmental excellence. If used properly and objectively, it provides a means of gauging the progress of your environmental program while allowing both companies to benefit from new and innovative ideas for improvement. Benchmarking is capable of measuring program efficiency, program design, and program outputs. Benchmarking also provides environmental managers the unique opportunity of sharing successes and failures with respect to program integration into operations. This article describes the steps involved in designing and implementing benchmarking to assess the design of an overall environmental management program.     

Nitrogen and phosphorus status of soils and trophic state of lakes associated with forage-based beef cattle operations in Florida

Forage-based livestock systems have been implicated as major contributors to deteriorating water quality, particularly for phosphorus (P) from commercial fertilizers and manures affecting surface and ground water quality. Little information exists regarding possible magnitudes of nutrient losses from pastures that are managed for both grazing and hay production and how these might impact adjacent bodies of water. We examined the changes that have occurred in soil fertility levels of rhizoma peanut (Arachis glabrata Benth.)-based beef cattle pastures (n = 4) in Florida from 1988 to 2002. These pastures were managed for grazing in spring followed by haying in late summer and were fertilized annually with P (39 kg P2O5 ha(-1)) and K (68 kg K2O ha(-1)). Additionally, we investigated trends in water quality parameters and trophic state index (TSI) of lakes (n = 3) associated with beef cattle operations from 1993 to 2002. Overall, there was no spatial or temporal buildup of soil P and other crop nutrients despite the annual application of fertilizers and daily in-field loading of animal waste. In fact, soil fertility levels showed a declining trend for crop nutrient levels, especially soil P (y = 146.57 - 8.14 x year; r2= 0.75), even though the fields had a history of P fertilization and the cattle were rotated into the legume fields. Our results indicate that when nutrients are not applied in excess, cow-calf systems are slight exporters of P, K, Ca, and Mg through removal of cut hay. Water quality in lakes associated with cattle production was "good" (30-46 TSI) based on the Florida Water Quality Standard. These findings indicate that properly managed livestock operations may not be major contributors to excess loads of nutrients (especially P) in surface water.     

Acid rain: chemistry and transport

This review describes the more important features of the emission, chemistry, transport and deposition of pollutants involved in acid deposition. Global emissions, both natural and man-made, of sulphur and nitrogen oxides are discussed and examples of spatial distributions and trends over the last century presented. The more significant chemical and physical processes involved in the transformation of the primary emissions into their acidic end products are described, including a summary of the approximate timescales of the processes involved. Measurements and modelled calculations of spatial and temporal patterns in the deposition of acidic pollutants by both wet and dry pathways are presented.     

Reducing atrazine losses: water quality implications of alternative runoff control practices

Water quality is being affected by herbicides, some allegedly harmful to human health. Under scrutiny is atrazine (1-chloro-3-ethylamino-5-isopropylamino-2,4,6-triazine), a commonly used herbicide in corn (Zea mays L.) and sorghum [Sorghum bicolor (L.) Moench] production. Concentrations of soluble and adsorbed atrazine losses sometimes exceed the safe drinking water standard of 3 microg L(-1) established by the USEPA. This study assesses the protective implications of runoff control structures and alternative crop farming practices to minimize atrazine losses. Using a computerized simulation model, APEX, the following four practices were the most effective with respect to the average atrazine loss as a percent of the amount applied: (i) constructing sediment ponds, 0.09%; (ii) establishing grass filter strips, 0.14%; (iii) banding a 25% rate of atrazine, 0.40%; and (iv) constructing wetlands, 0.45%. Other atrazine runoff management options, including adoption of alternative tillage practices such as conservation and no-till as well as splitting applications between fall and spring, were marginally effective.     

Pilot‐scale evaluation using bioaugmentation to enhance PCE dissolution at dover AFB national test site

An Interstate Technology and Regulatory Council (ITRC) forum was recently held that focused on six case studies in which bioremediation of dense nonaqueous‐phase liquids (DNAPLs) was performed; the objective was to demonstrate that there is credible evidence for bioremediation as a viable environmental remediation technology. The first two case studies from the forum have been previously published; this third case study involves a pilot‐scale demonstration that investigated the effects of biological activity on enhancing dissolution of an emplaced tetrachloroethene (PCE) DNAPL source. It used a controlled‐release test cell with PCE as the primary DNAPL in a porous media groundwater system. Both laboratory tests and a field‐scale pilot test demonstrated that bioaugmentation can stimulate complete dechlorination to a nontoxic end product and that the mass flux from a source zone increases when biological dehalorespiration activity is enhanced through nutrient (electron donor) addition and bioaugmentation. All project goals were met. Important achievements include demonstrating the ability to degrade a PCE DNAPL source to ethene and obtaining significant information on the impacts to the microbial populations and corresponding isotope enrichments during biodegradation of a source area. © 2007 Wiley Periodicals, Inc.     

A framework for assessing the sustainability of brownfield developments

In England, the development of urban brownfield sites is a significant planning policy aimed at supporting urban regeneration and protecting the countryside. Brownfield sites are required, in policy, to be developed in a sustainable way. However, determining what this means in practice is unclear. This paper presents a framework for assessing the sustainability of brownfield developments, devised to clarify the stakeholders in land reuse and establish how sustainability can be achieved on reused sites. The framework has been used in research investigating the sustainability of five brownfield developments in England. The performance of the framework in this research is assessed and its potential practical use outlined.     

SEDIMENT ROUTING FOR AGRICULTURAL WATERSHEDS1

ABSTRACT: A sediment routing technique was developed to route sediment yield from small watersheds through streams and valleys to the outlet of large watersheds. The technique is based on the modified universal sol loss equation and a first order decay function of travel time and particle size. Deposition is dependent upon settling velocities of sediment particles, travel time, and the amount of sediment in suspension. Sediment routing increases sediment yield prediction accuracy and allows determination of subwatershed contributions to the total sediment yield. Also, the locations and amounts of floodplain scour and deposition can be predicted. Another advantage of sediment routing is that measured sediment yield data are not required. The procedure performed satisfactorily in test routings on two Texas blackland watersheds Sediment routing will be useful in flood control evaluation, reservoir and channel design, water quality calculations, environmental impact assessment, and land-use planning.     

Can synchronous spawning be predicted from environmental parameters? A case study of the lugworm Arenicola marina

The annual epidemic spawning period of a Scottish population of Arenicola marina (L.) has been recorded over a period of 13 yr. This population spawns between mid-October and mid-November in a discrete spawning event over a period of 4 to 5 d. Endocrine manipulation experiments showed that spawning is induced in females only if sufficient titres of PMH (prostomial maturation hormone) are present in the prostomia. These levels are attained during the 2 to 3 wk prior to the natural spawning date. The East Sands, St. Andrews population always spawns during periods of spring tides regardless of tidal amplitude or whether they are full- or new-moon tides. Meteorological data, including sea-temperature data were collected for each year, and correlation of the environmental data with spawning time was attempted. Correlation of spawning times with weather patterns showed that mean daily air pressures were significantly higher during the spawning period than from September to November as a whole. Evidence also suggests that a reduction in sea temperature is required prior to spawning. A significant moderate negative correlation was found between May to July air temperatures and spawning date, suggesting that higher May to July temperatures may induce early spawning. Daily rainfall and wind speed were also lower during the spawning period, but not significantly so. These results indicate that air pressure (or changes therein) may act as a final spawning cue, and the advantages of this are discussed in relation to fertilization success. A model of the interplay between environmental parameters and the endocrine mechanisms controlling the induction of spawning is proposed. Higher than average summer temperatures may advance gametogenesis to bring the population into a state of maturity (full-size oocytes, well-developed sperm morulae), and may also advance spawning time. Once the population has completed gametogenesis, a drop in sea temperature is then required to trigger an increase in endocrine titres within the prostomium, without which spawning cannot be induced by prostomial injection. The population spawns on spring tides; however a lack of clement weather coinciding with the spring tide will result in population-wide spawning being aborted, as in 1996. Clement weather (high pressure, low rainfall and wind speed) in conjunction with spring tides permits spawning to proceed to completion. Received: 21 June 1999 / Accepted: 25 January 2000