Effects of ethanol as an additive on odor detection thresholds of Alaskan gasolines at sub-arctic temperatures

This study evaluated the odor thresholds of two Alaskan unleaded gasolines, Tesoro and Mapco, and their ethanol oxyfuel blends at typical winter temperatures of −25°F, O°F, and +25°F. We found that temperature had a slight but variable effect on both odor thresholds and headspace composition. When 10% ethanol was added to Tesoro, a refined gasoline, there was a significant lowering (83%) of the odor detection threshold, i.e., an increase in human sensitivity to the odor. Vapors formulated from 10% ethanol-Mapco gasoline mixtures did not change the odor detection threshold. This study supports the hypothesis that the base gasolines interact variably with oxygenate additives. Ethanol appears to behave in a dissimilar manner when added to gasolines with different aromatic content.     

Can adsorption isotherms predict sediment bioavailability?

The adsorption and desorption of 2,4-dichlorophenol (DCP) and pentachlorophenol (PCP) were studied for a range of synthetic particles, a dimethylditallowammonium exchanged clay and a natural sediment. The synthetic particles were Dowex 1X8400, Toyopearl Phenyl 650M and Toyopearl SP 650M. The bioaccumulation of the DCP and PCP from these particles was then studied using the oligochaete, Lumbriculus variegatus. There is a correlation between contaminant-particle interactions, as determined from adsorption and desorption isotherms, and bioaccumulation. Bioaccumulation by L. variegatus was found to be highest from the systems where differences in the classification of adsorption and desorption isotherms were observed.     

Cool temperature performance of a wheat straw biofilter for treating dairy wastewater

A wheat straw biofilter was evaluated for attenuating pollutants in dairy (milkhouse and milking parlor) wastewater. During the 14-day study, the biofilter was operated in a sequential aerobic-anaerobic mode in a temperature range of 8-14 degrees C. While the biofilter was very effective (89% removal) in attenuating total suspended solids and moderately effective (76% removal) in attenuating oil and grease, its effectiveness in attenuating chemical oxygen demand was low (37% removal). The biofilter was ineffective in attenuating nitrate, while its effectiveness in attenuating ammonium (20% removal) and total Kjeldahl nitrogen (15% removal) was low. The biofilter was not effective in attenuating ortho-phosphate, total phosphorus, and fecal coliform. Though microbial degradation accounted for some pollutant removal, filtration seemed to be the primary mechanism. Lower temperature of operation and high oil and grease concentration (that reduced nutrient transfer to the biofilm) decreased microbial activity, reducing pollutant attenuation. Biofilter performance could be enhanced by using residual heat in the wastewater to raise the operating temperature of the biofilter and by removing oil and grease prior to applying the wastewater to the biofilter.     

Potential risk to wood storks (Mycteria americana) from mercury in Carolina Bay fish

Carolina bays are freshwater wetlands that serve as important feeding habitats for the endangered wood stork (Mycteria americana). Water levels in these bays fluctuate greatly and tend to be acidic and rich in dissolved organic carbon (DOC), factors that favor mercury (Hg) methylation and bioaccumulation in fish. To assess potential risks to wood storks consuming mercury contaminated fish in bays, we sampled fish from 10 bays on the Savannah River Site (SRS), South Carolina, an area with documented use by wood storks. Whole body mercury concentrations in 258 fishes of three species (Erimyzon sucetta, Acantharchuspomotis and Esox americanus) commonly consumed by wood storks were determined. Risk factors for nestlings and free-ranging adults were calculated using published no and lowest observable adverse effect concentration (NOAEC and LOAEC) values for birds. Fish from higher trophic levels and those from wetlands with relatively shallow maximum depths and fluctuating water levels were more likely to exceed NOAEC and LOAEC values. Calculation of exposure rates of nestling wood storks indicated they are at highest risk during the first 10 days of the nestling period. These calculations suggest that there is potential concern for wood storks foraging in relatively shallow bays with fluctuating water levels, even though there is no obvious local source of mercury to these wetlands.     

Distribution and rate of disappearance of fluorene in pond ecosystems

Fluorene, an energy related polynuclear aromatic hydrocarbon, was applied to several experimental pond ecosystems to effect concentrations of 0.12, 0.5, 2.0, 5.0, and 10.0 mg/L. Water, benthic sediment, and rooted macrophytes were monitored for fluorene residues for 56 days after application. Most of the fluorene at concentrations greater than its water solubility appeared to sublime from the surface of the ponds. The rate of disappearance of fluorene from the water decreased as the application rate increased. This reduction was linked to high concentrations and a flux of fluorene from benthic sediments, macrophytes, and pond surfaces to water columns. Several parameters of photosynthetic primary production were statistically linked to the accelerated disappearance of fluorene from the water.     

Acute temperature dependency in the cleansing of tarry feathers utilizing magnetic particles

We have conducted temperature-dependent studies on the removal of a solidified tarry residue from feathers using magnetic particles. These studies demonstrate an acute temperature dependency whereby no contaminant at all is removed below a certain temperature but, at and above this temperature, the removal rapidly approaches 100%. Significantly, this temperature is well below the temperature at which the tarry residue becomes a flowing liquid. This demonstrates that it is possible for magnetic cleansing to remove up to 100% of tarry residue from feathers under temperature conditions that would be benign to a bird.     

Benchmarking environmental audit programs: Best practices and biggest challenges

As Total Quality Management (TQM) has become an important concept in learning how to manage environmental, health, and safety audit programs more effectively, an especially useful. TQM tool has been competitive benchmarking. Companies are using benchmarking studies to identify “best practices” that could be incorporated into their programs. In conducting benchmarking studies, evaluators often also identify the biggest common challenges facing audit program managers. This article discusses these best practices and biggest challenges associated with environmental audit programs. The conclusions are based on a number of benchmarking studies and third-party evaluations of corporate audit programs. As the sources are necessarily limited to the author's own experiences, there are no doubt many other specific best practices that are not discussed in this article. These will surface over time.     

Feeding and aggressive behaviours in juvenile coho salmon (Oncorhynchus kisutch) under chemically-mediated risk of predation

Summary Juvenile coho salmon (Oncorhynchus kisutch) spend the first year of their lives in their natal streams, where they may often hold feeding territories. They also face significant risk of predation by birds and fish, and should alter their behaviour to reduce risk of mortality when these predators are present. Although there is laboratory evidence that coho react to predator visual stimuli, chemoreception of avian predator presence has not previously been reported. We tested the influence of chemical stimuli of common merganser (Mergus merganser), preying on juvenile coho, on two aspects of coho territorial behaviour, foraging and aggression, in flow-through aquaria. After a mixture of merganser- and coho-conditioned water was introduced into the system, juvenile coho significantly reduced their attack distance on drifting prey. The fish also significantly decreased their aggressive behaviour directed towards mirrors (total number of acts, intensity of acts and time spent) when the same odour was present. They did not change their behaviour in either experiment after control introductions of water treated with fish alone. These results are interpreted within the framework of a trade-off between juvenile growth and mortality.     

The birth and death of a local initiative: Challenges of and lessons from the 'Bakassi' Vigilante Group in Southeastern Nigeria

Violent crime has plagued Nigerian society. It is in this context that some traders in the southeastern part of the country put together the Bakassi Boys—a security apparatus to parallel the Nigeria Police. The Bakassi attracted both praise and criticism. In this paper, I review the Bakassi phenomenon as a local initiative that tried to integrate elements of the traditional cosmology and ways of policing in response to the escalation of crime. The Bakassi being a child of crisis, there were flaws in their operation. By exploring the lessons that one can learn from the Bakassi experiment and outlining the challenges that it poses, one might hope to harness the lessons of a local initiative that failed in order to respond better to the socio-political issues that engineered its emergence.