Environmentally friendly assessment of organic compound bioaccessibility using sub-critical water

The evaluation of microbial availability of contaminants is of high importance for better reflecting the processes governing contaminant fate in soil and for establishing the risk associated with contaminated sites. A sub-critical water extraction technique was assessed for its potential to determine the microbially degradable fraction of [¹⁴C]phenanthrene-associated activity in two dissimilar soils at three different ageing times (14, 28 and 49 days). For the majority of determinations, no significant (p > 0.05) difference between sub-critical water-extracted ¹⁴C-activity at 160 °C and the fraction mineralized by catabolically active Pseudomonas sp. was observed. Collectively, the results suggested that the sub-critical water extraction technique was an appropriate technique for predicting the biodegradable fraction of phenanthrene-associated ¹⁴C-activity in dissimilar soils following increasing soil-contaminant contact time.     

Assessing biodegradation potential of PAHs in complex multi-contaminant matrices

This study sought to extend validation of a cyclodextrin based extraction method for the assessment of PAH-biodegradation potential to complex multi-contaminant matrices. To this end, four reference materials (RMs) were produced by blending, in different proportions, soils impacted with diesel, lubricating oil and spent oxide. These reference materials had modest ∑PAH (16 US EPA) concentrations that ranged from 5.6 ± 0.5 to 44.4 ± 4.5 mg kg⁻¹. However, extractable petroleum hydrocarbon (EPH) concentrations were comparatively high (up to 2520 ± 204 mg kg⁻¹). To complement these RMs, two further soils from a municipal gas plant (MGP) with highly elevated concentration of PAHs ranging from 877 ± 52 to 2620 ± 344 mg kg⁻¹ were also tested. Results showed, regardless of matrix complexity, that PAH biodegradation within the four RM substrates, and two MGP soils correlated well with biodegradation predicted by hydroxypropyl-β-cyclodextrin (HPCD) extraction.     

Quality assured measurements of animal building emissions: odor concentrations

Standard protocols for sampling and measuring odor emissions from livestock buildings are needed to guide scientists, consultants, regulators, and policy-makers. A federally funded, multistate project has conducted field studies in six states to measure emissions of odor, coarse particulate matter (PM(10)), total suspended particulates, hydrogen sulfide, ammonia, and carbon dioxide from swine and poultry production buildings. The focus of this paper is on the intermittent measurement of odor concentrations at nearly identical pairs of buildings in each state and on protocols to minimize variations in these measurements. Air was collected from pig and poultry barns in small (10 L) Tedlar bags through a gas sampling system located in an instrument trailer housing gas and dust analyzers. The samples were analyzed within 30 hr by a dynamic dilution forced-choice olfactometer (a dilution apparatus). The olfactometers (AC'SCENT International Olfactometer, St. Croix Sensory, Inc.) used by all participating laboratories meet the olfactometry standards (American Society for Testing and Materials and European Committee for Standardization [CEN]) in the United States and Europe. Trained panelists (four to eight) at each laboratory measured odor concentrations (dilution to thresholds [DT]) from the bag samples. Odor emissions were calculated by multiplying odor concentration differences between inlet and outlet air by standardized (20 degrees C and 1 atm) building airflow rates.     

An Australasian model license reassessment procedure for identifying potentially unsafe drivers

Most licensing jurisdictions in Australia currently employ age-based assessment programs as a means to manage older driver safety, yet available evidence suggests that these programs have no safety benefits. This paper describes a community referral-based model license re assessment procedure for identifying and assessing potentially unsafe drivers. While the model was primarily developed for assessing older driver fitness to drive, it could be applicable to other forms of driver impairment associated with increased crash risk. It includes a three-tier process of assessment, involving the use of validated and relevant assessment instruments. A case is argued that this process is a more systematic, transparent and effective process for managing older driver safety and thus more likely to be widely acceptable to the target community and licensing authorities than age-based practices.     

The influence of organic acids in relation to acid deposition in controlling the acidity of soil and stream waters on a seasonal basis

Much uncertainty still exists regarding the relative importance of organic acids in relation to acid deposition in controlling the acidity of soil and surface waters. This paper contributes to this debate by presenting analysis of seasonal variations in atmospheric deposition, soil solution and stream water chemistry for two UK headwater catchments with contrasting soils. Acid neutralising capacity (ANC), dissolved organic carbon (DOC) concentrations and the Na:Cl ratio of soil and stream waters displayed strong seasonal patterns with little seasonal variation observed in soil water pH. These patterns, plus the strong relationships between ANC, Cl and DOC, suggest that cation exchange and seasonal changes in the production of DOC and seasalt deposition are driving a shift in the proportion of acidity attributable to strong acid anions, from atmospheric deposition, during winter to predominantly organic acids in summer.     

肉类加工厂的环境实践：新西兰经验

评论了新西兰肉类加工业的演变,尤其与环境影响有关的演变.尽管在废物削减、副产物回收和加工方面取得很大进展,但肉类加工继续产生大量废物.因此,有颇多的废物削减机会存在.与环境有关的程序和标准,受到国际上对成本-有效性的需要、国家法规以及进口国法规达标的需要、和各种各样商业质量要求影响.按照新法规,要求新西兰肉类加工者编制并实施风险管理计划.     

Regional governance and hazard information: the role of co-ordinated risk assessment and regional spatial accounting in wildfire hazard mitigation

With the threat of wildfire hanging over many communities in the Western and Southern United States, wildfire mitigation is evolving into a significant public responsibility for rural and urban edge county governments. Regional governance is an important piece of the effort to reduce wildfire risks although still weakly developed as a policy arena. This project explores two dimensions in which planning support systems can support regional governance: assessing patterns of wildfire risk accumulation; and, evaluating land use planning alternatives and their effects on cumulative risk levels. These tools are examined for regional governance using a prototype planning information system, the Alternative Growth Futures (AGF) tool, a scenario-building approach developed at the University of Colorado Denver. The project develops a hybrid urban growth model that integrates logistic regression techniques and methods for simulation of growth alternatives. This model is used to evaluate the attractiveness of undeveloped building sites with respect to natural amenities, distance to primary urban services and site characteristics such as slope. The model and scenario-testing framework are reasonably robust and suggest that regional spatial accounting methods have potential as a framework for inter-governmental and public discussion around wildfire planning.     

Panel Discussion on Energy Efficiency

The session on energy efficiency had no formal presentations and was organized as a panel discussion with four panelists. It was concluded that energy efficiency and saving measures on the short term is the most effective way to contribute to a sustainable energy system. Measures to improve and encourage energy efficiency should be implemented at all levels; municipal/local, national and super-national. Prices can be an effective instrument but need to be combined with systemic level measures. The transport sector was identified as the one with largest near future potential for increased energy efficiency. Agriculture and food is also an area with very large energy consumption and large potential for increased energy efficiency. The global population issue is yet another relevant, challenging and complex issue. It was noted that energy audits for end users in business and society increase awareness and insights into what they pay for, and they are likely to promote actions to save energy. Many measures are believed to suffer from Jevin’s paradox, i.e., that more efficient use of energy just leads to more energy consumption somewhere else. Many examples were given, however, where this does not happen. Another point put forward was that measures to make the energy system more efficient do not only mean constraints and regulations but also create great opportunities for market actors and societies.     

Metal toxicity in a sediment-dwelling polychaete: Threshold body concentrations or overwhelming accumulation rates?

We followed the net accumulation of As, Cu and Zn in the deposit-feeding polychaete Arenicola marina exposed in the laboratory to natural metal-contaminated sediments, one exposure leading to mass mortality between day 10 and 20, and the other not causing lethality over a period of 60 days of exposure. The worms showed lower total accumulated metal concentrations just before mortality occurred (<20 days) at the lethal exposure, than after 30 days of exposure to sediments not causing mortality. Moreover rates of accumulation of As, Cu and Zn were significantly higher in the lethal exposure than in the sublethal exposure. Our results show that it is not possible to link mortality to a critical total body concentration, and we add to a growing body of literature indicating that metal toxicity occurs when organisms cannot cope with overwhelming influx and subsequent accumulation rates.     

Wellbore integrity analysis of a natural CO2 producer

Long-term integrity of existing wells in a CO₂-rich environment is essential for ensuring that geological sequestration of CO₂ will be an effective technology for mitigating greenhouse gas-induced climate change. The potential for wellbore leakage depends in part on the quality of the original construction as well as geochemical and geomechanical stresses that occur over its life-cycle. Field data are essential for assessing the integrated effect of these factors and their impact on wellbore integrity, defined as the maintenance of isolation between subsurface intervals. In this report, we investigate a 30-year-old well from a natural CO₂ production reservoir using a suite of downhole and laboratory tests to characterize isolation performance.These tests included mineralogical and hydrological characterization of 10 core samples of casing/cement/formation, wireline surveys to evaluate well conditions, fluid samples and an in situ permeability test. We find evidence for CO₂ migration in the occurrence of carbonated cement and calculate that the effective permeability of an 11′-region of the wellbore barrier system was between 0.5 and 1 milliDarcy. Despite these observations, we find that the amount of fluid migration along the wellbore was probably small because of several factors: the amount of carbonation decreased with distance from the reservoir, cement permeability was low (0.3–30 microDarcy), the cement–casing and cement-formation interfaces were tight, the casing was not corroded, fluid samples lacked CO₂, and the pressure gradient between reservoir and caprock was maintained. We conclude that the barrier system has ultimately performed well over the last 3 decades. These results will be used as part of a broader effort to develop a long-term predictive simulation tool to assess wellbore integrity performance in CO₂ storage sites.