Adaptive Management of Flows in the Lower Roanoke River, North Carolina, USA

The lower Roanoke River in North Carolina, USA, has been regulated by a series of dams since the 1950s. This river and its floodplain have been identified by The Nature Conservancy, the US Fish and Wildlife Service, and the State of North Carolina as critical resources for the conservation of bottomland hardwoods and other riparian and in-stream biota and communities. Upstream dams are causing extended floods in the growing season for bottomland hardwood forests, threatening their survival. A coalition of stakeholders including public agencies and private organizations is cooperating with the dam managers to establish an active adaptive management program to reduce the negative impacts of flow regulation, especially extended growing season inundation, on these conservation targets. We introduce the lower Roanoke River, describe the regulatory context for negotiating towards an active adaptive management program, present our conservation objective for bottomland hardwoods, and describe investigations in which we successfully employed a series of models to develop testable management hypotheses. We propose adaptive management strategies that we believe will enable the bottomland hardwoods to regenerate and support their associated biota and that are reasonable, flexible, and economically sustainable.     

UN/ECE ICP Materials Dose-response Functions for the Multi-pollutant Situation

A “multi-pollutant exposure programme” reflecting the new pollution situation where SO₂ is no longer the dominating pollutant has been performed by the International Co-operative Programme on Effects on Materials, including Historic and Cultural Monuments (ICP Materials) within the activities of the Convention on Long-range Transboundary Air Pollution. The main results obtained in the period 1997–2003 are summarised. Dose-response functions are presented for carbon steel, zinc, copper, bronze and limestone. Parameters involved in the functions include besides SO₂ and pH, which were included in the previously developed functions from ICP Materials, also the effect of particulate matter and HNO₃.     

Conservation Considerations for a Management Measure: An Integrated Approach to Hare Rearing and Release

Wildlife managers are challenged with the task of deciding whether a management measure is appropriate or not, and furthermore they have to convince others about the merits of their decision. Population decline of some hare species (genus Lepus) has resulted in their Red Listing and conservation measures are being undertaken. Release or restocking is a frequent measure in some countries, and thousands of hares are released annually, mainly for hunting purposes. These hares can be obtained by either intensive or extensive rearing or translocation of the wild animals. Each method entails difficulties and different survival rates in the wild. Survival rates in the wild are low for hares intensively reared in cages but are higher for hares reared extensively in enclosures and wild translocated hares. The benefits of the hare release practice are significantly lower than the action’s implementation cost. Hare releases have not increased significantly the wild hare population or the hunting harvest in areas where the practice has been applied. The risk of genetic and evolutionary degradation and pathogen transmission is possible in wild populations. The need for wise management of this practice is evident and the term ‘Permitted Transferring Units’ should be introduced to denote regions where hares should not be transferred for rearing and release.     

A new approach for facility siting using mapping risks on a plant grid area and optimization

The present work is focused on developing a methodology to find the optimal placement of a hazardous process unit and other facilities using optimization theory while considering a risk map in the plant area. Incidents can have possible consequences resulting from flammable gas releases, which can be evaluated by using consequence modeling programs. The probability of each incident can be derived from initial leak hole size estimation through event tree analysis. In this methodology the plant area was divided into square grids and risk scores were estimated for each grid. The overall cost is a function of the probable cost of property damage due to fires or explosions and the interconnection cost including piping, cable, and management. The proposed approach uses a mixed integer linear optimization programming (MILP) that identifies attractive locations by minimizing the overall cost. A case study is presented for a hexane–heptane separation facility that considers the meteorological data for the given area in order to show the applicability of the proposed methodology. Results from this study will be useful in assisting the selection of locations for facilities and for risk management.     

An approach for risk reduction (methodology) based on optimizing the facility layout and siting in toxic gas release scenarios

In this work, a new approach to optimize facility layout for toxic release is presented. By integrating a risk analysis in the optimization formulation, we propose a safer assignment for facility layout and siting. Accompanying with the economical concepts used in a plant layout, the new model considers the cost of willing to avoid a fatality, i.e. the potential injury cost due to accidents associated with toxic release near residential areas. The proposed formulation incorporates a real meteorological data to calculate the injury risk through the probit model and Monte Carlo simulation using dense gas dispersion modeling (DEGADIS). The overall problem was initially modeled as a disjunctive program where the coordinates of each facility and cost-related variables are the main unknowns. Then, the convex hull approach was used to reformulate the problem as a Mixed Integer Non-Linear Program (MINLP) that identifies potential layouts by minimizing overall costs. This approach gives the coordinates of each facility, and estimates for the total length of pipes, the land area, and the selection of safety devices. Finally, the 3D-computational fluid dynamics (CFD) was used to compare between the initial layout and the final layout. Moreover, analyses of separation distances fr2om hazard facilities and hindrance effects will be discussed based on the approach used in this work.     

Desorption characteristics of kaolin clay contaminated with zinc from electrokinetic soil processing

A number of bench scale laboratory column tests were carried out using a newly designed and developed electrokinetic cell to investigate the fundamental behavior of zinc-spiked kaolin clay subjected to an electric field. Laboratory investigations focused on (i) zinc migration by the combined effects of electromigration and electro-osmosis and (ii) the electrically induced desorption characteristics of zinc-contaminated kaolin that occurred during processing. The correlations of the applied voltage gradient, electro-osmotic flow rate, and the development of a pH gradient were examined and evaluated. The results showed that the removal efficiency was high during the early stage of processing due to rapid desorption by electrokinetic effects in the cathode region. However, the majority of zinc migrating from the anode was precipitated due to the high pH environment in the cathode region.     

Copper bioaccumulation,photosystem II functioning,and oxidative stress in the seagrass <Emphasis Type="Italic">Cymodocea nodosa</Emphasis> exposed to copper oxide nanoparticles

Photosynthetic activity, oxidative stress, and Cu bioaccumulation in the seagrass Cymodocea nodosa were assessed 4, 12, 24, 48, and 72 h after exposure to two copper oxide nanoparticle (CuO NP) concentrations (5 and 10 mg L^?1). CuO NPs were characterized by scanning electron microscopy (SEM) and dynamic light scattering measurements (DLS). Chlorophyll fluorescence analysis was applied to detect photosystem II (PSII) functionality, while the Cu accumulation kinetics into the leaf blades was fitted to the Michaelis-Menten equation. The uptake kinetics was rapid during the first 4 h of exposure and reached an equilibrium state after 10 h exposure to 10 mg L^?1 and after 27 h to 5 mg L^?1 CuO NPs. As a result, 4-h treatment with 5 mg L^?1 CuO NPs, decreased the quantum yield of PS II photochemistry (Φ _PSΙΙ ) with a parallel increase in the regulated non-photochemical energy loss in PSII (Φ _NPQ ). However, the photoprotective dissipation of excess absorbed light energy as heat, through the process of non-photochemical quenching (NPQ), did not maintain the same fraction of open reaction centers (q _p ) as in control plants. This reduced number of open reaction centers resulted in a significant increase of H₂O₂ production in the leaf veins serving possibly as an antioxidant defense signal. Twenty-four-hour treatment had no significant effect on Φ _PSΙΙ and q _p compared to controls. However, 24 h exposure to 5 mg L^?1 CuO NPs increased the quantum yield of non-regulated energy loss in PSII (Φ _NO ), and thus the formation of singlet oxygen (¹O₂) via the triplet state of chlorophyll, possible because the uptake kinetics had not yet reached the equilibrium state as did 10 mg L^?1. Longer-duration treatment (48 and 72 h) had less effect on the allocation of absorbed light energy at PSII and the fraction of open reaction centers, compared to 4-h treatment, suggesting the function of a stress defense mechanism. The response of C. nodosa leaves to CuO NPs fits the “Threshold for Tolerance Model” with a threshold time (more than 4 h) required for induction of a stress defense mechanism, through H₂O₂ production.     

Magnetic signature,geochemistry, and oral bioaccessibility of “technogenic” metals in contaminated industrial soils from Sindos Industrial Area,Northern Greece

The objective of this study was to assess the contamination level of potentially harmful elements (PHEs) in industrial soils and how this relates to environmental magnetism. Moreover, emphasis was given to the determination of the potential mobile fractions of typically “technogenic” metals. Therefore, magnetic and geochemical parameters were determined in topsoils (0–20 cm) collected around a chemical industry in Sindos Industrial Area, Thessaloniki, Greece. Soil samples were presented significantly enriched in “technogenic” metals such Cd, Pb, and Zn, while cases of severe soil contamination were observed in sampling sites north-west of the industrial unit. Contents of Cd, Cr, Cu, Ni, Pb, Mo, Sb, Sn, and Zn in soils and pollution load index (PLI) were highly correlated with mass specific magnetic susceptibility (χ _lf). Similarly, enrichment factor (EF) and geoaccumulation index (I _geo) for “technogenic” Pb and Zn exhibited high positive correlation factors with χ _lf. Principal component analysis (PCA) classified PHEs along with the magnetic variable (χ _lf) into a common group indicating anthropogenic influence. The water extractable concentrations were substantially low, while the descending order of UBM (Unified BARGE Method) extractable concentrations in the gastric phase was Zn > Pb > As > Cd, yet Cd showed the highest bioaccessibility (almost 95%).