A Method for Improving the Management of Controversial Wetland

Valley bottom wetlands in agricultural landscapes often are neglected in national and regional wetland inventories. Although these areas are small, located in the bottomlands of the headwater catchments, and scattered in the rural landscape, they strongly influence hydrology, water quality, and biodiversity over the whole catchment area. Valley bottom wetlands often are considered as controversial wetlands. Awareness of the functional role of wetlands is increasing, in parallel with their progressive disappearance in intensive farming landscapes. The need to improve tools for controlling wetland management is a primary consideration for decision makers and land users. This article proposes a method for the inventory of valley bottom wetlands. The method is based on the functional analysis of potential, existing, and efficient valley bottom wetlands (the PEEW approach). Several indicators are proposed for checking the validity of such an approach. Potential wetlands are delineated by means of a topographic index using topographic and pedoclimatic criteria computed from a Digital Elevation Model and easily accessible databases. Existing wetlands are identified from observed surface moisture, the presence of specific wetland vegetation, or soil feature criteria. Efficient wetlands are defined through a given function, such as flow or pollutant regulation or biodiversity control. An analysis of areas at the limits between potential, existing, and efficient wetlands highlights land cultivated or drained in the past, which currently represents negotiating areas in which rehabilitation and other intended management actions can be implemented.     

Evolution of iron speciation during hydration of C4AF

It is now well accepted and demonstrated that calcium silicate, calcium aluminate and calcium sulfo aluminate (ettringite, AFm) phases exhibit a good capability to fix metals and metalloids. Unfortunately the role of minor phases and especially calcium-ferric aluminate phase, shorthand C4AF is not well defined. In other systems like in soils or sediments iron phases play a key role in the fixation of pollutant. In cement sorption isotherms, indicated that various metals can be retained by the C4AF hydrated products. Therefore the capabilities of those phase to retain heavy metal should not be neglected. Previous investigations have shown that the minerals formed during the hydration of C4AF are similar to those formed from C3A (pure tri-calcium aluminate) under comparable conditions. Nevertheless no investigation was conducted at the molecular level and there is still a controversy whether Fe substitutes for Al in the hydrated minerals in whole or in part, or if it forms FeOOH clusters scattered throughout the matrix. In this context we have conducted XAS experiments using synchrotron radiation. It was found that the hydration of C4AF forms C3AH6 (hydrogarnet) in which Fe randomly substitutes for Al as well as an amorphous FeOOH phase. Intermediate products like AFm (i.e., an ill organized lamellar phase) are also formed but rapidly evolve to C3AH6; iron does not seem to be incorporated in the AFm structure.     

Effect of cadmium-bearing sewage sludge on crop plants and microorganisms in two different soils

The metal-binding capacities of two regional soils of southern Italy were evaluated. A volcanic soil and a sample of “terra rossa” were treated with sewage sludge spiked with CdSO₄ to obtain 0, 2, 4, 8 and 16 ppm of total cadmium in the soil. Cadmium uptake and cadmium effects on dry-matter production of rye grass, spinach, dwarf bean and radish grown in the two soils and the effects of cadmium on soil microflora were investigated. Plant and microbial responses were considered in relation to three different analytical methods for evaluating the biologically-effective concentration of cadmium in soil.     

Artificial radioactivity in Cumbria: Summary of an assessment by measurement and modelling

At the Harwell laboratory, the distributions of the artificial radionuclides discharged by British Nuclear Fuels at Sellafield have been measured within Cumbria, with particular emphasis on the transfer between environmental media. The results of the measurements have been incorporated into a model of the Cumbrian environment.The object of this work is to estimate the radiological impact upon man by exploring the pathways leading to external irradiation, to inhalation and to the ingestion of foodstuffs.Distributions have been established for caesium-137, plutonium isotopes and americium-241. Transfer from sea to land, of actinide radioactivity discharged to the sea, occures on a very small scale. The relative contributions to deposition and airborne radioactivity from sea-to-land transfer, fallout from nuclear weapons testing and atmospheric releases from Sellafield are compared. The dose resulting from sea-to-land transfer of actinides to a resident of Seascale peaked in 1973 at less than 1% of the ICRP annual limit for the general public and should fall steadily up to the year 2000.     

Consequence prediction for dust explosions involving interconnected vessels using computational fluid dynamics modeling

Combustible dust explosions continue to present a significant threat toward operating personnel and pneumatic conveyance equipment in a wide variety of processing industries. Following ignition of suspended fuel within a primary enclosure volume, propagation of flame and pressure fronts toward upstream or downstream interconnected enclosures can result in devastating secondary explosions if not impeded through an appropriate isolation mechanism. In such occurrences, an accelerated flame front may result in flame jet ignition within the secondary vessel, greatly increasing the overall explosion severity. Unlike an isolated deflagration event with quantifiable reduced pressures (vent sizing according to NFPA 68 guidance), oscillation of pressure between primary and secondary process vessels leads to uncertain overpressure effects. Dependent on details of the application such as relative enclosure volumes, relief area, fuel type, suspended concentration, duct size, and duct length, the maximum system pressure in both interconnected vessels can be unpredictable. This study proposes the use of FLame ACceleration Simulator (FLACS) computational fluid dynamics (CFD) modeling to provide reliable consequence predictions for specific case scenarios of dust deflagrations involving interconnected equipment. Required minimum supplement to the originally calculated relief area (A_v) was determined through iterative simulation, allowing for reduced explosion pressures (P_red) to be maintained below theoretical enclosure design strengths (P_es).     

Invasion costs,impacts, and human agency: response to Sagoff 2020

Article impact statement: In an era of profound biodiversity crisis, invasion costs, invader impacts, and human agency should not be dismissed.     

Clays and modified clays in remediating environmental pollutants

Environmental Science and Pollution Research -     

Use of a non-planning driving background change methodology to assess the land-use planning impact on the environment

The implementation of land-use planning (LUP) impacts on the environment and may degrade regional environmental quality due to the changes in land-use patterns. To minimize the environmental impact of non-LUP driven (NPD) land-use background changes (LUBC), we propose an NPD land-use background change (NPD-LUBC) methodology to improve the LUP environmental impact assessment (LUPEA) process. With the application of the state-impact-state (SIS) framework and spatial information technologies including remote sensing and geographic information system (GIS), the methodology was tested on the eastern Chinese city of Lianyungang. The results indicate that (1) our proposed methodology is capable of distinguishing the environmental impact in implementing a target LUP, i.e. a LUP scheme to be assessed, from those driven by NPD-LUBC; (2) the prediction of NPD Land-use pattern simulated through the discrimination of NPD forces provides the basic data to support the LUPEA using our proposed methodology; (3) SO₂, PM₁₀, and COD emitted into the atmosphere and water are the major pollutants considered in the LUPEA of the city; and (4) despite the positive impacts of the comprehensive land-use change under the direction of target LUP, the implementation of LUP would have negative impacts on the regional environment in the entire study area and in individual counties/districts respectively in 2020. Our proposed methodology provides a new and operable way for the areas with data to simulate NPD land-use pattern and predict the individual indicator values for the assessment.