Competitive sorption and diffusion of chromate and sulphate in a flow system with goethite in gel beads

Column experiments and model simulations were employed to evaluate the processes involved in multicomponent solute transport in a system with heterogeneous flow. Column experiments were performed with goethite embedded in polyacrylamide gel beads. The gel forms an immobile water region that can be accessed by diffusion. A two-region transport model with diffusion into spheres was combined with a surface complexation model to predict reactive transport in the goethite-gel bead system. Chromate and sulphate breakthrough curves were measured in a set of transport experiments, along with corresponding changes in the pH of the effluent. Sorption and transport of sulphate and chromate in separate columns were predicted from independently measured sorption parameters. The model overestimated the pH changes in the effluent, possibly because of proton buffering by the polyacrylamide gel. The effect of competitive sorption on transport was examined in experiments with both anions present. The model predicted the effect of competition very well in a system initially equilibrated with sulphate, followed by infiltration with chromate. However, when sulphate was infiltrated after equilibration with chromate, chromate desorption and sulphate adsorption were clearly overestimated by the transport model. The exchange between the more strongly bound chromate and the sulphate added subsequently may be too slow to cause a substantial chromate peak in the effluent. This suggests that the local equilibrium assumption was not applicable in this case.     

A Methodology for an integrated risk assessment of spatially relevant hazards

Natural and technological disasters of the past have shown that such incidences significantly affect local and regional development. Faced with the task of ensuring economic, human and environmental development as well as insuring physical structures, planning authorities, insurance companies and emergency managers are looking for methodologies to identify highly sensitive areas in terms of their overall risk. Existing methodologies like the Natural Hazard Index for Megacities or the Total Place Vulnerability Index have limitations due to their sectoral approach, which makes them less useful for integrated spatial planning. This paper presents the Integrated Risk Assessment of Multi-Hazards as a new approach to serve as a basis for a spatial risk management process. The approach integrates various hazards into an integrated hazard map, combines this with the region's vulnerability and thus produces an integrated risk map. Moreover, the methodology offers a tool to derive weighting factors for hazards as well as for vulnerability components.     

Report: environmental assessment of Darmstadt (Germany) municipal waste incineration plant.

The focus of this study was the emissions from waste incineration plants using Darmstadt (Germany) waste incineration plant as an example. In the study the emissions generated by incineration of the waste were considered using three different approaches. Initially the emissions from the waste incineration plant were assessed as part of the impact of waste management systems on the environment by using a Municipal Solid Waste Management System (MSWMS) assessment tool (also called: LCA-IWM assessment tool). This was followed by a comparison between the optimal waste incineration process and the real situation. Finally a comparison was made between the emissions from the incineration plant and the emissions from a vehicle.     

Ethical Considerations in Agro-biodiversity Research,Collecting, and Use

Humans have always played a crucial role in the evolutionary dynamics of agricultural biodiversity and thus there is a strong relationship between these resources and human cultures. These agricultural resources have long been treated as a global public good, and constitute the livelihoods of millions of predominantly poor people. At the same time, agricultural biodiversity is under serious threat in many parts of the world despite extensive conservation efforts. Ethical considerations regarding the collecting, research, and use of agricultural biodiversity are currently topics of great concern. For example, easy access to genetic resources for breeding purposes is important, but international agreements and legal frameworks are necessary to ensure adequate recognition of the contributions of local communities and traditional farmers in creating and nurturing these resources. Here, we assess ethical principles in the context of existing codes of conduct that are relevant for agro-biodiversity researchers. We aim to create awareness among scientists and policy makers who are concerned with agro-biodiversity research and its potential impact on local communities. We encourage a serious assessment of the ethical principles presented here and hope to facilitate an integration of these principles into the reader’s personal ethical framework. Key ethical principles considered here include the importance of obtaining prior informed consent, equity, and the inalienability of rights of local communities and farmers.     

Chemical looping combustion for power generation—Concept study for a 10 MWth demonstration plant

A semi-commercial 10 MW_th chemical looping combustion (CLC) plant for power production is proposed as a next scale demonstration plant after successful operation of a 120 kW CLC pilot rig. The design criteria for the CLC boiler are derived from the experience obtained from the CLC pilot rig at Vienna University of Technology. The IPSEpro simulation environment is chosen for implementation of the process flow sheet of the CLC power plant. A single pressure steam cycle is suggested for this small scale demonstration plant. Heat exchangers and a five-stage steam turbine are arranged. Basic design parameters of the power plant are derived from detailed mass and energy investigations and discussed. It turns out that the net electric efficiency of such a small scale plant can be expected to be in the range of 32.5–35.8%. However, a demonstration of CLC at such a scale is necessary in order to gain confidence in more sophisticated CLC power generation concepts at larger scale.     

Modeling a Carbon Capture,Transport, and Storage Infrastructure for Europe

In this paper, we develop a model to analyze the economics of carbon capture, transport, and storage (CCTS) in the wake of expected rising CO₂ prices. We present a scalable mixed integer, multiperiod, welfare-optimizing network model for Europe, called CCTS-Mod. The model incorporates endogenous decisions on carbon capture, pipeline and storage investments, as well as capture, flow and injection quantities based on given costs, CO₂ prices, storage capacities, and point source emissions. Given full information about future costs of CCTS-technology, and CO₂ prices, the model determines a cost minimizing strategy on whether to purchase CO₂ certificates, or to abate the CO₂ through investments into a CCTS-chain on a site by site basis. We apply the model to analyze different scenarios for the deployment of CCTS in Europe, e.g., under high and low CO₂ prices, respectively. We find that beyond CO₂ prices of €50 per t, CCTS can contribute to the decarbonization of Europe’s industry sectors, as long as one assumes sufficient storage capacities (onshore and/or offshore). We find that CCTS is only viable for the power sector if the CO₂ certificate price exceeds €75 per t.