CO2 capture from pre-combustion processes—Strategies for membrane gas separation

The application of membrane gas separation to CO₂ capture from a coal gasification process is one potential solution to reduce greenhouse gas emissions. This review considers the potential for either H₂- or CO₂-selective membranes in an integrated gasification combined cycle (IGCC) process. In particular, the advantages and disadvantages of metallic, porous inorganic and polymeric membranes are considered. This analysis is extended to consider membrane technology as an enhancement to the water-gas shift reaction, to drive the production of hydrogen above the thermodynamic limit. The review concludes with a brief overview of the economics of incorporating membrane gas separation into the IGCC process and gives an indication of the potential economic use of membrane gas separation technology in the IGCC process.     

Regionalizing potential for microbial bypass flow through New Zealand soils

Microbial breakthrough curves of 12 soils, generated by the application of dairy shed effluent followed by continuous artificial rainfall for one pore volume at 5 mm h(-1) onto large undisturbed soil cores, have been ranked as high, medium, or low potential for microbial bypass flow. The ranking is based on the position of the peak in the breakthrough curve. Knowledge of soil properties that affect microbial transport through soil gained from the microbial breakthrough curves was linked to soil classes, or to their accessory properties, of the New Zealand Soil Classification. Spatial depiction of the ratings has been achieved via the national 1:50,000 scale soil map. Soils with a drainage impediment or those with well developed soil structure have a high potential for microbial bypass flow, whereas soils from tephra and Recent Soils with less developed, porous, soil structure have a low potential for microbial bypass flow. The risk rankings should be considered as maxima because management may change some rankings.     

Use of GIS in siting stabilization pond facilities for domestic wastewater treatment

Geographic information systems (GIS) use is presented in the problem of sitting areas for construction of natural systems such as stabilization ponds (SPs) for domestic wastewater treatment. For this purpose, several variables, such as topography, land use, type of geological formation, distance to major rivers or lakes, distance to existing cities and villages, existence of environmentally protected areas, mean minimum monthly temperatures and required wastewater effluent characteristics were analyzed with the GIS, in order to accept or reject a particular area within a region. The method is applied in the region of Thrace (Northeast Greece) at the municipal level. The required area for SP systems was calculated in each of the 36 municipalities of Thrace (including two islands, Thassos and Samothraki) as a function of the population of each municipality, temperature and local wastewater effluent discharge criteria. Based on the GIS analysis, suitable locations were identified in each municipality first, and then the total required surface area of these systems was compared to the available surface area of each municipality, in order to decide whether SP systems could be a viable solution to the wastewater management problem in the particular region. In that way the present methodology offers a fast and simple method to check the suitability of new areas for construction of such systems.     

Public Participation in Local Government Review of Development Proposals in Hazardous Locations: Does it Matter, and What Do Local Government Planners Have to Do with It?

Natural hazard investigators recommend that local governments adopt mitigation plans to help reduce hazard losses. However, such plans are unlikely to be effective unless a wide range of public stakeholders is involved in their creation. Previous research shows that stakeholder participation levels in hazard mitigation planning tend to be low, though there may be particular choices that local government planners can make to foster participation. We examine the importance of planners’ choices and role orientations (i.e., beliefs regarding appropriate behavior in the workplace) for participation levels in site plan review, wherein local governments review site plans for proposed development projects to ensure compliance between project design and applicable plans and policies. Using a national sample of 65 development projects located in areas subject to natural hazards, and bivariate and multivariate analyses, we examine whether participation levels during site plan review depend upon planners’ choices and role orientations, and whether participation levels are correlated with the incorporation of hazard mitigation techniques into development projects. We find significant correlations between participation levels and planners’ choices, between participation levels and planner’s role orientations, and between participation levels and the incorporation of hazard mitigation techniques. We encourage local government planners to revisit their beliefs, choices, and behaviors regarding public participation in site plan review.