A New Approach of BioCO2 Fixation by Thermoplastic Processing of Microalgae

Effective sequestration of carbon dioxide (CO₂) by algae reduces greenhouse gases effect on global warming. Algae biomass or residual such as biomeal from algae biofuel processing can be judiciously used for industrial applications such as fertilizer, animal feed, and plastics. Conversion of algae into useful plastic materials can be accomplished by extrusion technology. During algal plastic manufacturing, up to 20% thermoplastic algal blends can be fixated into or encapsulated by a non-biodegradable polymer such as polyolefin, which is known to be resistant to abiotic or biotic degradation. As a result, CO₂ that is captured by algae through photosynthesis is permanently stored in a form of biomass and will not be released back into the atmosphere. The extrusion of microalgae reported in this article is a novel process to sequester CO₂ and at the same time it makes a good use of the algae biomass in plastic manufacturing. Mechanical properties of the thin plastic films containing microalgae are comparable to the neat polyurethane or polyethylene films. Injection molded articles containing microalgae are dimensionally stable. However, a lower tensile strength, especially elongation at break, is observed in comparison to the neat polypropylene.     

CHARGES FOR URBAN RUNOFF: ISSUES IN IMPLEMENTATION1

ABSTRACT: Maryland officials have identified stormwater utilities as a potential method of financing programs to control nutrients in urban stormwater runoff that are proposed in Maryland's Chesapeake Bay Nutrient Reduction Plan. This paper reviews a number of issues related to the equity, efficiency and acceptability of user charge schemes. Overall, charges are found to be preferable to property taxes from both equity and efficiency perspectives. In addition, evidence suggests that elected officials will support creation of utilities. Obstacles to the implementation of utilities are identified.     

Tourist Support for Marine Protection in Nha Trang,Viet Nam

Environmental planners often propose tourism as a means of financing programmes to protect significant environmental areas. Surveys of tourists can provide useful information about the significance of environmental problems, trade-offs among policy objectives, willingness to pay (WTP) for protection programmes and preferences for different payment mechanisms. In Khanh Hoa Province, the provincial People's Committee, the Ministry of Fisheries and the World Conservation Union are working to implement Viet Nam's first marine protected area (MPA) in Nha Trang Bay. This paper reports the results of a survey of local and other Vietnamese and foreign tourists to islands that will be included in the MPA. The majority of respondents thought rubbish on the beaches, water pollution and vendors on beaches were problems and that the MPA was a good idea. Foreign tourists were significantly more likely to perceive environmental problems than were Vietnamese tourists, and persons who agreed there were environmental problems were significantly more likely to support the concept of an MPA, despite the potential for possible economic effects with distributive consequences. WTP for protection was modest and positively correlated with education and income. Although foreign tourists were on average willing to pay more, a larger proportion of Vietnamese tourists were willing to pay some amount to support the MPA. Analyses indicate that changes in income and education expected with economic development will increase both awareness of problems and WTP for protection. The results of this analysis are both encouraging and cautionary. The need for an MPA is clearly recognized by most tourists, and most tourists are willing to pay small fees to support the MPA. Given that education has significant impacts on both perceptions of problems and WTP, educational programmes may be an effective strategy for managing the competing objectives of protection and use.     

Appropriate water supply and sanitation technology for developing countries in tropical monsoon climates

Summary In the past, the water supply and sewage services for the urban regions of developing countries have been provided, in the main, only for the more affluent areas of these cities. This paper, dealing especially with those countries with tropical monsoon climates, advocates the construction of more comprehensive systems.Experience drawn from a wide range of projects and a review of the relevant literature provokes the authors to emphasise the need for suitable manuals of appropriate technology for use in these developing countries. These manuals should provide a full set of environmental guidelines for the design of water supply and sewage/sanitation systems for use in these countries.Dr Harvey F. Ludwig is Chairman and Greg Browder is Environmental Engineer for SEATEC International Consulting Engineers, Bangkok, Thailand.     

An evaluation of public participation information for land use decisions: public comment,surveys, and participatory mapping

ABSTRACT

Public participation in the form of public meetings and written submissions has been criticised as a democratic ritual that fails to give citizens a real voice in government decisions. Participatory mapping and community surveys are alternative public participation (PP) methods that can augment legally required processes for land use planning. To date, there has been little evaluation research comparing the information content generated by required PP processes and alternative PP sources with respect to local land use decisions. Using multiple development projects from a case study community, we analysed and compared information generated from three different sources of public participation: (1) formal public comment (written submissions), (2) responses to community survey questions, and (3) land use preferences generated from participatory mapping. We found public comment strongly supported development while results from survey questions and participatory mapping methods revealed community ambivalence. The differences in public opinion are attributed to two key factors: the representativeness of participants in the PP process and the specific methods used for measuring public opinion. Community surveys and participatory mapping generated more accurate and representative community information compared to the formal PP process which was characterised by lower participation and vulnerability to special interest manipulation. For local government decision makers, the political risk of broadening PP information appears high relative to the risk of inaccurately assessing public opinion thus limiting adoption of alternative PP methods such as participatory mapping.     

Spatiotemporal Associations of Reservoir Nutrient Characteristics and the Invasive,Harmful Alga Prymnesium parvum in West Texas

Golden alga (Prymnesium parvum) is a harmful alga that has caused ecological and economic harm in freshwater and marine systems worldwide. In inland systems of North America, toxic blooms have nearly eliminated fish populations in some systems. Modifying nutrient profiles through alterations to land or water use may be a viable alternative for golden alga control in reservoirs. The main objective of this study was to improve our understanding of the nutrient dynamics that influence golden alga bloom formation and toxicity in west Texas reservoirs. We examined eight sites in the Upper Colorado River basin, Texas: three impacted reservoirs that have experienced repeated golden alga blooms; two reference reservoirs where golden alga is present but nontoxic; and three confluence sites downstream of the impacted and reference sites. Total, inorganic, and organic nitrogen and phosphorus and their ratios were quantified monthly along with golden alga abundance and ichthyotoxicity between December 2010 and July 2011. Blooms persisted for several months at the impacted sites, which were characterized by high organic nitrogen and low inorganic nitrogen. At impacted sites, abundance was positively associated with inorganic phosphorus and bloom termination coincided with increases in inorganic nitrogen and decreases in inorganic phosphorus in late spring. Management of both inorganic and organic forms of nutrients may create conditions in reservoirs unfavorable to golden alga.     

Calibrating a Basin‐Scale Groundwater Model to Remotely Sensed Estimates of Groundwater Evapotranspiration

Remotely sensed vegetation indices correspond to canopy vigor and cover and have been successfully used to estimate groundwater evapotranspiration (ET_g) over large spatial and temporal scales. However, these data do not provide information on depth to groundwater (dtgw) necessary for groundwater models (GWM) to calculate ET_g. An iterative approach is provided that calibrates GWM to ET_g derived from Landsat estimates of the Enhanced Vegetation Index (EVI). The approach is applied to different vegetation groups in Mason Valley, Nevada over an 11‐year time span. An uncertainty analysis is done to estimate the resulting mean and 90% confidence intervals in ET_g to dtgw relationships to quantify errors associated with plant physiologic complexity, species variability, and parameter smoothing to the 100 m GWM‐grid, temporal variability in soil moisture and nonuniqueness in the solution. Additionally, a first‐order second moment analysis shows ET_g to dtgw relationships are almost exclusively sensitive to estimated land surface, or maximum, ET_g despite relatively large uncertainty in extinction depths and hydraulic conductivity. The EVI method of estimating ET_g appears to bias ET_g during years with exceptionally wet spring/summer conditions. Excluding these years improves model performance significantly but highlights the need to develop a methodology that accounts not only on quantity but timing of annual precipitation on phreatophyte greenness.