Cement clinker: An environmental sink for residues from hazardous waste treatment in cement kilns

About 70% of all of the liquid and solid hazardous wastes commercially incinerated in the United States is being burned in cement kilns. The process inevitably results in residues, primarily heavy metals, entering the clinker and waste dusts (cement kiln dust, CKD) produced by these kilns. The effects of this trend on the nature and chemical composition of cement, actual and future, are discussed. The wastes burned by cement kilns are expected to increasingly have higher levels of heavy metals per Btu. In general, the effects are very simple to describe but have as yet unknown consequences. The present American Society for Testing and Materials (ASTM) standard does not effectively control hazardous waste burning residues in Portland Cement.The regulatory and economic pressures on CKD disposal suggest that much of it, and its heavy metal residues, will, in time, end up in the clinker and the resultant cement. The end point to the trend is the ability to make cement that passes the performance specifications while containing high levels of heavy metals. The only other alternative is to maximize the levels of heavy metals in the CKD, minimize the amount of CKD, and dispose of its as a hazardous waste.It is recommended that an effort to correlate heavy metal levels in clinker with adverse effects be undertaken, a new standard for cement containing hazardous and other waste residuals be developed, and labeling be required.     

HYDROLOGIC IMPACT OF WEATHER MODIFICATION1

ABSTRACT: Weather modification is being proposed as a routine method of augmenting agricultural water supplies in the Southern Great Plains. This paper discusses some of the potential hydrologic impacts of weather modification. Previous work in assessing hydrologic impact is covered; the conclusion is drawn that the work is insufficient. An approach based on hydrologic models is suggested that can consider uncertainties about the effect of weather modification on rainfall and some uncertainties about the effect of model error on impact conclusions.     

Forest Cover Change,Physiography, Local Economy,and Institutions in a Mountain Watershed in Nepal

This study assessed changes in forest cover in a mountain watershed in central Nepal between 1976 and 2000 by comparing classified satellite images coupled by GIS analyses, and examined the association of forest change with major physiographic, economic, and local forest governance parameters. The results showed an increase in forested area (forest plus shrublands) by 7.6% during 1976–2000. Forest dynamism (changes including improvement, deterioration, gain, and loss) was highest in low-elevation, south-facing and less-steep slopes that were closer to roads. Proportionately the highest net improvement and gain to forested area also took place in those locations. Forest degradation occurred at twice the rate of improvement in high elevation areas (> 2300 m). Forests located in urban and semiurban areas (i.e., a market-oriented economy) experienced a proportionately higher amount of net improvement and gain than forests in rural areas (i.e., a subsistence economy). Among the three governance arrangements, proportionately the highest net improvement and gain took place in semigovernment forests (forested area legally under the forest department but with de facto control and claim of ownership by local communities and/or municipality) followed by formalized community forests (including leasehold). Government forests, which were mostly found in the southern high mountains and had virtually open access, remained relatively stable during the study period. Over 50% of the watershed forests have not come under community-based management despite favorable policy and more than two decades of government intervention with continuous donor support. The findings indicate that the present one size fits all approach of community forest handover policy in Nepal needs rethinking to accommodate biophysical and socioeconomic variations across the country.     

Earthworm additions affect leachate production and nitrogen losses in typical midwestern agroecosystems

Earthworms affect soil structure and the movement of agrochemicals. Yet, there have been few field-scale studies that quantify the effect of earthworms on dissolved nitrogen fluxes in agroecosystems. We investigated the influence of semi-annual earthworm additions on leachate production and quality in different row crop agroecosystems. Chisel-till corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] rotation (CT) and ridge-till corn-soybean-wheat (Triticum aestivum L.) rotation (RT) plots were arranged in a complete randomized block design (n = 3) with earthworm treatments (addition and ambient) as subplots where zero-tension lysimeters were placed 45 cm below ground. We assessed earthworm populations semi-annually and collected leachate biweekly over a three-year period and determined leachate volume and concentrations of total inorganic nitrogen (TIN) and dissolved organic nitrogen (DON). Abundance of deep-burrowing earthworms was increased in addition treatments over ambient and for both agroecosystems. Leachate loss was similar among agroecosystems, but earthworm additions increased leachate production in the range of 4.5 to 45.2% above ambient in CT cropping. Although leachate TIN and DON concentrations were generally similar between agroecosystems or earthworm treatments, transport of TIN was significantly increased in addition treatments over ambient in CT cropping due to increased leachate volume. Losses of total nitrogen in leachate loadings were up to approximately 10% of agroecosystem N inputs. The coincidence of (i) soluble N production and availability and (ii) preferential leaching pathways formed by deep-burrowing earthworms thereby increased N losses from the CT agroecosystem at the 45-cm depth. Processing of N compounds and transport in soil water from RT cropping were more affected by management phase and largely independent of earthworm activity.     

Sydney tar ponds: some problems in quantifying toxic waste

Information on the type and amount of hazardous and toxic waste is required to develop a meaningful strategy and estimate a realistic cost for clean up of the Sydney Tar Pond site which is located on Cape Breton, in the province of Nova Scotia, Canada. The site covers the area of the decommissioned Sysco (Sydney Steel Corporation) plant. The materials of concern include BTEX (benzene, toluene, ethylbenzene, and xylenes), PAH (polycyclic aromatic hydrocarbons), PCB (polychlorinated biphenyl), and particulates laden with toxic metals, such as arsenic, lead, and others. The originally nontoxic materials such as soil, blast furnace slag, and vegetation, as well as surface and ground waters, which were subsequently contaminated, must also be included if they fail tests prescribed by environmental regulations. An extensive sampling program must be undertaken to obtain data for an accurate estimate of the waste to be cleaned and disposed of. Apparently, 700,000 tons of toxic waste, which is believed to be present on the site, may represent only a fraction of the actual amount. The clean-up of the site is only part of the solution. Toxic waste has to be disposed of in accordance with environmental regulations.     

Integrating social preference in GIS-aided planning for forestry and conservation activities: a case study from rural SE Asia

Land-use planning using geographic information systems (GIS) commonly emphasizes biophysical spatial data; however planning can be improved by integrating spatial sets of socioeconomic data into the GIS. As an example, we compared a traditional GIS-aided forestry planning protocol that considered only biophysical suitability, with an integrated GIS-aided approach that incorporated both biophysical and socioeconomic suitability. The analyses were conducted for the planning of plantation investments in the Kyaukpadaung Township in the dry zone of central Myanmar. The traditional approach used three biophysical layers for suitability: land use, slope, and accessibility. In contrast, the integrated GIS approach included biophysical suitability data, perceptions and preferences of local villagers towards forestry (social suitability), and quantitative socioeconomic data. The results indicated that the integrated approach provided two principal benefits over the traditional method. First, the integrated method resulted in a more precise idea of suitable sites for plantation investment that could benefit more rural people and also lead to greater investment efficiency. Second, incorporating social preference into the GIS takes into account the crucial element of social capital (viz., social preference), which should lead to higher levels of community acceptance of plantation projects because those plantations would be established on socially suitable land. A second GIS exercise showed how conservation investment decisions could be informed using the integrated method. The results of this study support the idea that GIS-aided planning activities can be enhanced through the incorporation of social data into the analysis. When applicable, spatial data collection efforts for GIS-based planning exercises should incorporate spatial socioeconomic data.     

Correlates of motivation for competitive or cooperative strategy among employed adults

The degree to which two measures of locus of control (LOC) and two measures of need for achievement (NACH) correlate with the motivations of persons for competitive or cooperative strategy was measured in 191 graduate students who are employed full-time as salaried employees. Results indicated significant correlations between motivation for competitive strategies and LOC, NACH, and the factors of LOC entitled self-confidence, internality, and belief in chance. The motivation to avoid the use of competitive strategies was correlated with belief in control by powerful others and chance. The motivation to use cooperative strategies failed to correlate significantly with either NACH or LOC.     

Restoring naturalness to national parks

National park resource management planning requires ecological information describing the objectives to be achieved. This information must be quantitative and unambiguous. Since most acts creating United States national parks, beginning with the Yellowstone National Park Act of 1872, specify that these parks should be maintained in a natural condition, resource management objectives for each national park must be defined in terms of quantitative standards of naturalness. Such quantitative standards of naturalness do not yet exist for any national park in the United States. Although this article focuses on US national parks, the same problem exists in national parks, reserves, and wilderness areas throughout the world. The physical evidence needed to develop quantitative standards of naturalness is rapidly disappearing because of the effects of management fires, wildfires, decomposition, successional changes, and other disturbances. Therefore, a nationwide rescue ecology program is recommended to recover as much remaining ecological information as possible before it is lost. This information is essential for developing quantitative standards to restore naturalness to national parks.