Strontium isotope study of coal utilization by-products interacting with environmental waters

Sequential leaching experiments on coal utilization by-products (CUB) were coupled with chemical and strontium (Sr) isotopic analyses to better understand the influence of coal type and combustion processes on CUB properties and the release of elements during interaction with environmental waters during disposal. Class C fly ash tended to release the highest quantity of minor and trace elements-including alkaline earth elements, sodium, chromium, copper, manganese, lead, titanium, and zinc-during sequential extraction, with bottom ash yielding the lowest. Strontium isotope ratios ((87)Sr/(86)Sr) in bulk-CUB samples (total dissolution of CUB) are generally higher in class F ash than in class C ash. Bulk-CUB ratios appear to be controlled by the geologic source of the mineral matter in the feed coal, and by Sr added during desulfurization treatments. Leachates of the CUB generally have Sr isotope ratios that are different than the bulk value, demonstrating that Sr was not isotopically homogenized during combustion. Variations in the Sr isotopic composition of CUB leachates were correlated with mobility of several major and trace elements; the data suggest that arsenic and lead are held in phases that contain the more radiogenic (high-(87)Sr/(86)Sr) component. A changing Sr isotope ratio of CUB-interacting waters in a disposal environment could forecast the release of certain strongly bound elements of environmental concern. This study lays the groundwork for the application of Sr isotopes as an environmental tracer for CUB-water interaction.     

Park isolation in anthropogenic landscapes: land change and livelihoods at park boundaries in the African Albertine Rift

Regional Environmental Change - Landscapes are changing rapidly in regions where rural people live adjacent to protected parks and reserves. This is the case in highland East Africa, where many...     

Drivers of social equity in renewable energy at the municipal level: the case of local Japanese energy policy and preferences

ABSTRACT

Recent research has allowed us to quantify the costs and benefits of adopting renewable energy in specific municipalities, but how do these outcomes vary among communities at the national scale? This study uses survey responses from 47 Japanese municipalities to model these impacts and identifies key technological, social, and demographic factors that shape which communities benefit more from the renewable energy transition. On average, introducing renewable energy improves social equity, any financial burden on electricity prices is born most by wealthier residents, not the poor, and towns are predisposed to benefit from renewables no matter the amount introduced. To improve these impacts, towns can increase the amount of solar they host, or they can adjust the amount of CO2 emissions, PM emissions, tax revenue, jobs gained, or unpopular renewable power plants in their town. However, preferences and demographics matter as well. Age, education, and local preferences in favor of employment and community development all significantly relate to equity potential outcomes. Policymakers should consider adjusting their local energy priorities using these levers if they hope to engineer a renewable energy transition that is both positive and popular for their constituents.     

Use of Australian cladocerans to generate life-cycle toxicity data

Cladocerans (or water-fleas) are important animals in freshwater exosystems. They are widely used in toxicity tests because of their small size, ease of culture, and sensitivity to chemicals. They are particularly suited to life-cycle tests because newly-hatched young can produce offspring in less than one week. Most data are available for European and North American species, and may be not be appropriate to Australian conditions. In the present study, eight Australian cladocerans were evaluated in three-brood life-cycle tests over ten days or less. Species were evaluated by duration of life cycle, ease of handling, numbers of young produced in three broods, and stability in laboratory culture.Ceriodaphnia cfdubia was the best test species. The greatest number of young, the highest survival rate and the shortest time to produce three broods were achieved in filtered Sydney mains water, aged in the presence of fish, using blended trout pellets and alfalfa as food.     

Discharge of oilfield-produced water in nueces bay,texas: A case study

During oil and gas production, water is often extracted from geological formations along with the hydrocarbons. These "produced waters" have been discharged to Nueces Bay since the turn of the century. These effluents were found to be highly toxic, and sediments in the vicinity of the discharges were also toxic. We developed a map of wells and produced-water discharge sites in the vicinity of Nueces Bay and identified numerous unplugged wells suitable for conversion to produced water disposal wells. An economic analysis of conversion to subterranean injection of produced water indicates that most of the wells currently in production could pay out the cost of conversion to injection in one to three years. The use of one injection well for two or more water-producing wells could yield greater savings. Wells that could not support the cost of injection are small producers, and their loss would not constitute a major loss of jobs or dollars to the area. This study could serve as a useful model for evaluating the economic feasibility of conversion to injection in other areas of Texas and Louisiana.     

空气污染对儿童及其父母呼吸系统健康的影响

 根据空气污染数据对广州、武汉、兰州、重庆4城市8个点位进行了空气污染的聚类分析,并按空气污染程度进行了排序.在此基础上,分析了空气污染程度与儿童及其父母呼吸系统健康的关系.发现儿童11种患病率随空气污染程度加重而呈上升趋势.污染最重组的患病率是污染较轻组的1.71(3.95倍.污染最重组的比数比(即OR值)是污染较轻组的3.313(6.942倍.空气污染对儿童父母的呼吸系统患病率也有轻度至中度的影响.     

Ecotypic differentiation of Laminaria longicruris in relation to seawater nitrate concentration

The ultraplankton (cell diameters >3 μm), which compromises about 70% of the biomass of phytoplankton in subtropical surface waters near Oahu, Hawaii, was isolated for growth rate studies. The specific growth rate (μ) was estimated from the rate of increase of the chlorophyll biomass during incubations in the absence of grazers. This growth rate of the ultraplankton ranged from 0.037 to 0.071 h^?1 (=1.3 to 2.5 doublings d^?1) during a period when P:B ratios of 5 to 14.5 μg C μg^?1 chl a h^?1 prevailed. The co-occurrence of atypically high P:B ratios and nonlimiting ambient nutrient concentrations suggests that the calculated values are higher than those characteristic of such subtropical ecosystems in general. Rates of ammonium uptake and photosynthesis by the >3 μm fraction were also compared to those of larger fractions. Organisms in the >3 μm fraction assimilated NH ₄ ⁺ at a rate which was about 75% greater than that of the 3 to 20 μm size fraction. Comparison of μ and P:B data collected over a 2 mo period (November–December, 1980) shows that the correlation between these two rate indices is nonlinear. The predominance of small-celled phytoplankton in oligotrophic waters is explained, in part, by its higher μ, its higher nutrient assimilation rates, and the absence of its loss through sedimentation.