A Passive Flux Denuder for Evaluating Emissions of Ammonia at a Dairy Farm

Abstract

Passive samplers have been shown to be an inexpensive alternative to direct sampling. Diffusion denuders have been developed to measure the concentration of species such as ammonia (NH₃), which is in equilibrium with particulate ammonium nitrate. Conventional denuder sampling that inherently requires air pumps and, therefore, electrical power. To estimate emissions of NH₃ from a fugitive source would require an array of active samplers and meteorological measurements to estimate the flux. A recently developed fabric denuder was configured in an open tube to passively sample NH₃ flux. Passive and active samplers were collocated at a dairy farm at the California State University, Fresno, Agricultural Research Facility. During this comparison study, NH₃ flux measurements were made at the dairy farm lagoon before and after the lagoon underwent acidification. Comparisons were made of the flux measurements obtained directly from the passive flux denuder and those calculated from an active filter pack sampler and wind velocity. The results show significant correlation between the two methods, although a correction factor needed to be applied to directly compare the two techniques. This passive sampling approach significantly reduces the cost and complexity of sampling and has the potential to economically develop a larger inventory base for ambient NH₃ emissions.     

Correction to: Documenting lemming population change in the Arctic: Can we detect trends?

Ambio - In the original published article, some of the symbols in figure 1A were modified incorrectly during the typesetting and publication process. The correct version of the figure is provided...     

Socio-economic Impacts on Flooding: A 4000-Year History of the Yellow River, China

We analyze 4000-year flood history of the lower Yellow River and the history of agricultural development in the middle river by investigating historical writings and quantitative time series data of environmental changes in the river basin. Flood dynamics are characterized by positive feedback loops, critical thresholds of natural processes, and abrupt transitions caused by socio-economic factors. Technological and organizational innovations were dominant driving forces of the flood history. The popularization of iron plows and embankment of the lower river in the 4th century BC initiated a positive feedback loop on levee breaches. The strength of the feedback loop was enhanced by farming of coarse-sediment producing areas, steep hillslope cultivation, and a new river management paradigm, and finally pushed the flood frequency to its climax in the seventeenth century. The co-evolution of river dynamics and Chinese society is remarkable, especially farming and soil erosion in the middle river, and central authority and river management in the lower river.     

About plant species potentially promising for phytoextraction of large amounts of toxic trace elements

There is no information yet about plant species capable of accumulating many different metals/metalloids. The plants feasible for phytoremediation aims must grow fast, have high biomass, deep roots, and should accumulate and tolerate a range of toxicants in their aerial parts. In our research, greenhouse and field experiments have been performed to investigate accumulation and tolerance of not well-studied trace elements such as Br, Eu, Sc, Th (and also U) in couch grass and wheat. We compared bioaccumulation abilities of the plants with those of some other plant species grown under the same conditions. Additionally, we tested the effects of inoculation of seeds with Cellulomonas bacteria on phytoextraction of the trace elements from contaminated soils. For determination of elements, we used neutron activation analysis and ICP-MS. It was found that couch grass and wheat can grow in heavily contaminated soils and accumulate different toxic trace elements to levels that exceed physiological requirements typical for most plant species. Infection of seeds with bacteria resulted in a significant increase in the uptake of various trace elements and their translocation to upper plant parts. The use of couch grass and/or wheat, either alone or in combination with microorganisms, is a promising way to phytoextract metals/metalloids from contaminated soils.

     

Response of wheat and barley seedlings on soil contamination with bromides

Environmental Geochemistry and Health - Environmental pollution is becoming one of the most important global problems. Understanding the main factors affecting accumulation of toxic trace elements...     

A global empirical typology of anthropogenic drivers of environmental change in deltas

It is broadly recognized that river delta systems around the world are under threat from a range of anthropogenic activities. These activities occur at the local delta scale, at the regional river and watershed scale, and at the global scale. Tools are needed to support generalization of results from case studies in specific deltas. Here, we present a methodology for quantitatively constructing an empirical typology of anthropogenic change in global deltas. Utilizing a database of environmental change indicators, each associated with increased relative sea-level rise and coastal wetland loss, a clustering analysis of 48 global deltas provides a quantitative assessment of systems experiencing similar or dissimilar sources and degrees of anthropogenic stress. By identifying quantitatively similar systems, we hope to improve the transferability of scientific results across systems, and increase the effectiveness of delta management best practices. Both K-Means and Affinity Propagation clustering algorithms find similar clusters, with relative stability across small changes in K-Means cluster number. High-latitude deltas appear similar, in terms of anthropogenic environmental stress, to several low-population, low-latitude systems, including the Amazon delta, despite substantially different climatic regimes. Highly urbanized deltas in Southeast Asia form a distinct cluster. By providing a quantitative boundary between groups of delta systems, this approach may also be useful for assessing future delta change and sustainability given projected population growth, urbanization, and economic development trends.     

Geochemical and solute transport modelling for CO2 storage, what to expect from it?

Geochemistry plays an important role when assessing the impact of CO₂ storage. Due to the potential corrosive character of CO₂, it might affect the chemical and physical properties of the wells, the reservoir and its surroundings and increase the environmental and financial risk of CO₂ storage projects in deep geological structures. An overview of geochemical and solute transport modelling for CO₂ storage purposes is given, its data requirements and gaps are highlighted, and its progress over the last 10 years is discussed. Four different application domains are identified: long-term integrity modelling, injectivity modelling, well integrity modelling and experimental modelling and their current state of the art is discussed. One of the major gaps remaining is the lack of basic thermodynamical and kinetic data at relevant temperature and pressure conditions for each of these four application domains. Real challenges are the coupled solute transport and geomechanical modelling, the modelling of impurities in the CO₂ stream and pore-scale modelling applications.     

Management of waste electrical and electronic equipment in two EU countries: A comparison

The paper presents some data regarding waste electrical and electronic (WEEE) management in one of the founding countries of the EU, Italy, and in a recent entry into the EU, Romania. The aim of this research was to analyze some problems that countries entering the EU will have to solve with respect to WEEE management. The experiences of Italy and Romania could provide an interesting reference point. The strengths and weaknesses that the two EU countries have encountered can be used in order to give a more rational plan for other countries. In Italy the increase of WEEE collection was achieved in parallel with the increase of the efficiency of selective Municipal Solid Waste collection. In Romania, pilot experiences were useful to increase the awareness of the population. The different interests of the two populations towards recyclable waste led to a different scenario: in Romania all types of WEEE have been collected since its entrance into the EU; in Italy the “interest” in recycling is typically related to large household appliances, with a secondary role of lighting equipment.