Assessment of Use,Reuse, and End‐of‐Life Disposal and X‐Ray Fluorescence Analysis Screening of Waste Mobile Phones in Nigeria

Insights into consumer behavior, hazards of inappropriate disposal, and opportunities to reclaim valuable resources     

The Effects of Changing Land Cover on Streamflow Simulation in Puerto Rico

This study quantitatively explores whether land cover changes have a substantive impact on simulated streamflow within the tropical island setting of Puerto Rico. The Precipitation Runoff Modeling System (PRMS) was used to compare streamflow simulations based on five static parameterizations of land cover with those based on dynamically varying parameters derived from four land cover scenes for the period 1953‐2012. The PRMS simulations based on static land cover illustrated consistent differences in simulated streamflow across the island. It was determined that the scale of the analysis makes a difference: large regions with localized areas that have undergone dramatic land cover change may show negligible difference in total streamflow, but streamflow simulations using dynamic land cover parameters for a highly altered subwatershed clearly demonstrate the effects of changing land cover on simulated streamflow. Incorporating dynamic parameterization in these highly altered watersheds can reduce the predictive uncertainty in simulations of streamflow using PRMS. Hydrologic models that do not consider the projected changes in land cover may be inadequate for water resource management planning for future conditions.     

Assessment and review of organochlorine pesticide pollution in Kyrgyzstan

The current study describes the preliminary assessment and securing activities of the largest and most hazardous POPs-contaminated sites in Kyrgyzstan. In 2010, cattle died and population were found with high pesticide levels in blood, human milk, and placenta. In the first phase of the study, a historic assessment of the pesticide dumping at the landfill/dump sites have been conducted. In the second phase, soil analysis for organochlorine pesticides in the areas of the pesticide disposal sites, the former pesticides storehouses, agro-air strips, and the cotton-growing fields were conducted. By this assessment, a first overview of the types and sources of pollution and of the scale of the problem is compiled including information gaps. From major pesticides used, DDT, DDE, and HCH were measured in the highest concentrations. With the limited analytical capacity present, a reasonable risk assessment could be performed. This paper also reports on practical risk reduction measures that have been carried out recently at the two major pesticide disposal sites with support of a Dutch environmental engineering company, an international NGO (Green Cross Switzerland) and local authorities from the Suzak region within an UN project. Local population living near the sites of the former pesticide storehouses and agro-airstrips are advised not to cultivate vegetables and melons or to raise cattle on these areas. Instead, it is recommended to grow technical crops or plant trees. Further recommendations on monitoring and assessment is given including the suggestion to consider the findings in the National Implementation Plan of Kyrgyzstan.     

Evaluation of numerical simulations of CO2 transport in a city block with field measurements

Studying urban air-transport phenomena is highly complex, because of the heterogenous flow patterns that can arise. The main reason for these is the variable topology of urban areas, however, there is a large number of influencing variables such as meteorological conditions (e.g., wind situation, temperature) and anthropogenic factors such as traffic emissions. During a one-year CO₂ measurement campaign in the city of Basel, Switzerland, steep CO₂ gradients were measured around a large building. The concentration differences showed a strong dependency on the local flow regimes. Analysis of the field data alone did not provide a complete explanation for the mechanisms underlying the observed phenomena. The key numerical parameters were defined and the influence of turbulent kinetic energy dependency on the time interval for the Reynolds decomposition was studied. A Reynolds-Average Navier-Stokes Computational Fluid Dynamics (CFD) approach was applied in the study area and the CO₂ concentrations were simulated for six significant meteorological situations and compared to the measured data. Two flow regimes dependent on the wind situation, which either enhanced or suppressed the concentration of CO₂ in the street canyon, were identified. The enhancement of CO₂ in the street canyon led to a large difference in CO₂ concentration between the backyard- and street-sides of a building forming the one wall of the canyon. The specific characteristics of the flow patterns led to the identification of the processes determining the observed differences in CO₂ concentrations. The combined analysis of measurement and modeling showed the importance of reliable field measurements and CFD simulations with a high spatial resolution to assess transport mechanisms in urban areas.     

?kotoxikologie soll endlich wissenschaftliches Fach werden

Ohne Zusammenfassung     

Bioethics of fish production: Energy and the environment

Aquatic ecosystems are vital to the structure and function of all environments on earth. Worldwide, approximately 95 million metric tons of fishery products are harvested from marine and freshwater habitats. A major problem in fisheries around the world is the bioethics of overfishing. A wide range of management techniques exists for fishery, managers and policy-makers to improve fishery production in the future. The best approach to limit overfishing is to have an effective, federally regulated fishery, based on environmental standards and fishery carrying capacity. Soon, overfishing is more likely to cause fish scarcity than fossil fuel shortages and high energy prices for fish harvesting. However, oil and other fuel shortages are projected to influence future fishery policies and the productive capacity of the fishery industry. Overall, small-scale fishing systems are more energy efficient than large-scale systems. Aquaculture is not the solution to wild fishery production. The energy input/output ratio of aquacultural fish is much higher than that of the harvest of wild populations. In addition, the energy ratios for aquaculture systems are higher than those for most livestock systems.     

HYDRAULIC FRICTION LOSS IN SMALL DIAMETER PLASTIC PIPELINES1

ABSTRACT: Although estimation of hydraulic friction loss in pipelines is one of the most frequent routine computations made by water supply engineers, almost no post-construction analysis of the accuracy of these calculations exists in the literature. This paper reports the field measured friction losses in three one-mile sections of small diameter pvc pipe which had been in service for 10 years. Hazen-Williams and Darcy-Weisbach equations are examined to provide a framework for comparing Hazen-Williams coefficients recommended by pipe manufacturers to those obtained by the field measurements. The conclusion is that the C_HW factor of 150 recommended by most pvc pipe manufacturers is too high for the diameter-velocity combinations encountered in rural dead-end small diameter lines. The measured coefficients averaged 133 which is close to that predicted by superimposing Hazen Williams coefficients on the Moody diagram from which the friction factor for the Darcy-Weisbach equation is obtained.     

Relevance of BFRs and thermal conditions on the formation pathways of brominated and brominated-chlorinated dibenzodioxins and dibenzofurans

The widespread use of brominated flame-retarded products in the last two decades has resulted in an increasing presence of bromine in thermal processes such as waste combustion and accidental fires. Brominated and brominated-chlorinated dibenzodioxins and dibenzofurans (PBDDs/PBDFs, PXDDs/PXDFs) are micropollutants of concern arising from such processes. The present review aims to evaluate the relevance of these compound classes in actual thermal processes. Four categories of thermal processes are discussed in this respect according to their potential for PBDD/PBDF and PXDD/PXDF generation: thermal stress, pyrolysis/gasification, insufficient combustion conditions and controlled combustion conditions. Under thermal stress situations, as they may occur in production or recycling processes, PBDDs/PBDFs precursors like polybrominated diphenylethers (PBDE) can have a relevant potential for PBDD/PBDF formation via a simple elimination. Under insufficient combustion conditions as they are present in, e.g. accidental fires and uncontrolled burning as well as gasification/pyrolysis processes, considerable amounts of PBDDs/PBDFs can be formed from BFRs, preferably via the precursor pathway. In contrast, under controlled combustion conditions, BFRs and PBDDs/PBDFs can be destroyed with high efficiency. The relevance of de novo synthesis of PXDDs/PXDFs is discussed for this condition.Providing a basis for the understanding of PXDD/PXDF formation in actual thermal processes, the present paper also summarises the formation pathways of brominated and brominated-chlorinated PXDDs/PXDFs from brominated flame retardants (BFRs) investigated during laboratory thermolysis experiments. Relevant mechanistic steps for PBDD/PBDF formation from brominated precursors are discussed including elimination reactions, condensation steps and debromination/hydrogenation reactions.In addition, chlorination/bromination and halogen exchange reactions are briefly discussed with respect for their relevance on the final distribution of PBDDs/PBDFs, mixed chlorinated PXDDs/PXDFs and PCDDs/PCDFs resulting from thermal processes.     

Assessment of the Ecological Integrity of Traunsee (Austria) Via Analysis of Sediments and Benthic Microbial Communities

Since nearly one hundred years Traunsee experiences the import of tons of liquid and solid waste originating from salt and soda production. Today, the lake exhibits chloride concentrations of up to 170 mg L^-1 and 19% of the lake floor are directly or indirectly influenced by industrial deposits (ID). Based on the comparison of several microbial parameters in unaffected, directly affected and intermediate lake bottom sediments, the ecological integrity of the lake was evaluated. The highly alkaline ID, which were exclusively colonized by microorganisms, harbored a bacterial community reduced by a factor of 10 in abundance and biomass compared to undisturbed sediment areas within the lake. The bacterial community of ID was furthermore characterized by a reduced content of actively respiring cells (INT-formazan reduction), a lower frequency of dividing cells (FDC) and a significantly reduced cell and biomass production. A 80 to 90% reduction in carbon recycling is estimated for the area exclusively covered by ID. Protists, although occasionally absent from the industrial sediments, were in general found to be less sensitive to the contaminant stress. Differences in alkalinity and dissolved organic carbon (DOC) concentrations of sediment porewaters as well as the total organic content and C/N ratios of sediments partly explain the microbial pattern observed at the various sampling sites. Possible consequences of the continuous industrial tailings for the whole lake ecosystem and the validation of the ecological integrity are discussed.