Leaching of metals from fly ashes in the presence of complexing agents

The leachability of some metals (Al, As, Ba, Ca, Cr, Cu, Fe, K, Mg, Mn, Ti, Zn) from fly ashes was studied in the presence of ethylenediamine tetraacetic acid (EDTA) and naturally occurring complexing agents-humic acids (HAs). Secondary complex-forming equilibria taking place in the leachates increase significantly the leached amounts of most metals. Kinetic experiments showed that almost the whole "available" amounts of metals are leached from fly ash within a time period of several hours (mostly within 20 h), with exceptions of matrix constituents (typically aluminium), which are released more slowly.     

Monitoring household waste recycling centres performance using mean bin weight analyses

This paper describes a modelling approach used to investigate the significance of key factors (vehicle type, compaction type, site design, temporal effects) in influencing the variability in observed nett amenity bin weights produced by household waste recycling centres (HWRCs). This new method can help to quickly identify sites that are producing significantly lighter bins, enabling detailed back-end analyses to be efficiently targeted and best practice in HWRC operation identified. Tested on weigh ticket data from nine HWRCs across West Sussex, UK, the model suggests that compaction technique, vehicle type, month and site design explained 76% of the variability in the observed nett amenity weights. For each factor, a weighting coefficient was calculated to generate a predicted nett weight for each bin transaction and three sites were subsequently identified as having similar characteristics but returned significantly different mean nett bin weights. Waste and site audits were then conducted at the three sites to try and determine the possible sources of the remaining variability. Significant differences were identified in the proportions of contained waste (bagged), wood, and dry recyclables entering the amenity waste stream, particularly at one site where significantly less contaminated waste and dry recyclables were observed.     

Use of Performance Models in Restoration Projects

Environmental restoration projects can benefit from using performance models tied to monitoring plans and closure/exit strategies. Theoretical aspects are discussed and a case study is provided to illustrate how models can be developed and applied. Recognizing that site characterization cannot remove all uncertainty, most performance models cannot be narrowly developed (e.g., specific concentrations expected over time). Instead they must define threshold values at which performance data indicate the remedy is failing, or at least is not operating at the required level to achieve objectives within a reasonable timeframe. Ultimately, the performance model should be transformed to a closure model. The closure model is intended to document how closure was achieved and what measures remain in place to ensure protection of human health and the environment. In this context, the performance model is an intermediate step in the sequence starting from a conceptual site model and ending as the closure model. © 2014 Wiley Periodicals, Inc.     

Genital shape correlates with sperm transfer success in the praying mantis Ciulfina klassi (Insecta: Mantodea)

The rapid divergence of male genitalia is a widely observed evolutionary phenomenon. Although sexual selection is currently regarded as providing the most likely driving force behind genital diversification, the mechanisms responsible are still debated. Here, we investigate the relationship between male genital morphology and sperm transfer in the praying mantid Ciulfina klassi using geometric morphometrics. The shape of male genitalia in C. klassi influenced sperm transfer duration and the number and proportion of sperm transferred, suggesting that genital morphology is under sexual selection in this species. Genital size however was not correlated with any aspect of sperm transfer. Intriguingly, two of the major genital shape components correlated positively with the number of sperm transferred, but negatively with sperm transfer duration. Hence, males that most effectively transfer sperm to the female spermatheca do so in a relatively short period of time. A direct negative relationship was also found between sperm transfer duration and sperm transfer success. Overall, our study suggests that the variable genital shape of Ciulfina may have been selected for more efficient sperm transfer.     

Bird conservation and the land sharing-sparing continuum in farmland-dominated landscapes of lowland England

Empirical evidence from many regions suggests that most species would be least negatively affected if human food demand were met through high-yield agricultural production and conservation of nonfarm ecosystems (land sparing), rather than through wildlife-friendly farming over a larger area (land sharing). However, repeated glaciation and a long history of agriculture may lead to different results in regions such as western Europe. We compared the consequences of land sparing and land sharing on breeding bird species in 2 lowland regions of England, The Fens, with 101 species, and Salisbury Plain, with 83. We derived density–yield responses for each species and then estimated regional population size under regional food production strategies, including land sharing and land sparing, a range of intermediate strategies, and a novel mixed strategy. In both regions, more species achieved maximum regional population size under land sparing than land sharing. In The Fens, the majority of birds were loser species (estimated to have smaller populations under all food production strategies than in the preagricultural baseline scenario), whereas in Salisbury Plain the majority were winners (smaller populations in the preagricultural baseline scenario). Loser species overwhelmingly achieved maximum regional population size under land sparing, whereas winner species achieved maximum regional population size under either land sharing or an intermediate strategy, highlighting the importance of defining which groups of species are the target of conservation. A novel 3-compartment strategy (combining high-yield farming, natural habitat, and low-yield farming) often performed better than either land sharing or land sparing. Our results support intermediate or 3-compartment land-sparing strategies to maximize bird populations across lowland agricultural landscapes. To deliver conservation outcomes, any shift toward land sparing must, however, ensure yield increases are sustainable in the long term, do not entail increased negative effects on surrounding areas, and are linked to allocation of land for nature.     

Estimation of pollutant partition in sandy soils with different water contents

The objectives of this work were: (1) to identify an isotherm model to relate the contaminant contents in the gas phase with those in the solid and non-aqueous liquid phases; (2) to develop a methodology for the estimation of the contaminant distribution in the different phases of the soil; and (3) to evaluate the influence of soil water content on the contaminant distribution in soil. For sandy soils with negligible contents of clay and natural organic matter, contaminated with benzene, toluene, ethylbenzene, xylene, trichloroethylene (TCE), and perchloroethylene (PCE), it was concluded that: (1) Freundlich’s model showed to be adequate to relate the contaminant contents in the gas phase with those in the solid and non-aqueous liquid phases; (2) the distribution of the contaminants in the different phases present in the soil could be estimated with differences lower than 10% for 83% of the cases; and (3) an increase of the soil water content led to a decrease of the amount of contaminant in the solid and non-aqueous liquid phases, increasing the amount in the other phases.     

Contamination of wild-grown edible mushrooms by heavy metals in a former mercury-mining area

The aim of this study was to evaluate the contamination of six edible wild species of mushrooms (Boletus pulverulentus, Cantharellus cibarius, Lactarius quietus, Macrolepiota procera, Russula xerampelina and Suillus grevillei) by heavy metals (Hg, Cd, Pb, Zn, Cu, Ni, Cr, Co, Mn and Fe). Mushroom samples were collected from sites contaminated by emissions from mining and processing of polymetallic ores in operation during the period 1969–1993 in Rudňany, southeast Slovakia. The four study sites spanned up to a 5-km distance from the emission source. The collected mushroom samples were analyzed using Flame Atomic Absorption Spectrophotometry and/or Flame Atomic Absorption Spectrophotometry with graphite furnace. Mercury, Cd and, in some samples, also Pb present the highest risks in terms of contamination of the food chain following subsequent consumption. The content of two metals in the dry matter (dm) of the mushrooms exceeded the limits set by the European Union (EU; Cd: 0.5 mg/kg dm, Pb: 1.0 mg/kg dm). The highest mean contents of the eight metals recorded for S. grevillei were 52.2, 2.15, 107, 104, 2.27, 2.49, 81.6 and 434 mg/kg dm for Hg, Pb, Zn, Cu, Ni, Cr, Mn and Fe, respectively. The highest content of Cd was recorded in M. procera (3.05 mg/kg dm) and that of Co in L. quietus (0.90 mg/kg dm). The calculated weekly intake for Hg, Pb and Cd shows that regular consumption of mushrooms from the studied area poses risks to human health.     

Genomic erosion in a demographically recovered bird species during conservation rescue

The pink pigeon (Nesoenas mayeri) is an endemic species of Mauritius that has made a remarkable recovery after a severe population bottleneck in the 1970s to early 1990s. Prior to this bottleneck, an ex situ population was established from which captive-bred individuals were released into free-living subpopulations to increase population size and genetic variation. This conservation rescue led to rapid population recovery to 400–480 individuals, and the species was twice downlisted on the International Union for the Conservation of Nature (IUCN) Red List. We analyzed the impacts of the bottleneck and genetic rescue on neutral genetic variation during and after population recovery (1993–2008) with restriction site-associated sequencing, microsatellite analyses, and quantitative genetic analysis of studbook data of 1112 birds from zoos in Europe and the United States. We used computer simulations to study the predicted changes in genetic variation and population viability from the past into the future. Genetic variation declined rapidly, despite the population rebound, and the effective population size was approximately an order of magnitude smaller than census size. The species carried a high genetic load of circa 15 lethal equivalents for longevity. Our computer simulations predicted continued inbreeding will likely result in increased expression of deleterious mutations (i.e., a high realized load) and severe inbreeding depression. Without continued conservation actions, it is likely that the pink pigeon will go extinct in the wild within 100 years. Conservation rescue of the pink pigeon has been instrumental in the recovery of the free-living population. However, further genetic rescue with captive-bred birds from zoos is required to recover lost variation, reduce expression of harmful deleterious variation, and prevent extinction. The use of genomics and modeling data can inform IUCN assessments of the viability and extinction risk of species, and it helps in assessments of the conservation dependency of populations.     

Global pilot study for persistent organic pollutants (POPs) using PUF disk passive air samplers

Polyurethane foam (PUF) disks were deployed at global background sites, to test logistical issues associated with a global monitoring network for persistent organic pollutants (POPs). alpha-HCH, exhibited relatively high and uniform concentrations (17-150 pg/m3) at temperate and arctic sites with elevated concentrations associated with trans-Pacific inflow. Concentrations were much lower (<5 pg/m3) in Bermuda, Chile and Cape Grim. Concentrations for gamma-HCH, the main component of lindane, were spatially similar to the alpha-HCH pattern but lower in magnitude (typically, <10 pg/m3). Chlordane concentrations (sum of cis-chlordane, trans-chlordane and trans-nonachlor) were also low (<10 pg/m3). Dieldrin concentrations were in the range 2-25 pg/m3 at most sites but elevated in Bermuda. Back trajectories suggest that advection from Africa and the US may contribute. Endosulfan, a popular current-use pesticide, exhibited highest concentrations ranging from tens to hundreds of pg/m3. There was good agreement between duplicate samplers at each site and PUF disk-derived air concentrations agreed with high volume data. Few logistical/analytical problems were encountered in this pilot study.     

Impact of payments for environmental services and protected areas on local livelihoods and forest conservation in northern Cambodia

The potential impacts of payments for environmental services (PES) and protected areas (PAs) on environmental outcomes and local livelihoods in developing countries are contentious and have been widely debated. The available evidence is sparse, with few rigorous evaluations of the environmental and social impacts of PAs and particularly of PES. We measured the impacts on forests and human well‐being of three different PES programs instituted within two PAs in northern Cambodia, using a panel of intervention villages and matched controls. Both PES and PAs delivered additional environmental outcomes relative to the counterfactual: reducing deforestation rates significantly relative to controls. PAs increased security of access to land and forest resources for local households, benefiting forest resource users but restricting households’ ability to expand and diversify their agriculture. The impacts of PES on household well‐being were related to the magnitude of the payments provided. The two higher paying market‐linked PES programs had significant positive impacts, whereas a lower paying program that targeted biodiversity protection had no detectable effect on livelihoods, despite its positive environmental outcomes. Households that signed up for the higher paying PES programs, however, typically needed more capital assets; hence, they were less poor and more food secure than other villagers. Therefore, whereas the impacts of PAs on household well‐being were limited overall and varied between livelihood strategies, the PES programs had significant positive impacts on livelihoods for those that could afford to participate. Our results are consistent with theories that PES, when designed appropriately, can be a powerful new tool for delivering conservation goals whilst benefiting local people.