Modeling road building,deforestation and carbon emissions due deforestation in the Ecuadorian Amazon: the potential impact of oil frontier growth

In the Ecuadorian Amazon roads play the major role in transforming land cover. Since the beginning of the oil development in this region, oil exploration and road building have been linked. The objectives of this paper are twofold: First, to present a scenario of future deforestation as result of expanding the oil frontier in the Ecuadorian Amazon until the year 2030. Second, to produce an analysis of possible carbon emission scenarios as results of the deforestation produced. This paper tries to shed light into how the development of new oil concessions impact land associated environmental services. The paper uses spatial explicit simulations, that are based on parameters built using past land transitions from areas that experimented oil development, and that explain possible outcomes in the year 2030 using current and predicted road network. Simulations indicate that under current transition probabilities and a conservative scenario road construction, more than 2 million hectares will be affected, which is 35% of the area covered by concessions, which would release 51 to 148 MT of carbon to the atmosphere. This paper illustrates the strong links between road building and deforestation, where even small amount of road construction can have large effects on land cover.     

Assessment of polychlorinated dibenzo-p-dioxin and dibenzofuran emissions from a hazardous waste incineration plant using long-term sampling equipment

The aim of this work is to evaluate the performance of a continuous monitoring system for the analysis of the mass concentration of PCDD/Fs from stationary sources. Data was acquired from a modern, state of the art, hazardous waste thermal treatment plant for a period of more than 2 years using a commercial available continuous monitoring system. The study consisted of a total of 16 samples, collected in periods from 1 week to 2 months resulting in an average of 360 m³ sampled flue gas per sample. The study showed the system was able to confirm that for a period of more than 2 years the plant was complying with the limit of 0.1 ng I-TEQ/Nm³. In addition, the data showed the typical fingerprint of such installations which is useful for example in impact studies. Long-term samples were compared to five short-term samples (6 h) collected every 6 months during the study period. Principal component analysis was applied to PCDD/Fs obtained data as useful statistical tool to find out trends and similarities between different samples. Improvement in terms of representativeness of data was achieved through continuous assessment since the starts of the project. The obtained data was further used to determine the emission factor for this activity and the total annual PCDD/Fs release to the atmosphere.     

Organochlorine concentrations in franciscana dolphins, Pontoporia blainvillei, from Brazilian waters

Blubber samples were collected from ten franciscana dolphins either incidentally captured in fishing operations or stranded on São Paulo (SP) and Paraná (PR) states littoral, Southeastern and Southern Brazilian coast, respectively. Determination of PCB, DDT and HCB concentrations were performed by capillary gas chromatograph coupled to electron capture detector (ECD). ΣDDT, ΣPCB and HCB concentrations ranged from 264 ng g⁻¹ to 5811 ng g⁻¹ lipid, from 909 ng g⁻¹ to 5849 ng g⁻¹ lipid and from 10 ng g⁻¹ to 61 ng g⁻¹ lipid, respectively. Regarding DDTs, the distribution of the mean percentages decreased in the following order: p,p′-DDE > p,p′-DDD > p,p′-DDT. The ΣDDT/ΣPCB ratio varied between 0.27 and 0.42 in Northern and Central SP coast, while in Southern SP and PR coast the values were 1.6 and 1.9, respectively. Dissimilarities in ΣDDT/ΣPCB ratios point to different sources of organochlorine compounds to franciscana dolphins in the study area. Considering the endocrine disruptive action of organochlorine compounds, the concentrations found in franciscana dolphins from Brazilian waters may represent an additional obstacle to the conservation of this endangered cetacean species.     

Microbial community response to addition of polylactate compounds to stimulate hexavalent chromium reduction in groundwater

To evaluate the efficacy of bioimmobilization of Cr(VI) in groundwater at the Department of Energy Hanford site, we conducted a series of microcosm experiments using a range of commercial electron donors with varying degrees of lactate polymerization (polylactate). These experiments were conducted using Hanford Formation sediments (coarse sand and gravel) immersed in Hanford groundwater, which were amended with Cr(VI) and several types of lactate-based electron donors (Hydrogen Release Compound, HRC; primer-HRC, pHRC; extended release HRC) and the polylactate-cysteine form (Metal Remediation Compound, MRC). The results showed that polylactate compounds stimulated an increase in bacterial biomass and activity to a greater extent than sodium lactate when applied at equivalent carbon concentrations. At the same time, concentrations of headspace hydrogen and methane increased and correlated with changes in the microbial community structure. Enrichment of Pseudomonas spp. occurred with all lactate additions, and enrichment of sulfate-reducing Desulfosporosinus spp. occurred with almost complete sulfate reduction. The results of these experiments demonstrate that amendment with the pHRC and MRC forms result in effective removal of Cr(VI) from solution most likely by both direct (enzymatic) and indirect (microbially generated reductant) mechanisms.     

The use of hard- and soft-modelling to predict radiostrontium solid-liquid distribution coefficients in soils

The solid-liquid distribution coefficient (K_d) is the parameter that governs the incorporation of contaminants in soils. Its estimation allows the prediction of the fate of contaminants in the short- and long-term after a contamination event. Here, the K_d of radiostrontium (K_d(Sr)), a radionuclide of significant environmental interest, was predicted by hard models, which are based on knowledge of the mechanisms governing its sorption, and by soft models based on Partial Least Squares (PLS), using a large data set with the main soil parameters. The two approaches were tested and compared for 30 soils in Spain. Correlations between the predicted and experimental values of K_d(Sr) obtained using hard- and soft-modelling showed slopes close to 1 and regression coefficients higher than 0.95, which confirms that both approaches are able to obtain satisfactory estimates for K_d(Sr) from soil parameters.     

Effectiveness of three bulking agents for food waste composting

Rather than landfilling, composting the organic fraction of municipal solid wastes recycles the waste as a safe and nutrient enriched soil amendment, reduces emissions of greenhouse gases and generates less leachate. The objective of this project was to investigate the composting effectiveness of three bulking agents, namely chopped wheat (Triticum) straw, chopped mature hay consisting of 80% timothy (milium) and 20% clover (triphullum) and pine (pinus) wood shavings. These bulking agents were each mixed in duplicates at three different ratios with food waste (FW) and composted for 10 days using prototype in-vessel composters to observe their temperature and pH trends. Then, each mixture was matured in vertical barrels for 56 days to measure their mass loss and final nutrient content and to visually evaluate their level of decomposition. Chopped wheat straw (CWS) and chopped hay (CH) were the only two formulas that reached thermophilic temperatures during the 10 days of active composting when mixed with FW at a wet mass ratio of 8.9 and 8.6:1 (FW:CWS and FW:CH), respectively. After 56 days of maturation, these two formulas were well decomposed with no or very few recognizable substrate particles, and offered a final TN exceeding the original. Wood shavings (WS) produced the least decomposed compost at maturation, with wood particles still visible in the final product, and with a TN lower than the initial. Nevertheless, all bulking agents produced compost with an organic matter, TN, TP and TK content suitable for use as soil amendment.     

New best estimates for radionuclide solid–liquid distribution coefficients in soils. Part 2. Naturally occurring radionuclides

Predicting the transfer of radionuclides in the environment for normal release, accidental, disposal or remediation scenarios in order to assess exposure requires the availability of an important number of generic parameter values. One of the key parameters in environmental assessment is the solid liquid distribution coefficient, K_d, which is used to predict radionuclide–soil interaction and subsequent radionuclide transport in the soil column. This article presents a review of K_d values for uranium, radium, lead, polonium and thorium based on an extensive literature survey, including recent publications. The K_d estimates were presented per soil groups defined by their texture and organic matter content (Sand, Loam, Clay and Organic), although the texture class seemed not to significantly affect K_d. Where relevant, other K_d classification systems are proposed and correlations with soil parameters are highlighted. The K_d values obtained in this compilation are compared with earlier review data.     

Sorption of perfluoroalkyl substances in sewage sludge

The sorption behaviour of three perfluoroalkyl substances (PFASs) (perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA) and perfluorobutanesulfonic acid (PFBS)) was studied in sewage sludge samples. Sorption isotherms were obtained by varying initial concentrations of PFOS, PFOA and PFBS. The maximum values of the sorption solid–liquid distribution coefficients (K_d,max) varied by almost two orders of magnitude among the target PFASs: 140–281 mL g^?1 for PFOS, 30–54 mL g^?1 for PFOA and 9–18 mL g^?1 for PFBS. Freundlich and linear fittings were appropriate for describing the sorption behaviour of PFASs in the sludge samples, and the derived K_F and K_d,linear parameters correlated well. The hydrophobicity of the PFASs was the key parameter that influenced their sorption in sewage sludge. Sorption parameters and log(K_OW) were correlated, and for PFOS (the most hydrophobic compound), pH and Ca?+?Mg status of the sludge controlled the variation in the sorption parameter values. Sorption reversibility was also tested from desorption isotherms, which were also linear. Desorption parameters were systematically higher than the corresponding sorption parameters (up to sixfold higher), thus indicating a significant degree of irreversible sorption, which decreased in the sequence PFOS?>?PFOA?>?PFBS.     

Distribution of metals and trace elements in adult and juvenile penguins from the Antarctic Peninsula area

The presence of metals in the Antarctic environment is principally a natural phenomenon caused by geochemical characteristics of the region, although some anthropogenic activities can increase these natural levels. Antarctic penguins present several of the characteristics of useful sentinels of pollution in Antarctica such as they are long-lived species situated at the top of food web. The concentrations of Al, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Cd, and Pb were determined by inductively coupled plasma–mass spectrometry in samples of liver, kidney, muscle, bone, feather, and stomach contents of gentoo, chinstrap, and Adélie penguin (12 adults, five juveniles) from carcasses of naturally dead individuals collected opportunistically in the Antarctic Peninsula area. The obtained results showed that accumulation and magnification of several elements can be occurring, so that Cd and Se reached levels potentially toxic in some specimens. The presence of human activities seems to be increasing the presence of toxic metals such as Mn, Cr, Ni, or Pb in penguins.     

Charcoal burning as a source of polyaromatic hydrocarbons in waterpipe smoking

Polyaromatic hydrocarbons (PAH) content from seven commercial waterpipe charcoals were determined during the smoking process to estimate how much PAHs would not be trapped by the water trap and could reach the lungs of the smokers. Naphthalene, 2-methylnaphthalene, acenaphthylene, acenaphthene, phenanthrene and fluoranthene were the most abundant PAH compounds produced during smoking. Naphthalene was the highest in all of the smoke contents and levels of 5 to 405 μg/15 minutes could be inhaled by the smoker. The amounts of PAHs produced during the smoking events in absence of tobacco varied greatly among different brands of charcoal. The amount and composition of the emitted PAH were not related to the amount and composition of the original chemicals in the charcoal prior to burning. Our findings suggest that public health agencies should regulate smoked charcoal products alongside tobacco.