Simulation and life cycle assessment of process design alternatives for biodiesel production from waste vegetable oils

This study uses the process simulator ASPEN Plus^® and Life Cycle Assessment (LCA) to compare three process design alternatives for biodiesel production from waste vegetable oils that are: the conventional alkali-catalyzed process including a free fatty acids (FFAs) pre-treatment, the acid-catalyzed process, and the supercritical methanol process using propane as co-solvent. Results show that the supercritical methanol process using propane as co-solvent is the most environmentally favorable alternative. Its smaller steam consumption in comparison with the other process design alternatives leads to a lower contribution to the potential environmental impacts (PEI’s). The acid-catalyzed process generally shows the highest PEI’s, in particular due to the high energy requirements associated with methanol recovery operations.     

Levels and risks of particulate-bound PAHs in indoor air influenced by tobacco smoke: a field measurement

Considering tobacco smoke as one of the most health-relevant indoor sources, the aim of this work was to further understand its negative impacts on human health. The specific objectives of this work were to evaluate the levels of particulate-bound PAHs in smoking and non-smoking homes and to assess the risks associated with inhalation exposure to these compounds. The developed work concerned the application of the toxicity equivalency factors approach (including the estimation of the lifetime lung cancer risks, WHO) and the methodology established by USEPA (considering three different age categories) to 18 PAHs detected in inhalable (PM₁₀) and fine (PM_2.5) particles at two homes. The total concentrations of 18 PAHs (Σ_PAHs) was 17.1 and 16.6 ng m^?3 in PM₁₀ and PM_2.5 at smoking home and 7.60 and 7.16 ng m^?3 in PM₁₀ and PM_2.5 at non-smoking one. Compounds with five and six rings composed the majority of the particulate PAHs content (i.e., 73 and 78 % of Σ_PAHs at the smoking and non-smoking home, respectively). Target carcinogenic risks exceeded USEPA health-based guideline at smoking home for 2 different age categories. Estimated values of lifetime lung cancer risks largely exceeded (68–200 times) the health-based guideline levels at both homes thus demonstrating that long-term exposure to PAHs at the respective levels would eventually cause risk of developing cancer. The high determined values of cancer risks in the absence of smoking were probably caused by contribution of PAHs from outdoor sources.     

Solid-waste management in the rural area of BRAZIL: a case study in Quilombola communities

Although there has been a worldwide growing concern regarding solid-waste management, the rural area has been left behind on this matter. It is common knowledge that the lack of waste management is very detrimental to the environment and impact seriously the public health. Therefore, the aim of this work is to contribute to the decision-making process regarding waste management in the rural area by proposing a new methodology using the combination of risk analysis and complementary sustainability criteria. The proposed methodology was demonstrated through a case study in the State of Mato Grosso do Sul, Brazil. A field survey was performed to define the current scenarios and three new scenarios were proposed. The risk analysis showed that the major risk to which residents are vulnerable to is the appearance of vectors that can cause various types of diseases. Besides that, only 30% of rural Quilombola communities of Mato Grosso do Sul have waste collection and the predominant scenario is the burning of dry waste and use of organic waste for animal feeding. Using the complementary relevant criteria, the most suitable scenario do the studied communities would be the combination of household composting and source separation of dry waste. The proposed methodology can be easily applied to other rural regions seeking for sustainable waste management systems.     

Effects of insecticides used in strawberries on stingless bees Melipona quadrifasciata and Tetragonisca fiebrigi (Hymenoptera: Apidae)

Environmental Science and Pollution Research - The use of pesticides is considered one of the most important threats to pollinators, especially since they are widely used in agriculture for pest...     

A temporal and spatial monitoring of organotin pollution in a harborside region of Brazil by imposex and ecological quality ratio using <Emphasis Type="Italic">Leucozonia nassa</Emphasis>

This study represents the first use of Leucozonia nassa (Mollusca-Gastropoda) in a program of long-term monitoring. Specimens of L. nassa were collected between 2006 and 2014 and analyzed for the occurrence of imposex in two areas in Southeastern Brazil, one control area and another characterized by the presence of many ports and marinas. Imposex was evaluated in nine sites based on the percentage of females exhibiting imposex (I%), relative penis length index and vas deferens sequence index, classical indices to evaluate tributyltin (TBT) impacts. Moreover, this study uses for the first time in a tropical environment the ecological quality ratio (EQR), an approach to verify the imposex levels as an indicator of the impact by organotin compounds according to the EU Water Framework Directive. The results confirm the occurrence of high levels of imposex in L. nassa with all the indices evaluated. Furthermore, the results also indicate that, despite the international ban, antifouling paints based on TBT are still possibly used in Brazil. In addition, this study shows that L. nassa has the characteristics that make it a suitable bioindicator to monitor TBT pollution, and that the use of the EQR may create important data regarding this problem.     

Cytotoxicity and genotoxicity of Guaribas river water (Piauí, Brazil), influenced by anthropogenic action

In general, tropical rivers have a great impact on human activities. Bioaccumulation of toxins is a worldwide problem nowadays and has been, historically, overlooked by the supervisory authorities. This study evaluated cytogenotoxic effects of Guaribas river (a Brazilian river) water during dry and rainy seasons of 2014 by using the Allium cepa test system. The toxicogenetic variables, including root growth, mitotic index, and chromosomal aberrations, were analyzed in meristematic cells of A. cepa exposed to water samples taken from the up-, within, and downstream of the city Picos (state: Piauí). The physical-chemical parameters were also analyzed to explain water quality and possible anthropogenic action. Additionally, the presence of heavy metals was also analyzed to explain water quality and possible damaging effects on eukaryotic cells. The results suggest that the river water exerted cytotoxic, mutagenic, and genotoxic effects, regardless of the seasons. In addition, Guaribas river presented physico-chemical values outside the Brazilian laws, which can be a characteristic of human pollution (domestic sewage, industrial, and local agriculture). The genetic damage was positively correlated with higher levels of heavy metals. The pollution of the Guaribas river water may link to the chemical contamination, including the action of heavy metals and their impacts on genetic instability in the aquatic ecosystem. In conclusion, necessary steps should be taken into account for further toxicogenetic studies of the Guaribas river water, as it has an influence in human health of the same region of Brazil.     

Mass balance to assess the efficiency of a mechanical-biological treatment

Using mechanical-biological treatment of residual municipal solid waste, it is possible to significantly lower landfill volume and gas and leachate emissions. Moreover, the landfill characteristics are improved. The performance of the Mende (France) mechanical-biological treatment plant is assessed via mass balances coupled with manual sorting according to the MODECOMtrade mark methodology and biochemical methane potential after 90 days of incubation. The site includes mechanical sorting operations, a rotary sequential bioreactor, controlled aerobic stabilisation corridors, maturation platforms, and a sanitary landfill site for waste disposal in separated cells. Results showed that several steps could be improved: after a first sieving step, about 12% of the potentially biodegradable matter is landfilled directly without any treatment; mechanical disintegration of papers and cardboards in the rotary sequential bioreactor is insufficient and leads to a high proportion of papers and cardboards being landfilled without further treatment. Two fine fractions go through stabilisation and maturation steps. At the end of the maturation step, about 54% of the potentially biodegradable matter is degraded. The biochemical methane potential after 90 days of incubation is reduced by 81% for one of the two fine fractions and reduced by 88% for the other one. Considering the whole plant, there is a reduction of nearly 20% DM of the entering residual municipal solid waste.     

Microcystins and cyanobacteria trends in a 14 year monitoring of a temperate eutrophic reservoir (Aguieira, Portugal)

A monitoring program of cyanobacteria and cyanotoxins in the framework of the surveillance of the Water Treatment Plant efficiency of the municipality of Santa Comba D?o (Portugal) was conducted from 1994 until 2007. With these data we aimed to answer the question, are MCs produced evenly over the years in a single water body? Samples were taken by the local health authorities in the site of the Water treatment plant and analyzed for total phytoplankton, cyanobacteria and the hepatotoxic cyanotoxins microcystins (MCs). Apart from 1999 and 2000, cyanobacteria represented a high proportion of total phytoplankton, attaining during several months of the year more than 90% of total phytoplankton density. A total of 24 cyanobacteria species were identified and Microcystis aeruginosa, Anabaena flos-aquae and Aphanizomenon flos-aquae were the main potentially toxic cyanobacteria species present throughout the period. MC concentration varied between 0.3 μg MC-LR eq l?1 in October 98 and 87.0 μg MC-LR eq l?1 in September 2001. The evolution of the average cell quota does not reveal any especial trend, although in 2001 the quota was the highest but not significantly different from the other years. The threshold limit of 5000 cells per ml of Microcystis aeruginosa should be taken into consideration in monitoring programs because the 10,000 cells per ml proposed by several other national programs might not be enough to prevent human health risks. Due to high annual variation in MC cell quota, monitoring programs of cyanobacteria and MC should be extended in time, since short term studies do not provide us the data needed for a safe management of a water body used for human purposes.     

Nonapeptide levels in male cleaner fish brains during interactions with unfamiliar intra and interspecific partners

Behavioral Ecology and Sociobiology - A growing body of research suggests that songs are an important part of the courtship behavior of many bat species, however there is little information on the...     

Population structure and connectivity of the European conger eel (Conger conger) across the north-eastern Atlantic and western Mediterranean: integrating molecular and otolith elemental approaches

Genetic variation (mtDNA) of the European conger eel, Conger conger, was compared across five locations in the north-eastern Atlantic (Madeira, Azores, South Portugal, North Portugal and Ireland) and one location in the western Mediterranean (Mallorca). Genetic diversity of conger eel was high, and differentiation among regions was not significant. Additionally, comparisons of element:Ca ratios (Sr:Ca, Ba:Ca, Mn:Ca and Mg:Ca) in otolith cores (larval phase) and edges (3?months prior to capture) among the Azores, North Portugal, Madeira and Mallorca regions for 2?years indicated that variation among regions were greater for edges than cores. Therefore, while benthic conger may display residency at regional scales, recruitment may not necessarily be derived from local spawning and larval retention. Furthermore, data from otoliths suggest a separated replenishment source for western Mediterranean and NE Atlantic stocks. The combination of genetics and otolith chemistry suggests?a population model for conger eel involving a broad-scale dispersal of larvae, with limited connectivity for benthic juvenile life stages at large spatial scales, although the existence of one or multiple spawning grounds for the species remains uncertain.