Remediation efficiency of vapour extraction of sandy soils contaminated with cyclohexane: influence of air flow rate, water and natural organic matter content

Abstract This work reports the analysis of the efficiency and time of soil remediation using vapour extraction as well as provides comparison of results using both, prepared and real soils. The main objectives were: (i) to analyse the efficiency and time of remediation according to the water and natural organic matter content of the soil; and (ii) to assess if a previous study, performed using prepared soils, could help to preview the process viability in real conditions. For sandy soils with negligible clay content, artificially contaminated with cyclohexane before vapour extraction, it was concluded that (i) the increase of soil water content and mainly of natural organic matter content influenced negatively the remediation process, making it less efficient, more time consuming, and consequently more expensive; and (ii) a previous study using prepared soils of similar characteristics has proven helpful for previewing the process viability in real conditions.

Casualties distribution in human and natural hazards

Catastrophic events, such as wars and terrorist attacks, big tornadoes and hurricanes, huge earthquakes, tsunamis, floods, and landslides, are always accompanied by a large number of casualties. The size distribution of these casualties have separately been shown to follow approximate power law (PL) distributions. In this paper, we analyze the number of victims of catastrophic phenomena, in particular, terrorism, and find double PL behavior. This means that the data set is better approximated by two PLs instead of one. We have plotted the two PL parameters corresponding to all terrorist events occurred in every year, from 1980 to 2010. We observe an interesting pattern in the chart, where the lines, that connect each pair of points defining the double PLs, are roughly aligned to each other.

Flavoured versus natural waters: macromineral (Ca, Mg, K, Na) and micromineral (Fe, Cu, Zn) contents

Macro (Ca, Mg, K, Na) and micromineral (Fe, Zn, Cu) composition of 39 waters was analysed. Determinations were made by atomic flame spectrophotometry for macrominerals and electrothermic atomisation in graphite furnace for microminerals. Mineral contents of still or sparkling natural waters (without flavours) changed from brand to brand. Mann–Whitney test was used to search for significant differences between flavoured and natural waters. For that, the concentration of each mineral was compared to the presence of flavours, preservatives, acidifying agents, fruit juice and/or sweeteners, according to the labelled composition. The statistical study demonstrated that flavoured waters generally have increased contents of K, Na, Fe and Cu. The added preservatives also led to significant differences in the mineral composition. Acidifying agents and fruit juice can also be correlated to the increase of Mg, K, Na, Fe and Cu. Sweeteners do not provide any significant difference in Ca, Mg, Fe and Zn contents.

Nutritional composition of low protein and phenylalanine-restricted dishes prepared for phenylketonuric patients

Nutritional management is essential for Phenylketonuria (PKU) treatment, consisting in a semi-synthetic and low phenylalanine (Phe) diet, which includes strictly controlled amounts of low protein natural foods (essentially fruits and vegetables) supplemented with Phe-free protein substitutes and dietetic low-protein products. PKU diet has to be carefully planned, providing the best ingredient combinations, so that patients can achieve good metabolic control and an adequate nutritional status. Hereupon, it is mandatory to know the detailed composition of natural and/or cooked foodstuffs prepared specifically for these patients. We intended to evaluate sixteen dishes specifically prepared for PKU patients, regarding the nutritional composition, Phe and tyrosine (Tyr) contents, fatty acids profile, and vitamins E and B12 amounts. The nutritional composition of the cooked samples was 15.5–92.0 g/100 g, for moisture; 0.7–3.2 g/100 g, for protein; 0.1–25.0 g/100 g, for total fat; and 5.0–62.0 g/100 g, for total carbohydrates. Fatty acids profile and vitamin E amount reflected the type of fat used. All samples were poor in vitamin B12 (0.3–0.8 μg/100 g). Boiled rice presented the highest Phe content: 50.3 mg/g of protein. These data allow a more accurate calculation of the diet portions to be ingested by the patients according to their individual tolerance.

Remediation of sandy soils contaminated with hydrocarbons and halogenated hydrocarbons by soil vapour extraction

This paper presents the study of the remediation of sandy soils containing six of the most common contaminants (benzene, toluene, ethylbenzene, xylene, trichloroethylene and perchloroethylene) using soil vapour extraction (SVE). The influence of soil water content on the process efficiency was evaluated considering the soil type and the contaminant. For artificially contaminated soils with negligible clay contents and natural organic matter it was concluded that: (i) all the remediation processes presented efficiencies above 92%; (ii) an increase of the soil water content led to a more time-consuming remediation; (iii) longer remediation periods were observed for contaminants with lower vapour pressures and lower water solubilities due to mass transfer limitations. Based on these results an easy and relatively fast procedure was developed for the prediction of the remediation times of real soils; 83% of the remediation times were predicted with relative deviations below 14%.

Sequential application of soil vapor extraction and bioremediation processes for the remediation of ethylbenzene-contaminated soils

Soil vapor extraction (SVE) is an efficient, well-known and widely applied soil remediation technology. However, under certain conditions it cannot achieve the defined cleanup goals, requiring further treatment, for example, through bioremediation (BR). The sequential application of these technologies is presented as a valid option but is not yet entirely studied. This work presents the study of the remediation of ethylbenzene (EB)-contaminated soils, with different soil water and natural organic matter (NOMC) contents, using sequential SVE and BR. The obtained results allow the conclusion that: (1) SVE was sufficient to reach the cleanup goals in 63% of the experiments (all the soils with NOMC below 4%), (2) higher NOMCs led to longer SVE remediation times, (3) BR showed to be a possible and cost-effective option when EB concentrations were lower than 335 mg kgsoil −1, and (4) concentrations of EB above 438 mg kgsoil −1 showed to be inhibitory for microbial activity.

Survey of trace elements (Al, As, Cd, Cr, Co, Hg, Mn, Ni, Pb, Se, and Si) in retail samples of flavoured and bottled waters

Concentrations of eleven trace elements (Al, As, Cd, Cr, Co, Hg, Mn, Ni, Pb, Se, and Si) were measured in 39 (natural and flavoured) water samples. Determinations were performed using graphite furnace electrothermetry for almost all elements (Al, As, Cd, Cr, Co, Mn, Ni, Pb, and Si). For Se determination hydride generation was used, and cold vapour generation for Hg. These techniques were coupled to atomic absorption spectrophotometry. The trace element content of still or sparkling natural waters changed from brand to brand. Significant differences between natural still and natural sparkling waters (p<0.001) were only apparent for Mn. The Mann–Whitney U-test was used to search for significant differences between flavoured and natural waters. The concentration of each element was compared with the presence of flavours, preservatives, acidifying agents, fruit juice and/or sweeteners, according to the labelled composition. It was shown that flavoured waters generally increase the trace element content. The addition of preservatives and acidifying regulators had a significant influence on Mn, Co, As and Si contents (p<0.05). Fruit juice can also be correlated to the increase of Co and As. Sweeteners did not provide any significant difference in Mn, Co, Se and Si content.

Remediation of soils combining soil vapor extraction and bioremediation: benzene

This work reports the study of the combination of soil vapor extraction (SVE) with bioremediation (BR) to remediate soils contaminated with benzene. Soils contaminated with benzene with different water and natural organic matter contents were studied. The main goals were: (i) evaluate the performance of SVE regarding the remediation time and the process efficiency; (ii) study the combination of both technologies in order to identify the best option capable to achieve the legal clean up goals; and (iii) evaluate the influence of soil water content (SWC) and natural organic matter (NOM) on SVE and BR. The remediation experiments performed in soils contaminated with benzene allowed concluding that: (i) SVE presented (a) efficiencies above 92% for sandy soils and above 78% for humic soils; (b) and remediation times from 2 to 45 h, depending on the soil; (ii) BR showed to be an efficient technology to complement SVE; (iii) (a) SWC showed minimum impact on SVE when high airflow rates were used and led to higher remediation times for lower flow rates; (b) NOM as source of microorganisms and nutrients enhanced BR but hindered the SVE due the limitation on the mass transfer of benzene from the soil to the gas phase.

Phenylketonuria: Protein content and amino acids profile of dishes for phenylketonuric patients. The relevance of phenylalanine

Phenylketonuria is an inborn error of metabolism, involving, in most cases, a deficient activity of phenylalanine hydroxylase. Neonatal diagnosis and a prompt special diet (low phenylalanine and natural-protein restricted diets) are essential to the treatment. The lack of data concerning phenylalanine contents of processed foodstuffs is an additional limitation for an already very restrictive diet. Our goals were to quantify protein (Kjeldahl method) and amino acid (18) content (HPLC/fluorescence) in 16 dishes specifically conceived for phenylketonuric patients, and compare the most relevant results with those of several international food composition databases. As might be expected, all the meals contained low protein levels (0.67–3.15 g/100 g) with the highest ones occurring in boiled rice and potatoes. These foods also contained the highest amounts of phenylalanine (158.51 and 62.65 mg/100 g, respectively). In contrast to the other amino acids, it was possible to predict phenylalanine content based on protein alone. Slight deviations were observed when comparing results with the different food composition databases.

Joint effects of salinity and the antidepressant sertraline on the estuarine decapod Carcinus maenas

Concurrent exposure of estuarine organisms to man-made and natural stressors has become a common occurrence. Numerous interactions of multiple stressors causing synergistic or antagonistic effects have been described. However, limited information is available on combined effects of emerging pharmaceuticals and natural stressors. This study investigated the joint effects of the antidepressant sertraline and salinity on Carcinus maenas. To improve knowledge about interactive effects and potential vulnerability,experiments were performed with organisms from two estuaries with differing histories of exposure to environmental contamination. Biomarkers related to mode of action of sertraline were employed to assess effects of environmentally realistic concentrations of sertraline at two salinity levels. Synergism and antagonism were identified for biomarkers of cholinergic neurotransmission, energy production,anti-oxidant defences and oxidative damage. Different interactions were found for the two study sites highlighting the need to account for differences in tolerance of local ecological receptors in risk evaluations.

Synthesis of molecular biomimetics

Biomimetics has paved the way toward new materials and technologies inspired in Nature. Biomolecules and their supramolecular organization have today a leading role in biomimetics, benefiting from the recent advances in nanotechnology. The production of biomimetic materials may be however a difficult task, because Nature does it very well. The use of several building blocks assembled in bottom-up arrangement is without doubt at the core of this process. Such building blocks include different molecules or molecular arrangements, of synthetic or natural origin, such as amino acids, lipids, carbohydrates, nucleic acids, carbon allotropes, dendrimers, or organosilanes, among others. The most common approaches to produce synthetic biomimetic materials are reported herein, with special emphasis to building blocks and their supramolecular arrangement.

Exploring the long-term associations between adolescents’ music training and academic achievement

There is a positive relationship between learning music and academic achievement, although doubts remain regarding the mechanisms underlying this association. This research analyses the academic performance of music and non-music students from seventh to ninth grade. The study controls for socioeconomic status, intelligence, motivation and prior academic achievement. Data were collected from 110 adolescents at two time points, once when the students were between 11 and 14 years old in the seventh grade, and again 3 years later. Our results show that music students perform better academically than non-music students in the seventh grade (Cohen’s d = 0.88) and in the ninth grade (Cohen’s d = 1.05). This difference is particularly evident in their scores in Portuguese language and natural science; the difference is somewhat weaker in history and geography scores, and is least pronounced in mathematics and English scores (η2 p from .09 to .21). A longitudinal analysis also revealed better academic performance by music students after controlling for prior academic achievement (η2 p = .07). Furthermore, controlling for intelligence, socioeconomic status and motivation did not eliminate the positive association between music learning from the seventh to the ninth grade and students’ academic achievement (η2 p = .06). During the period, music students maintained better and more consistent academic standing. We conclude that, after controlling for intelligence, socioeconomic status and motivation, music training is positively associated with academic achievement.