CO2 leakage simulation: effects of the pH decrease on fertilisation and larval development of Paracentrotus lividus and sediment metals toxicity

Carbon capture and storage has become a new mitigation option to reduce anthropogenic CO₂ emissions. The effects of the CO₂-related acidification, associated with unpredictable leaks of CO₂ during the operational phases were studied using the Paracentrotus lividus sea urchin-liquid-phase-assays (fertilisation and embryo-larval development tests). Besides to the direct effects of the CO₂-associated pH decrease, the possible effects on marine sediment toxicity were studied by exposing the urchin larvae to elutriate of sediments with different metals concentration, which were subjected to various pH treatments. The resulted median toxic effect pH ranged from 6.33?±?0.02 and 6.91?±?0.01 for the egg fertilisation, and between 6.66?±?0.03 and 7.16?±?0.01 for the larval development assays. Concentrations of Co, Zn, As, Cu, and Fe were detected in the sediment elutriates. For all the sediment elutriates tested the amount of the dissolved Zn increased in parallel with the pH reductions. Correlated effects of acidification, biological response, and the presence of dissolved metals were observed in this work evidencing that the most important factor controlling the reduction of egg fertilisation and larval development success was the combined effects of the reduction of pH and the presence of the contaminants (mainly Zn, Co, and As).     

Optimization of integrated water quality management for agricultural efficiency and environmental conservation

The scarcity of water resources in Egypt has necessitated the use of various types of lower quality water. Agricultural drainage water is considered a strategic reserve for meeting increasing freshwater demands. In this study, a novel model series was applied to a drainage basin in the Nile Delta to optimize integrated water quality management for agriculture and the aquatic environment. The proposed model series includes a waste load allocation model, an export coefficient model, a stream water quality model, and a genetic algorithm. This model series offers an optimized solution for determining the required removal levels of total suspended solids (TSS), the chemical oxygen demand (COD) at point and non-point pollution sources, and the source flows that require treatment to meet a given water quality target. The model series was applied during the summer and winter to the El-Qalaa basin in the western delta of the Nile River. Increased pollutant removal and treated fractions at point and non-point sources reduced violations of the TSS standards from 732.6 to 238.9 mg/L in summer and from 543.1 to 380.9 mg/L in winter. Likewise, violations of the COD standards decreased from 112.4 mg/L to 0 (no violations) in summer and from 91.7 mg/L to no violations in winter. Thus, this model is recommended as a decision support tool for determining a desirable waste load allocation solution from a trade-off curve considering costs and the degree of compliance with water quality standards.     

Pesticide adsorption on a calcareous soil modified with sewage sludge and quaternary alkyl-ammonium cationic surfactants

BACKGROUND, AIM AND SCOPE: Pesticides are often found in soil as a result of their application to control pests. They can be transported on soil particles to surface waters or they can lixiviate and reach other environmental compartments. Soil modification with amendments, such as sewage sludge, and with surfactants, h been proposed to reduce pesticide environmental fate. METHODS: The sorption of atrazine, methidathion and diazinon using the batch technique has been studied on non-modified soil and soil modified with sewage sludge and cationic surfactants, as well as the effect of their addition on soil properties such as organic carbon (OC) content and exchange cations. RESULTS AND DISCUSSION: The OC content of the surfactant modified soils was the highest with the surfactant with the longest hydrocarbon chain (hexadecyltrimethyl ammonium bromide, HDTMA). The results of the OC content run in parallel with the increase in pesticide retention. When the sorption was n malized to soil OC content, the retention induced by addition of HDTMA was still the highest, which is an indication that the organic matter derived from the organic cations is a more effective medium to retain dissolved contaminants, than organic matter from native soil. The addition of sewage sludge to the soil did only result in a slight increase of the soil CEC and, hence, moderately affected the ability of the cationic surfactant to retain the pesticides. CONCLUSIONS: The addition of cationic surfactants to soil would possibly reduce the movement to groundwater of atrazine, methidathion and diazinon. In the case of HDTMA, the decrease in sorption at high surfactant loadings was very slow, being that the surfactant was able to retain the pesticides at concentration values which clearly exceeded the monolayer coverage. RECOMMENDATIONS AND PERSPECTIVES: Contamination by pesticides, which are present in the soil due to their direct input in this medium or to spills or illegal tipping, may be hindered from migration to groundwater by application of a cationic surfactant.     

A new FTIR method to monitor transesterification in biodiesel production by ultrasonication

New renewable fuels are urgently needed due to increasing fossil fuel pollution. Biodiesel, which contains alkyl esters produced by transesterification of oils, is an alternative fuel. Nevertheless, the main problem of biodiesel is its high price. Costs can be reduced by replacement of the current homogeneous catalysts by heterogeneous catalysts; however, research for new catalysts is actually slowed by lengthy analytical techniques. Here, we set up a simple and rapid analytical method using Fourier transform infrared (FTIR) to monitor transesterification. Conversion of sunflower and recycled cooking oils to their corresponding methyl esters was easily measured using a linear correlation between the intensity of an infrared peak at 1,437 cm^?1 and the percent conversion. The results obtained by infrared were validated by gas chromatography. We also studied the effect of 20 kHz ultrasonic irradiation on biodiesel synthesis. Using our FTIR method, we found that replacing mechanical stirring with an ultrasonic probe leads to quality biodiesel in 10 min for sunflower oil and 20 min for recycled cooking oil.     

A case of ring chromosome 22 with deletion of the 22q13.3 region associated with agenesis of the corpus callosum,fornix and septum pellucidum

We report a 16-week-gestation foetus obtained by voluntary abortion after prenatal diagnosis, in which a ring chromosome 22 was observed with deletion of the 22q13.3 region. A prenatal study of the amniotic fluid by standard chromosome technique with G bands and FISH (fluorescence in situ hybridisation) was performed. After the abortion, the anatomopathological study of the obtained foetus was carried out. Morphological and histological analysis of the foetus did not reveal severe physical abnormalities, although alterations of the nervous system were observed consisting of corpus callosum, fornix and septum pellucidum agenesia. It could be that the genes in this region that were involved in the development of the central nervous system were responsible for the alterations found in the morphological study. The wide range of manifestations observed in patients with this cytogenetic alteration is probably due to size differences in the deleted region. Copyright © 2004 John Wiley & Sons, Ltd.     

Active oxygen doctors the evidence

Investigation at the scene of a crime begins with the search for clues. In the case of bloodstains, the most frequently used reagents are luminol and reduced phenolphthalein (or phenolphthalin that is also known as the Kastle–Meyer colour test). The limitations of these reagents have been studied and are well known. Household cleaning products have evolved with the times, and new products with active oxygen are currently widely used, as they are considered to be highly efficient at removing all kinds of stains on a wide range of surfaces. In this study, we investigated the possible effects of these new cleaning products on latent bloodstains that may be left at a scene of a crime. To do so, various fabrics were stained with blood and then washed using cleaning agents containing active oxygen. The results of reduced phenolphthalein, luminol and human haemoglobin tests on the washed fabrics were negative. The conclusion is that these new products alter blood to such an extent that it can no longer be detected by currently accepted methods employed in criminal investigations. This inability to locate bloodstains means that highly important evidence (e.g. a DNA profile) may be lost. Consequently, it is important that investigators are aware of this problem so as to compensate for it.

Biomonitoring of chemical elements in an urban environment using arboreal and bush plant species

Purpose  

The aim of this work was to investigate the possibility of using several bush and arboreal plant species, usually present as ornamental plants in street and parks, as environmental indicators of pollution. This is a research paper that evaluates the real possibility of using a fast and low-cost procedure to evaluate the pollution degree through data obtained from plant species growing within an urban environment.     

Prenatal diagnosis of fragile x syndrome: (cgg)n expansion and methylation of chorionic villus samples

Fragile X syndrome is the most common form of inherited mental retardation, due to an expansion of the (CGG)_n trinucleotide repeat in the FMR-1 gene and hypermethylation of its 5′ upstream CpG island. Two major problems remain to be resolved for fragile X prenatal diagnosis: the abnormal methylation patterns of chorionic villus samples (CVS) and the inability to predict the mental status of females with the full mutation. We present here the results of ten prenatal diagnoses of fragile X syndrome using Southern blotting and polymerase chain reaction (PCR) amplification, and the analysis of 50 further CVS to test the methylation status of the CpG island of the FMR-1 gene. In the ten ‘at-risk’ CVS, eight normal (five males and three females) and two affected male fetuses were detected. Absence of methylation in the CVS was observed in two cases, which was not found upon subsequent examination of the newborn or of fetal tissues. In the 50 CVS not ‘at risk’ for fragile X syndrome, abnormal fragment patterns for probe StB12.3 were detected in 32 per cent for female and 24 per cent for male fetuses. This abnormal pattern could be due to absent or partial methylation of the CpG island of the FMR-1 gene in chorionic villus tissues.     

Prevention through design: The effect of European Directives on construction workplace accidents

Workplace accidents still occur with distressing frequency, particularly in construction. Industrialized countries have become increasingly aware of this situation and have adopted policies to attempt to deal with this issue. Such policies have led to the development of new laws and regulations with a view to improving workplace conditions.This paper first analyzes policies regarding accident prevention in the European Union, as initially stipulated in the European Framework Directive 89/391/EEC, and more specifically in Directive 92/57/EEC, on the implementation of minimum safety and health requirements at temporary or mobile construction sites, concentrating on prevention through design. Whilst designers previously had some responsibilities for reducing risk under common law provisions in many countries, this directive was the first explicit legislation to enforce particular duties upon them. The adaptation of the provisions in this directive to the national legislation of EU member countries is also studied.The second section of the paper analyzes the incidence rate of workplace accidents in the construction sector in each country from the year when these regulations came into force until the present time. Based on the evolution of these accident rates, the paper postulates the extent to which European policies have contributed to accident prevention in construction. It is now more than a decade since this legislation has been in force which provides a suitable period for a reflective analysis on it is impact.