Potential Groundwater Pollution Risks by Heavy Metals from Agricultural Soil in Songon Area(Abidjan,Cote d’Ivoire)

The soil samples were collected taking into account the land use in Songon area. The hydraulic conductivity (K) of soils was characterized in-situ when specific yield (Sy), pHw and concentrations of Cooper, Iron, Zinc, Cadmium, Chromium and Lead were measured in the laboratory. Pollution load indices (PLI) were calculated to evaluate the soil contamination levels. The soils were neutral and alkaline (6.7≤ pH ≤ 9.20), permeable (1.9 í 10-5?m·s-1?≤ K ≤ 8.2 í 10-4?m·s-1), with a high specific yield (13.33% ≤ Sy ≤ 33.33%) which can favor the pollutants transfer. The heavy metals (Fe, Cu, Zn, Cd, Cr and Pb) have very high concentrations in soils. The integrated pollution indices (PLI) indicate that almost 70% of Songon soils are moderately contaminated by the investigated heavy metals, with windows presenting high indices of pollution related to the intensive use of fertilizers and pesticides. The establishment of new boreholes in the Songon area should consider these heavy metals, so as to avoid the risk of groundwater pollution due to the physical properties of soils.

Assessment of Impacts and Risks of Air Pollution Applying Two Strategies of Numerical Chemistry Transport Modelling

Assessment of harmful impacts and risks of air pollution in case of accidents as well as of long lasting exposition is an important challenge of chemical transport modeling. Sad confirmation of this statement unexpectedly has come from the nuclear power plant accident in Fukushima which occurred while this paper was finalized. Two strategies to comply with the task of impact and risk assessment in extended regions like Central Europe or the Balkans are described. The first one is characterized by application of a single model system to an extended domain. The other one is based on the combined application of several chemical transport models designed for the use in various sub-domains in the region under consideration. Advantages and disadvantages exist for both approaches. For instance, the single model strategy allows unified and harmonized assessment of risks in a larger region, whereas the combined model strategy may pro-vide faster and locally more specific response in emergency cases. The single model approach is treated exploiting applications of the EURAD model system. The combined model approach is a novel way of joint use of chemical transport model systems developed for the Balkans. The models are described and the accuracy of simulations carried out with them is briefly demonstrated by comparison of simulated and observed concentrations of air pollutants. Applications regarding the search of sources for high pollution events and the assessment of risks through known sources are exem-plarily discussed.

Crystallization from Thin Films on a Hot Plate: A New Approach of Solid Surface Pattering

The sacrificial polymeric template usually used in lithographic methods could be replaced by crystalline materials such as ionic salts which, in some special conditions, can form arrays of single crystals. Atomic force microscopy investigations performed on such samples show their regularity and nanometric thickness. They can serve as a part of an ionic/molecular crystal grid or as mask in crystal lithography. Alternating the polarity degree of the employed solvents/dispersing media by matching materials qualities, we fabricated a sodium chromate and sulphur crystalline net, iron oxide nanoparticle grid and a sulphur single crystal array. The lack of any expensive/sophisticated technology in the production process of final devices makes this approach attractive.

The Influence of Gravity on Single Crystallization in Large Volume Drops

The chemical, physical, and biological properties of more than two millions of proteins which follow to be synthesized by Pharmaceutical Industry, can be anticipated (by using their XRD diffrac-tograms) if they will be grown from aqueous drops as high quality, large volume single-crystals. This is not a simple task and usually the growing process is seen as art rather than a science. The growing is expensive, time consuming, and finally an amorphous aggregate may result instead one single-crystal. In this article, we show for the first time how one single crystal can be grown in large volume hanging drops through their fast evaporation. The single nucleation is determined by choosing the proper sense of gravitational force relative to the drop triple line contact. In a special configuration, single-crystals of glycine and threonine were rapidly grown.

Study of the Hydro-Chemical and Bacteriological Well Water Characteristics of M’Bahiakro (Central-Eastern Cote d’Ivoire)

The use of well water by disadvantaged populations in most African cities often presents health risks. The purpose of this study is to determine the physico-chemical and microbiological quality of M’bahiakro well water. A series of physico-chemical, microbiological and piezometric analyses were carried out on the well water in the area. The results of these analyses were processed using Piper and Schoeller-Berkaloff diagrams and the software R 3.1.2 for Principal Component Analysis. Physico-chemical analysis results show that the water has an average temperature of 28&#176C. They are acidic, with a pH that generally varies from 4 to 6. M’bahiakro well waters are highly mineralized, with an average electrical conductivity of 369.1 μS/cm and 984.1 μS/cm and pass from sodium and potassium chlorinated facies in the dry season (February) to sodium chlorinated facies in the rainy season (October) with K+, Na+ and NO3- ions dominating. These ions would be the result of soil rainfall and the intervention of anthropogenic activities in the pollution of shallow groundwater. Bacteriological results exploitation shows that the well waters studied host high densities of enteritis bacteria (E. coli, Fecal streptococcus, and Clostridium perfringens) during the rainy period (October). M’Bahiakro’s well water is of poor quality and unsuitable for human consumption without prior treatment. However, they deserve particular attention and would require further treatment in rainy periods.