சுற்றுச்சூழல் பகுப்பாய்வு வேதியியல் இதழ்

This paper presents the findings of a study on adsorption of poly chlorinated biphenyl (PCBs) nano-alumina. PCBs are of significant concern due their high toxicity and long environmental half-lives. Experiments were conducted using batch adsorption procedures at different PCBs concentrations, from 10 to 60 mg/L. The amounts of nano-alumina used were 0.25%, 0.50%, 0.75%, 1%, 2% and 10%. The adsorption of PCBs solution onto the nano-alumina was characterized by an initial rapid adsorption which eventually became constant within 17 hours. Results of this study indicated that nano-alumina was a good adsorbent material for PCB in this study. While at 10% of nano-alumina 54% PCB were removed by nano-alumina. The effect of pH and temperature were also investigated. The Freundlich isotherm adsorption and Langmuir isotherm adsorption were used to analysis the result of the study.

An upsurge in worldwide essential oil sales seems to have intensified corrupt practices by unscrupulous costcutters and adulterators with varying levels of expertise. From outright misrepresentation of botanical species to the addition of cheaper oils to create additional profit for the oil producer, adulteration is unfortunately a common place occurrence in essential oil trade. The most adulterated essential oils fall into two categories: high-value oils like sandalwood and rose and the bestselling oils such as lavender, peppermint, citrus oils, wintergreen, oregano, and thyme. While some adulterations can be detected simply by routine GC-MS testing, with technology such as GC-IRMS and SNIF-NMR, analysts are able to spot adulteration with synthetic compounds or the natural compounds and/or oil fractions taken from cheaper essential oils. Today’s cutting-edge technology for essential oil adulteration detection encompasses many analytical techniques from HPLC and fast GC to GC × GC, IRMS to MS, 1H, and 13C NMR. This paper is a review of 30 studies dating up to May 2014 that detail the analytical procedures used to uncover essential oil adulteration in order to ensure that essential oils are authentic and genuine.

This study investigated the Concentrations of the toxic metals Pb, As, Cr, Zn, Fe, and Cu in soils and plants in Dareta gold mining village, Zamfara State, Nigeria Samples were collected and analysed following standard Laboratory methods. The values obtained were compared with nearby unpolluted area as control. All the soils indicated contamination with the toxic metals Pb, As, Cr, Zn and Cu, above the maximum allowed limits. With the exception of Cd and Ni which were not detected. Cr has the highest Concentration in both Samples indicative of possible mineral deposit in the area. Proper mining regulations and monitoring could help control further contamination.

Adsorption of methyl orange (MO) using an c montmorillonite has been investigated. Which was used for the first time like an adsorbent for removing anionic dye from aqueous solution, the influences of several parameters such as contact time, adsorbent dose, pH and temperature on the adsorption of methyl orange have been tested. The results showed that nearly 40 min of contact time are found to be sufficient for the adsorption to reach equilibrium. The residual concentration of the dye is determined using UV/Vis Spectrophotometer at wavelength 464 nm. Langmuir and Freundlich isotherm models were used to describe adsorption data. Adsorption kinetics was best described by the pseudo-second order model.

In Europe, industry, and especially the surface treatment and finishing sector considered as one of the major polluters, must continue to reduce pollution outflow from their plants in accordance with the water framework directive (WFD 2000/60/EC). In this paper, we proposed to modify a wastewater treatment plant (WWTP) of a company powder coating on aluminium with the aim to reduce the pollutant flux. The different reactions used for the treatment of the metals and anions were studied: First, we conducted laboratory tests, which, once approved by the company, were then transposed to the industrial scale. We describe the results in terms of chemical abatement after modification. In addition, to compare and to evaluate the toxicity of the effluents before and after modification, two ecotoxicological tests were performed. Overall, a technical-economic study confirmed the utility of the chemical modifications carried out.

The present paper offers a review of recent work on synthesis, in situ , and applications of few metal hexacyanoferrate nanoparticles with the general formula M4[Fe(CN)6].xH2O where M is transition metal. Five such metal hexacyanoferrates (MHCF’s) compounds derived from Co, Zn, Fe, Cu and Ni with general introduction followed by synthesis, properties and applications of individual hexacyanoferrate nanoparticles have been featured in this article. In addition, the characterization of aforesaid nanoparticles using instrumental techniques like SEM, TEM and XRD have also been discussed.

Continuous changes in production techniques of composites have attracted the attention of researchers in the various branches of science, starting from academic research and ending in engineered materials. These techniques aim to preserve their beneficial properties and try to increase their efficiency with the introduction of new standards to this component which may not be already owned or efficient in a few capacities and are intended to be introduced to the composites [1]. One of the most important properties is produces nanomaterials along with the improvement of its physiochemical properties, due to the unique importance in the technology of its applications [2]. TiO2 is a common semiconductor material that is used in this way due to many causes such as it being inexpensive, and nontoxic [3], and its relatively high reactivity and chemical stability under ultraviolet light [4].