This study investigates seasonal variation in concentration of some heavy metals in suspended and respirable particulate matter (SPM and RPM) collected from five different zones situated in Kota city during both summer (March, April, May and October) and winter (January, February, November and December) seasons of 2011-2012. Mean concentrations of anthropogenic origin metals (Pb, Zn, Cu and Cd) were higher in winter and lower in summer with their relative abundance in order: Zn > Pb > Cu > Cd while reverse trend was observed for crustal origin metals (Ca, Mg and Fe) at all zones. Meteorological conditions such as temperature, relative humidity, wind velocity and wind direction during winter and summer were found affecting the metals concentration trends in different seasons. Wind roses indicate that the zones lying in predominant North-east wind direction from point source (KSTPS) in winter (25.74%) and summer (15.31%) faced higher metal burden following zone 1, which is suffering most owing to its closest location to the source. Statistical analysis by Pearson's correlations, enrichment factor and principal component analysis indicates that coal based Thermal Power Plant is the major source of heavy metals besides other industrial activities in the study area. It is to be noted that because of higher residence time, significant concentration of Pb is found at all the zones in the city which, probably, has its origin in earlier vehicular exhaust as well.
Aims: Oxidation of p-anisaldehyde by Quinolinium dichromate (QDC) in the aqueous acetic acid medium in the presence of sulphuric acid using surfactants. Background: The oxidation studies of anisaldehyde is very important as the oxidized products are used as a synthetic intermediate for the preparation of a variety of drugs. Quinolinium dichromate (QDC) has emerged as a very useful and versatile oxidant. Micellar medium enhances the reaction rate. Objective: 1. To study the kinetics of the reaction, which includes the determination of order, rate, and activation parameters. 2. Spectral characterization of QDC by NMR and the kinetic study of the reaction mechanism is done through UV – A visible spectrophotometer. 3. Solvent effect for the oxidation of anisaldehyde by QDC. 4. Determination of critical micelle concentration (CMC) of used surfactants (CTAB and SDS). Methods: The reactions were followed at constant temperature and were followed by monitoring the UV – Visible spectrophotometer (Double Beam – 2203) in a quartz cuvette of 1 cm path length by following the absorbance decay of Cr (VI) at 440 nm Result: KINETIC RESULTS: 1. The reaction follows first-order dependence on p-anisaldehyde and QDC. 2. The reaction is found to be acid-catalysed. A plot of log [k] versus log [H+] was found to be a straight line with a slope of 1.07. EFFECT OF SOLVENT: The rate of reaction increases with the increase in acetic acid proportion in the medium, which suggests that the reactions were of the ion–dipole type. MICELLAR EFFECT: 1. Experimental results demonstrated that anionic surfactant SDS catalysed and accelerated the study more effectively than CTAB, which is a cationic surfactant, and the rate of reaction increases with an increase in the concentration of the SDS while in the case of CTAB, the rate decreases with an increase in its concentration. 2. CMC values of CTAB and SDS were 3.9 mM and 8.2 mM, respectively. Conclusion: The value of negative ΔS (entropy of activation) and positive ΔH (enthalpy of activation) suggests the formation of more ordered activated complexes, and the transition state is highly solvated. SPECTROSCOPIC ANALYSIS 1.NMR characterisation of synthesised QDC shows a resemblance with pure QDC. 2. Effect of oxidant QDC, p-anisaldehyde and acid was studied by considering the spectra of the reaction mixture and varying their concentration.
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