Characterization Of Organic Constituents Research Articles

Characterization and quantification of persistent organic pollutants in fly ash from coal fueled thermal power stations in India

The burning of pulverized coal to produce energy for generation of electricity in thermal power plants results in huge quantity of coal ash of varying properties. In India the coal based thermal power plants have been the major source of power generation in the past and would continue for decades to come. Because of the increase in electricity production, the amount of ash produced will increase proportionally. Very few studies on characterization of organic constituents in fly ash from Indian thermal power plants have been reported in the literature. In the present study, the fly ashes generated from five thermal power stations from different parts of India were investigated regarding the elaboration of distribution pattern of persistent organic pollutants (POPs) such as PAHs and PCBs in them. The PAHs in the fly ash samples were identified and quantified using high pressure liquid chromatography (HPLC-UV) whereas the estimation of PCB congeners was carried out using gas chromatography (GC-ECD). Lower molecular weight (MW) PAHs, were found to be predominant in fly ash samples. The concentration of Benzo(a)Pyrene which is the most potent carcinogenic PAH, varied between 0.82 ng/g and 18.14 ng/g with a mean concentration of 9.02 ng/g. Among the PCB congeners, CB-77 is having higher toxicity value, the concentrations of which in the fly ash samples were in the range of 4.58 ng/g to 104.98 ng/g with a mean value of 62.53 ng/g.

Characterization of Organic Constituents in Aerosols in Relation to Their rigin and Transport: A Review

Abstract Organic matter in aerosols is derived from two major sources and is admixed depending on the geographic area. These sources are biogenic detritus (e.g. plant wax, microbes, etc.) and anthropogenic emissions (e.g. oils, soot, etc.). Both biogenic detritus and some of the anthropogenic emissions contain organic materials (C14- C40 +) extractable by solvent, which have unique and distinguishable compound distribution patterns. Molecular composition analysis has been applied to such extracts after suitable chemical separation into subfractions (i.e. hydrocarbons, ketones, fatty acids, fatty alcohols, and wax esters). Microbial and vascular plant lipids are the dominant biogenic residues and petroleum hydrocarbons, with lesser amounts of the pyrogenic polynuclear aromatic hydrocarbons (PAH), are the major anthropogenic residues. These lipid fractions are quantified and characterized in terms of their contents of both homologous compound series and specific molecular markers. Samples from rural sites c...