Polycyclic Aromatic Hydrocarbons (PAHs) Pollution Generated from Coal-Fired Thermal Power Plants: Formation Mechanism, Characterization, and Profiling

Abstract

Coal can turn out to be more vital as an energy source in the present century, and coal includes substantial amounts of organic and inorganic matter. At the point when coal burns, chemical and physical transformations take place, and numerous harmful mixes are shaped and excreted. The combustion of pulverized coal to produce electrical energy in thermal power plants results in large quantities of coal ash with varying properties. Coal ashes (Bottom ash and Fly ash) are post-combustion particulate residue. It contains various inorganic and organic compounds and some of which have already been identified as pollutants like mercury and polycyclic aromatic hydrocarbons (PAHs). Environmental contamination by PAHs has become one of the major concern across the globe. Huge amount of coal ash is being dumped at deposition sites nearby the power plant, which can contaminate the soil by its comparatively high PAH contains. PAHs contain reactive metabolites like epoxides and dihydrodiols which have the potential to bind with proteins and DNA, resulting in tumors and cancer via biochemical disruption and cell damage. The organic structure of coal generally composed of two complementary parts. The major component consists of ether or thioether linked insoluble and macromolecular networks of fused aromatic and hydroaromatic moiety. The recessive component is soluble in organic solvents. This molecular state involves aliphatic hydrocarbons, PAH, hydroxylated PAH, and heterocyclic compounds. Incomplete coal combustion is regarded as an important factor leading to the formation of PAHs. It is recommended that the development mechanisms of PAHs will be an undeniably imperative point for specialists to discover techniques for controlling emanations amid coal ignition. In the current chapter, formation mechanism of coal and hydrocarbons, uses of coal, generation of PAHs during coal combustion, and harmful effects of PAHs to environment and human are discussed. Towards the end, recent findings on the characterization and PAHs profiling in coal ash have been described.