title: Rock magnetic finger-printing of soil from a coal-fired thermal power plant.
abstract: We present seasonal rock magnetic data for 48 surficial soil samples collected seasonally around a coal-fired thermal power plant on the southwest coast of India to demonstrate how fly ash from the power plant is transported both spatially and seasonally. Sampling was carried out during pre-monsoon (March), early-monsoon (June), monsoon (September) and post-monsoon (December) seasons. Low- and high-frequency magnetic susceptibility (χlf and χhf), frequency-dependent magnetic susceptibility (χfd), χfd %, isothermal remanent magnetization (IRM), "hard" IRM (HIRM), saturation IRM (SIRM) and inter-parametric ratios were determined for the samples. Scanning electron microscopy (SEM) was used on limited number of samples. NOAA HYSPLIT MODEL backward trajectory analysis and principal component analysis were carried out on the data. Fly ash samples exhibit an average HIRM value (400.07 × 10(-5) Am(2) kg(-1)) that is comparable to that of soil samples. The pre- and post-monsoon samples show a consistent reduction in the concentration of magnetically "hard" minerals with increasing distance from the power plant. These data suggest that fly ash has indeed been transported from the power plant to the sampling locations. Hence, HIRM may perhaps be used as a proxy for tracking fly ash from coal-fired thermal power plants. Seasonal data show that the distribution of fly ash to the surrounding areas is minimum during monsoons. They also point to the dominance of SP magnetite in early-monsoon season, whereas magnetic depletion is documented in the monsoon season. This seasonal difference is attributable to both pedogenesis and anthropogenic activity i.e. operation of the thermal power plant.
authors.affiliation: Department of Civil Engineering, Manipal Institute of Technology, Manipal University, Manipal, 576104, India.
authors.forename: Minal
authors.initials: M
authors.lastname: Gune
authors.affiliation: Department of Civil Engineering, Manipal University, Jaipur, 303007, India.
authors.forename: B G
authors.initials: BG
authors.lastname: Harshavardhana
authors.affiliation: Department of Civil Engineering, Manipal Institute of Technology, Manipal University, Manipal, 576104, India. k.balakrishna@manipal.edu.
authors.forename: K
authors.initials: K
authors.lastname: Balakrishna
authors.affiliation: Department of Civil Engineering, Manipal Institute of Technology, Manipal University, Manipal, 576104, India.
authors.forename: H N
authors.initials: HN
authors.lastname: Udayashankar
authors.affiliation: Department of Marine Geology, Mangalore University, Mangalagangothri, 574199, India.
authors.forename: R
authors.initials: R
authors.lastname: Shankar
authors.affiliation: Department of Marine Geology, Mangalore University, Mangalagangothri, 574199, India.
authors.forename: B R
authors.initials: BR
authors.lastname: Manjunatha
mesh_terms: D003031:Coal; D060729:Coal Ash / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods*; D007194:India; D008280:Magnetics; D011210:Power Plants; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D003031:Coal; D060729:Coal Ash; D012987:Soil; D012989:Soil Pollutants
keywords: Backward trajectory; Hard isothermal remanent magnetisation; Principal component analysis; Rock magnetic studies; Soil pollution; Southwest coast of India; Surface soil; Thermal power plant