『Abstract
Ion chemistry of mine pit lake water reveals dominance of alkaline
earths (Ca2+ and Mg2+) over total cation
strength, while SO42- and Cl-
constitute the majority of total anion load. Higher value of Ca2+
+ Mg2+/Na+ + K+ (pre-monsoon
5.986, monsoon 8.866, post-monsoon 7.09) and Ca2+ +
Mg 2+/HCO3- + SO42- (pre-monsoon 7.14, monsoon 9.57,
post-monsoon 8.29) is explained by weathering of Ca-Mg silicates
and dissolution of Ca2+-bearing minerals present in
parent rocks and overburden materials. Silicate weathering supposed
to be the major geological contributor, in contrast to bicarbonate
weathering dies a little. Distribution coefficient for dissolved
metals and sorbed to surface sediments us in the order of Cd＞Pb＞Fe＞Zn＞Cu＞Cr＞Mn.
Speciation study of monitored metals in surface sediments shows
that Fe and Mn are dominantly fractionated in exchangeable-acid
reducible form, whereas rest of the metals (Cr, Pb, Cd, Zn, and
Cu) mostly in residual form. Cd, Pb, and Zn show relatively higher
recalcitrant factor that indicates their higher retention in lake
sediments. Factor loading of monitored physico-chemical parameters
resembles contribution/influences from geological weathering,
anthropogenic inputs as well as natural temporal factors. Ionic
load/strength of lake water accounted for geochemical process
and natural factors, while pollutant load (viz BOD, COD and metals,
etc) is associated with anthropogenic inputs through industrial
discharge.
Keywords: Ion chemistry; Distribution coefficient (Kd);
Metal speciation; Factor analysis』
Introduction
Regional geology and geomorphology of Raniganj coal field area
Methodology
Sample collection and analytical processes
Statistical analysis and quality control
Results and discussion
Hydro-chemical assessment of pit lake water
Geochemical weathering
Anthropogenic contribution/influence
Metal concentrations and partitioning in water sediments of pit
lake
Speciation of metals and their retention in shallow pit lake
sediments
Conclusion
Acknowledgments
References