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Most coal in India originates from the Korb basin (Chhattisgarh), where coal mines, thermal power, and aluminum plants operate. Groundwater in this region faces severe pollution due to land reclamation, leaching of coal‐related contaminants, waste disposal, and industrial effluent seepage. This work presents results from monitoring groundwater pollution in the Korba basin from 2012 to 2017. Fluoride, aluminum, manganese, and iron levels exceeded acceptable quality limits across all 28 studied locations, with excessive nitrate, magnesium, calcium, and lead levels in specific sites. Tracking seasonal and temporal fluctuations in the most polluted site, namely Kudurmal, revealed peak solute concentrations during the monsoon period and a sustained 18% increase during the study period. Factorial analysis suggests groundwater contamination arises from both human activities and natural sources. These findings underscore the urgent necessity of devising remediation strategies for the drinking water supply. [ABSTRACT FROM AUTHOR]

Several million tons of coal are extracted which discharge the contaminated mineral water into the environment in the coal mines located in the Korba basin (Chhattisgarh, India) chosen as the study area. The aim of this work is to describe: (i) the physico‐chemical characteristics (pH, EC, TDS, DO, RP, CC (carbonate carbon), OC (organic carbon) F−, Cl−, NO3−, SO42−, SiO44−, PO43−, Na+, K+, Mg2+, Ca2+, Al, As, Sb, Fe, Mn, Zn, Cd, Pb, and Hg) of the coal mine water samples, (ii) spatial, seasonal (i.e. PrM (pre‐monsoon), M (monsoon) and PtM (post monsoon) and temporal (over the period of 2012–2017) variations, (iii) sources of contaminants from fourteen coal mines, (iv) suitability of the water for drinking and other uses, and (v) health impact of the mine water in view of developing remedial approaches. The mine water is neutral in nature with high TDS (total dissolved solid) values ranging from 620 to 13711 mg L−1 due to mainly high carbon content. The concertation of all species lies between 519–11432 mg L−1 with maximum value of OC. The most dominating species were OC, CC, Cl−, NO3−, SO42−, Na, and Ca. Species, that is, F−, OC, Al, Fe, As, Sb, Cd, Pb, and Hg occurred beyond their limits. Their higher concentration in the PtM is observed. Water quality index (WQI) values ranged from 17.52 to 95.68 in the PtM period. 42.85%, 21.42%, and 7.14% of water samples represent "excellent water", "good water" and "poor water" respectively in the PtM period. In addition, the fertilizer and trace element concentrations in the water samples were compared with the limit values determined for usability as drinking water. Accordingly, it was concluded that it is not suitable for use as drinking water in terms of TDS, F−, and NO3− concentrations. In addition, AsT (total arsenic), F− and NO3− pollutants were detected in the water samples, and it was observed that F− and NO3− ions did not have a carcinogenic effect. A health risk assessment of As has been made, and it is found that adults and children have a low risk of developing cancer from the exposure. However, arsenic has high non‐carcinogenic and potentially harmful effects. [ABSTRACT FROM AUTHOR]

In this work, microscopic X-ray absorption near-edge structure spectroscopy ([mu]-XANES) and confocal microscopic X-ray fluorescence analysis ([mu]-XRF) were used for the in vivo determination of the distribution of total selenium and for the local speciation of selenium in roots and leaves of onion. Selected Allium cepa L. plants were grown hydroponically in a standard medium containing inorganic selenium compounds (selenite or selenate). The measurements were performed in vivo, that is, on living plants without the need for any form of sampling or sample pretreatment and without the necessity for cutting plant tissues into pieces. Distinct energy differences of the XANES spectra of various selenium reference compounds having different oxidation states allow adjusting the excitation energies used for [mu]-XRF mapping in such a manner that the distribution of selenium in various oxidation states is obtained with a spatial resolution of a few tens of micrometers within the virtual cross section of the onion tissues. We find that the ratio of inorganic to amino acid selenium compounds differs in various subparts of the plant. Detailed in vivo investigation of the distribution of various selenium species in virtual cross sections of root tips and green leaf shows that the selenium transport takes place via different mechanisms, depending on the nature of the selenium compounds originally taken up.

In areas of contrasting geology, local but significant spatial changes in environmental conditions can occur suddenly and unexpectedly within aquifers, hampering accurate assessment of groundwater chemistry. Recently, the rare earth elements (REEs) have become extensively used in identifying geochemical processes in aqueous systems, due to their unique sensitivity to environmental changes. In this study, the REEs and Y (yttrium), combined with the chemical parameters of the main, minor and trace water components, and with the isotopic signatures of δ18O-H 2 O, δ2H-H 2 O, 3H-H 2 O, δ34S-SO 4 , δ18O-SO 4 , were investigated in order to gain a better understanding of the geochemistry of the groundwaters in the Holy Cross Mountains, which possesses a diverse hydrogeological system. The waters studied are 'young', meteoric-derived, of acidic to slightly alkaline pH (4.95–7.75) and TDS values of 38.97–2713.91 mg/L. They represent predominantly the HCO 3 -Ca-Mg and less often the HCO 3 -Ca-SO 4 -(Mg) or SO 4 -Ca-(Mg) types. The dissolved (<0.45 μm) concentrations of the REEs (5.55 to 13,857.35 ng/L) and Y (4.43 to 2450.22 ng/L) in the waters studied are the result of host rock dissolution, and tend to increase significantly, by up to several orders of magnitude, via interactions between the rocks and acidic waters. Speciation calculation reveals that dissolved REE + Y in neutral and alkaline waters are transported mainly as bicarbonate (CO 3) 2 − and carbonate CO 3 + complexes, while in a more acidic environment these elements occur preferably as free ions (REE3++Y3+), and their abundance gradually increases along with decreasing pH value. The EUS (European Shale) normalized REE patterns of the waters studied show two distinct dominant types: (i) upwards-sloping with HREE-enrichment (LREEsHREEs). The first pattern type reflects REE fractionation in alkaline and oxygenated waters, leading to preferential LREE adsorption onto mineral particles, accompanied by complexation of HREEs with carbonate and bicarbonate ions, while the second pattern type results from dissolution of the host rocks in more acidic conditions. The REE patterns in the waters studied are mostly different from the REE patterns characteristic of the host rocks, except for some water samples from carbonate aquifers. Ce and Eu anomalies were recorded in the waters studied. Some of the negative Ce and positive Eu anomalies were inherited from host rock dissolution, while other negative or positive Ce anomalies reflect oxygenic or more reducing conditions, respectively. • REE patterns in the waters generally do not correspond to patterns of their host rocks. • The waters show mostly LREEsHREEs REE patterns. • REE content depends on the type of the dissolved host rocks and pH of interacting water. • Ce and Eu anomalies are inherited from the rocks or develop in specific Eh conditions. • Tracking REE + Y behavior supports the assessment of geochemical processes in aquifers. [ABSTRACT FROM AUTHOR]