Kun Qian

TL;DR: Speciation analysis and geochemical modeling results indicate that fluoride complexes in groundwater are dominated by free fluoride, the negative charge of which favors fluoride enrichment in groundwater under basic conditions, and iodide, iodate and organic iodine co-occur in groundwater at NCP with iodide as the dominant species.

TL;DR: High fluoride groundwater was mainly distributed in the central plain and coastal area of the NCP, and characterized by the Na-HCO3 or Na-Cl type water, lower Ca and higher TDS concentrations, including cation exchange between Ca and Na on the surface of clay minerals.

TL;DR: PAHs might have posed a major threat to the quality of potable groundwater in Guozhuang karst water system through leakage of contaminated surface water and/or infiltration of PAH-containing precipitation.

TL;DR: The results of this study suggest that the compaction of clayey sediments can be a major hydrogeological process controlling the genesis of high iodine groundwater in deep aquifers at NCP.

TL;DR: Fluorescence analysis showed sediment and groundwater OM are dominated by oxidized and reduced quinone-like compounds; shorter emission wavelengths observed in groundwater indicated more labile and protein-like organic substances than in sediments, and demonstrated more bioavailable OM occurs in groundwater and that labile OM degradation promotes As release.