Scholars@Duke
Robert Hill

Selected Publications

The Water Quality Impacts of Legacy Hard-Rock Lithium Mining and Processing.

Journal Article Environmental science & technology · December 2025 Hard-rock Li mining from Li-pegmatites is rapidly expanding to support the clean energy transition, yet associated water-quality impacts remain understudied. Here, we evaluate surface water and groundwater in the Tin-Spodumene Belt (TSB), a legacy Li minin ... Full text Cite

Radionuclides and the uranium isotope fingerprint of globally produced phosphate rocks, mineral fertilizers, and phosphogypsum waste and its potential effect on the environment.

Journal Article Journal of hazardous materials · November 2025 The occurrence of uranium (U), thorium (Th), and radium (Ra) in phosphate rocks (PRs) leads to enrichment of these radionuclides in produced fertilizers and phosphogypsum waste byproducts. This study presents a global dataset of U- and Th- series radionucl ... Full text Cite

Impacts of fertilization on metal(loid) transfer from soil to wheat in a long-term fertilization experiment - using <sup>87</sup>Sr/<sup>86</sup>Sr isotopes as metal(loid) tracer.

Journal Article Environment international · November 2025 Fertilizers are widely used to sustain food production but can alter soil chemistry and potentially contribute toxic metal(loid)s to agricultural systems. For the first time, this study examined the occurrence of select metal(loid)s (Zn, Sr, V, As, Cd, Pb, ... Full text Cite

Role of coal ash morphology and composition in delivery and transport of trace metals in the aquatic environment.

Journal Article Environmental pollution (Barking, Essex : 1987) · December 2024 Fly ash is predominately the inorganic byproduct of coal combustion for electrical power generation. It is composed of aluminosilicates with Fe, Mg, K, and Ca forming submicron to 100 μm spheres and amorphous particles. During combustion trace elements are ... Full text Cite

The potential water quality impacts of hard-rock lithium mining: Insights from a legacy pegmatite mine in North Carolina, USA.

Journal Article The Science of the total environment · December 2024 The global green energy transition has spurred increased lithium exploration and extraction, yet the water quality impacts from lithium mining are understudied. This study investigates the potential water quality impacts from a legacy hard-rock lithium min ... Full text Cite

Reconstructing the depositional environment and diagenetic modification of global phosphate deposits through integration of uranium and strontium isotopes

Journal Article Chemical Geology · September 5, 2024 The geochemistry of phosphate rocks can provide valuable information on their depositional environment and the redox condition of global oceans through time. Here we examine trace metal concentrations and uranium (δ238U, δ234U) and st ... Full text Cite

Tracing the Environmental Effects of Mineral Fertilizer Application with Trace Elements and Strontium Isotope Variations

Journal Article Environmental Science and Technology Letters · June 11, 2024 Fertilizer utilization is critical for food security. This study examines the occurrence of trace elements (TEs) and Sr isotope (87Sr/86Sr) variations in phosphate rocks and mineral fertilizers from a sample collection representative ... Full text Cite

Lead isotopes and rare earth elements geochemistry of global phosphate rocks: Insights into depositional conditions and environmental tracing

Journal Article Chemical Geology · November 20, 2023 Phosphate rock bears both geologically and environmentally significant information. Rare earth elements and yttrium (i.e., REY) characteristics have been commonly used for reconstructing the redox conditions of depositional environments and the effects of ... Full text Cite

The strontium isotope fingerprint of phosphate rocks mining.

Journal Article The Science of the total environment · December 2022 High concentrations of metal(loid)s in phosphate rocks and wastewater associated with phosphate mining and fertilizer production operations pose potential contamination risks to water resources. Here, we propose using Sr isotopes as a tracer to determine p ... Full text Open Access Cite