Non-radiological contaminants from uranium mining and milling at Ranger, Jabiru, Northern Territory, Australia

Abstract

Protection from the hazards from radioactivity is of prime importance in the management of uranium mine and mill wastes. Such wastes also contain non-radiological contaminants (heavy metals, acids and neutralising agents) which give rise to potential long-term health and environmental hazards and short-term hazards to the aquatic ecosystem, e.g. as a result of release of waste water. This study seeks to identify non-radiological contaminants (elements) transferred to waste water at the Ranger uranium mine/mill complex at Jabiru, which are likely to hazardous to the aquatic environment.The two principal sources of contaminants are: (i) ore and waste rock mobilised from mining; and (ii) process reagents used in the milling and mineral extraction process. These substances may or may not already be present in the natural environment but may lead to deleterious effects on the aquatic environment if increased above threshold levels.Rhenium, derived from the ore body, was found to be significantly enriched in waste water from Ranger, indicating its suitability as an indicator element for water originating from the mining and milling process, but only uranium, likewise derived from the ore, and magnesium, manganese and sulfur (as sulfate) from the milling process were found to be significant environmental contaminants.

The Use of Geochemical Speciation Modelling to Predict the Impact of Uranium to Freshwater Biota

“…The relative proportions of these three uranyl-organic species progressively decline with increasing uranyl concentration, ranging from approximately 83% at background to about 21% at 4 mg 1 1 . In contrast to pH 5, the relative proportions of the hydrolysed uranyl-organic species (i.e.…”

“…Uranium has been identified as the prime ecotoxic contaminant in mine waste waters [1] entering the Magela Creek, downstream of the Ranger Uranium Mine (RUM), Alligator Rivers Region, Northern Australia (12°40'S, 132°57'E) (see Fig. 1 in Brown et al [2]).…”

Potential Hazard of Lanthanides and Lanthanide-Based Nanoparticles to Aquatic Ecosystems: Data Gaps, Challenges and Future Research Needs Derived from Bibliometric Analysis

“…However, the higher levels of Ln have also been reported: sum Ln concentrations in the Syr Darya River ranged from 15.1-28.3 µg/L [118] and concentrations of Ln in stream waters (Eastern Canada) from <5 to 11,540 ng/L, with an average of 253 ng/L (n = 498) [119]. At very polluted sites, Ln concentrations may increase up to 78 µg/L [114,120] and, in exceptional cases, e.g., in acid mine drainage waters or after lake restoration while using Ln-modified bentonite clay, Ln concentrations may even reach 15 mg/L [116,[121][122][123][124][125]. Thus, comparison of the Ln concentration in the surface waters and reported toxicity values allows for concluding that, although even in contaminated waters Ln concentrations are still lower than the reported toxic concentrations for aquatic organisms, in certain cases (e.g., in the treated water bodies or mine waste water) Ln may already disturb normal function of ecosystem.…”

Hydra viridissima (green Hydra) rapidly recovers from multiple magnesium pulse exposures

“…The low toxicity of Mg under most environmental conditions and its role in ameliorating the toxicity of more toxic transition metals has meant that it has rarely been considered a priority environmental toxicant [7]. However, Mg has been identified as a contaminant of concern in mine waters that are discharged from the Ranger Uranium Mine in northern Australia [7][8][9]. Site-specific ecotoxicological testing confirmed that Mg was more toxic than in previous Mg studies in the extremely soft waters surrounding Ranger Mine.…”