Geochemical insights and model optimisation for pilot-scale passive treatment of manganese and zinc in a legacy mine in Japan.

Elevated concentrations of manganese (Mn) and zinc (Zn) in water bodies can disrupt ecosystems and damage aquatic life. However, the mechanisms underlying the removal of Mn and Zn under dynamic conditions and the optimal hydraulic retention time (HRT) for passive treatment plants remain unclear. Here, a pilot-scale passive treatment system for the removal of Mn and Zn from legacy mine drainage in northern Japan is proposed; it was performed at circumneutral pH for 152 days.

Assessment of seasonal changes in groundwater quality of waste rock dump in temperate continental climate, northern Japan.

Understanding seasonal groundwater quality changes in temperate continental climate waste rock dumps (WRDs) is necessary for sustainable environmental risk prevention and legacy mine contamination management. Therefore, we conducted a field investigation of a WRD to determine the mechanisms controlling its groundwater quality dynamics. The research aimed to understand the impact of seasonal changes on heavy metals released from the WRD.

Seasonal effects of natural attenuation on drainage contamination from artisanal gold mining, Cambodia: Implication for passive treatment.

In Mondulkiri province, Cambodia, artisanal gold miners dump tailings and wastewater from gold processing into a tributary of the Prek Te River. In the rainy season, heavy metal concentrations in the tributary decrease below the WHO drinking water standard levels through natural attenuation; however, this does not occur in the dry season. To further understand the natural attenuation mechanism, detailed analyses of the wastewater from tailing and tributary water, tributary sediments, waste rock, and ore minerals were undertaken in both seasons.