Response of antimony and arsenic in karst aquifers and groundwater geochemistry to the influence of mine activities at the world’s largest antimony mine, central China

•Sb concentrations varied with aquifers, whereas As differed seasonally.•Sb and As co-pollution types were identified by cluster analysis.•Mine activities have significant impacts on karst groundwater geochemistry.•Elevated SO42− was related to Sb pollution indicated by tracing sulfate sources.