Modeling Water Pollution under Different Scenarios of Zinc Load on the Nizhnekamskoe Reservoir Watershed

The potentialities of the physically-based model ECOMAG-HM for the study of zinc content formation regularities in the Nizhnekamskoe Reservoir basin have been demonstrated. The basin is characterized by high concentrations of heavy metals in natural waters due to the significant content of ore-forming elements in rocks and a high level of economic development. The daily zinc concentrations have been calculated, and the maps of mean annual zinc concentrations in the river network have been compiled. Local areas of the catchment not covered by hydrochemical observations and showing a significant level of river water contamination by zinc have been identified. The fields of the genetic components of zinc hydrochemical runoff have been calculated. The contribution of anthropogenic sources to the zinc runoff formation has been estimated, and it has been established that, with the current level of anthropogenic load, the contribution of wastewater point discharges does not exceed 4%. The scenarios and consequences of increasing the amount of zinc discharged as part of wastewater are considered. The time scale of the catchment self-purification from zinc has been evaluated. The results show that, in the absence of external impacts on the catchment area, a decrease in zinc content in river waters over a 400-year period will be about as little as 8%.