Can Floating Wetlands purify rivers contaminated by mining?

I was fascinated by the innovation of using man-made floating wetlands to clean & purify surface water bodies that are victims of sewage pollution.

As a Mineral Resource Governance & Environmental Justice Activist I have worked with rural communities whose sources of water e.g dams, rivers have been polluted by the corporate mining activities in their area and this has led to livestock dying and humans falling sick after bathing or drinking the water.

These areas are producers of gold, diamond, coal and granite. So my question is can the Floating Wetlands also manage to purify and remove toxins deposited into the rivers and dams as a result of gold, diamond and coal mining?