You may try Phytoremediation ...

You may try Phytoremediation methods,

First run the waste water through PH stablisation tanks.

Next run this over a bioswale trench using concrete or HDPE liners to prevent leaching.

There should be about 1000 mm gravel base and about 300-500 mm rootzone.

Collect the treated wastewater and run the same in another bioswale.

Repeat the treatment in third and fourth bioswale.

You may use locally available fast growing plants that have fibrous roots and some tubers.

Collect all the biomass and send it to a biogas chamber.

Collect the sludge and incinerate.

You shall be able to collect most of the metal lost and prevent the enviornmental damage.

Hope you have the land and workforce available at low cost in your area.