(1) An acid mine drainage (AMD) source with a flow rate of 30 m³/h contains metal concentrations as shown in the table below. The AMD also contains 1650 mg/L of sulfate. Available additives are lime (at $150/ton) and ethanol (at $200/m³ and 70% purity).

It is planned to build a bioreactor capable of reducing sulfate in the presence of an electron donor for the purpose of forming metal sulfides that can be subsequently precipitated (in a tank downstream) for recovery. The stream leaving the bioreactor to the precipitation tank is at a pH of 7.5.

a) Determine what percent of the total metals present in the AMD can be removed by precipitation as metal sulfides.