Industrial wastewater, rich in heavy metals, and sulfate, necessitates efficient removal disposal. Traditional methods like chemical precipitation and membrane filtration are costly and inefficient, especially at lower metal concentrations. Sulfate reduction by sulfate-reducing bacteria (SRB) offers a promising alternative, requiring electron donors such as glucose or ethanol to facilitate metal removal utilizing anaerobic sludge biomass, with syngas (H2, CO2, and CO) serving as an alternative carbon and energy source. Experimental investigations were conducted at varying copper concentrations, spanning low (10 mg/L) to high (50 mg/L) levels, which showed very high promising results, with sulfate reduction efficiency 100% at copper concentrations below 10 mg/L and 80% at 50 mg/L. The bioprecipitate analysis further confirmed the presence of insoluble CuS, highlighting the potential of this method for treating heavy metal-containing, sulfate-rich wastewaters by using syngas as the substrate. However, the impact of various process parameters, such as syngas compositions, sulfate concentration, on Cu removal via sulfate reduction utilizing CO as the sole energy and carbon source, has not been thoroughly investigated, which are of considerable implications in the efficient treatment of heavy metal-containing sulfate-rich wastewaters and for keeping the economics of the treatment process low.