Reduction of Metal Contents in Coal Stockpile Wastewater Using Electrocoagulation

Abstract

Stockpile wastewater consisted of ferrous metal, manganese metal and total suspended solid (TSS). In addition, it also has high acidity (pH) which is possibly harmful to the environment. This research objectives were to reduce ferrous and manganese metal in coal stockpile wastewater using electrocoagulation technique using aluminum electrode with variation in electrics current and processing time. The most effective conditions in reducing ferrous and manganese concentrations with electric current of ± 2.5 A in 90 minutes. Effectivity in ferrous and manganese metal reduction was 98.7% and 99.6%, respectively. The final concentration of ferrous and manganese metal was 0.08 mg/L and 0.01 mg/L respectively. Optimum concentration of TSS reduction was 83.7% with the final concentration of 72 mg/L. The wastewater pH value became 7,1. Finally, the results demonstrated that the electrocoagulation process using aluminium electrode is a reliable technique for removal of pollutants from coal stockpile wastewater.