Development Of Mist Maker Technology For Acid Mine Drainage Treatment In The Coal Industry

Abstrak

Acid mine drainage (AMD) is a critical environmental issue associated with low pH and elevated concentrations of dissolved metals, particularly iron (Fe), which can threaten aquatic ecosystems and surrounding communities. This study evaluated the effectiveness of a mist maker combined with lime for improving pH and reducing Fe concentration in AMD. An experimental pre-test and post-test design was applied using three treatment systems: mist maker aeration, lime neutralization, and a combined mist maker–lime treatment. Each experiment used 5 L of AMD, a 30-minute contact time, and three replications. The measured parameters were pH and Fe concentration, while data were analyzed descriptively and inferentially using a paired t-test. The combined mist maker–lime treatment showed the highest performance. It increased pH by 2.32 ± 0.21, from 3.59 ± 0.21 to 5.91 ± 0.03, and reduced Fe concentration by 2.03 ± 0.61 mg/L, corresponding to a removal efficiency of 94.4%. These improvements were statistically significant (p < 0.05). Lime treatment alone significantly increased pH by 1.81 ± 0.04 (p < 0.05), but its Fe reduction of 0.64 ± 0.57 mg/L was not statistically significant (p > 0.05). In contrast, mist maker treatment alone produced no significant change in pH or Fe concentration. These findings indicate that integrating mist maker aeration with lime neutralization enhances AMD treatment through synergistic aeration, pH adjustment, oxidation, and metal precipitation mechanisms. Therefore, this combined approach offers a rapid, effective, and practical alternative for Fe removal and AMD neutralization under short contact conditions in small scale practical treatment applications.