Lab-scale study on the application of In-Adit-Sulfate-Reducing System for AMD control

As an alternative method, In-Adit-Sulfate-Reducing System (IASRS), the method of placing the SAPS inside the adit, to have temperature constant at about 15 °C, was suggested. Lab-scale model experiments of IASRS were carried out. The models 1 and 2 were run at 15 °C and 25 °C, respectively. The model 1 contained about a half of COD in the beginning of the operation than that of model 2. Metal removal ratios were higher than 90% in both systems. Both systems showed the sulfate removal ratios of 23% and 27%, respectively, which were still considerably low, even though higher than those of presently operating systems. However, since the synthetic AMD used was very low in pH (2.8) and very high in sulfate concentration, if some suggested modifications were applied to the standard design, it is presumed that the sulfate removal ratio would have increased.