Oh Chamteut, Ji Sangwoo, Yim Giljae, Cheong Youngwook
Geologic Environment Division, Korea Institute of Geoscience and Mineral Resources, Daejeon, South Korea.
Climate Change Mitigation and Sustainability Division, Korea Institute of Geoscience and Mineral Resources, Daejeon, South Korea.
Environ Monit Assess. 2017 Apr;189(4):165. doi: 10.1007/s10661-017-5869-7. Epub 2017 Mar 15.
The main purpose of this research was to evaluate the geochemical properties of rocks for a single indicator of acid-forming potential. The indicators, such as net acid generation (NAG), NAG pH and total S, were applied to 312 rock samples of various geological characteristics. Additional indicators, such as a Modified NAG pH, paste pH and available acid neutralizing capacity (ANC), were applied to 22 selected samples. Among them, NAG pH was considered the most plausible single indicator in evaluating acid-forming potential, as it is simple to measure, widely applicable to various samples and can be used to estimate the NAG value. The acid-forming potential of 287 samples (92% of samples examined in this research) was classified as either non-acid forming (NAF) or potentially acid forming (PAF) by NAG pH, with an NAF criteria of <3.21 and PAF of >4.52. The NAG pH was also a good estimate of the risk of short-term acid release when combined with paste pH information. However, application of NAG pH to coal mine wastes, with high organic carbon contents, produced erroneous results due to the generation of organic acid during the NAG test. In this research, a Modified NAG pH was assessed as an alternative to NAG pH in such situations.
本研究的主要目的是评估岩石的地球化学性质，以确定一个单一的产酸潜力指标。将净产酸量（NAG）、NAG pH值和总硫等指标应用于312个具有不同地质特征的岩石样本。还将改良NAG pH值、浆体pH值和有效酸中和能力（ANC）等其他指标应用于22个选定样本。其中，NAG pH值被认为是评估产酸潜力最合理的单一指标，因为它测量简单，广泛适用于各种样本，并且可用于估算NAG值。根据NAG pH值，287个样本（占本研究检测样本的92%）的产酸潜力被分类为非产酸（NAF）或潜在产酸（PAF），NAF标准为<3.21，PAF标准为>4.52。当与浆体pH值信息结合时，NAG pH值也是对短期酸释放风险的良好估计。然而，由于在NAG测试过程中会产生有机酸，将NAG pH值应用于高有机碳含量的煤矿废弃物时会产生错误结果。在本研究中，评估了改良NAG pH值作为在这种情况下替代NAG pH值的指标。
