Comprehensive evaluation of leaching toxicity of tailings in non-resource-based cities in Anhui Province based on entropy weight-clustering method

Toxic components in tailings pose a severe threat to the ecosystem and human health and negatively affect tailings’ resource utilization. Therefore, using the entropy weight-clustering method, we evaluated the leaching toxicity based on tailings samples from non-resource cities in Anhui Province. The results show that, all the extracted tailings samples first passed the leaching toxicity test, but there is still a large room for improvement. Secondly, there are complex interrelationships among the 15 indicators measuring leaching toxicity. Thirdly, in the process of entropy weight method calculation, the top three indicators in terms of weight are Cu (17.65%), Ag (16.52%), and Be (8.66%). Finally, the Ward clustering results show that the toxicity scores of tailings in each mining area exhibit distinct hierarchical characteristics, and they can be divided into two major categories and three subcategories (Ⅰ-1, Ⅰ-2, Ⅱ), with the toxicity scores of category Ⅰ-1 significantly higher than the rest of the mining areas. These findings provide empirical evidence for targeted treatment of tailings resources.