Potential risk assessment of organic pollutants in coal mining water

In order to investigate the potential risk of organic pollutants in coal mining water, the persistence, bioaccumulation and toxicity of known organic pollutants in coal mining water were systematically simulated and assessed by using EPI Suite and toxicolgical data, and the analytic hierarchy process (AHP) was used to establish an evaluation system for priority organic pollutants in coal mining water based on two primary indexes and seven secondary indicators of toxic and environmental effects. The results showed that: ① there were 13 persistent persistent substances, 8 bioaccumulative substances and 1 toxic substances among 54 organic pollutants, halgenated hydrocarbons have the strongest persistence, polycyclic aromatic hydrocarbons have the strongest bioaccumulation, and the general trend of reaction rate with hydroxyl radicals (OH•) is as follows: ether>esters>halgenated hydrocarbons; aliphatic>aromatic. (Short-chain halgenated) aliphatic compounds have no bioaccumulative substances, and the bioaccumulation of polycyclic aromatic hydrocarbons is generally high, moreover, there were 4 or more benzene rings in the molecular structure of the bioaccumulative ones, and the increase in the number of benzene rings would lead to the enhancement of the bioaccumulation of polycyclic aromatic hydrocarbons. Triphenyl phosphate is a significant toxic substance, which needs to be focused on during coal mining water treatment. ② The 20 organic pollutants with the higher comprehensive score were screened out as priority pollutants in coal mining water, among which dichloromethane, 1,2-dichloroethane, toluene, dibutyl phthalate, di(2-ethylhexyl) phthalate, naphthalene, benzo a pyrene, dibenzo a, h anthracene, benzo b fluoranthracene, benzo k fluoranthracene and benzo a anthracene have the characteristics of emerging contaminants, however, the level of organic pollutants detected in coal mining water is insufficient to pose risks to human health and ecolgical environment presently, but with the implementation of national policies and the increase in demand for high-quality treatment and utilization of coal mining water. The control of organic pollutants in coal mining water will become an realistic demand for the protection and utilization of regional water resources, and the potential risk assessment system of priority organic pollutants constructed in this study can be used to screen out priority pollutants in coal mining water, and provide a theoretical basis for the future control of organic pollutants.