Distribution, sources and transport of polycyclic aromatic hydrocarbons (PAHs) in karst spring systems from Western Hubei, Central China. (August 2022)

• Record Type: Journal Article
• Authors: Chen, Wei; Zhang, Ziqiong; Zhu, Ying; Wang, Xianzhen; Wang, Longliang; Xiong, Junwu; Qian, Zhe; Xiong, Shuai; Zhao, Ruichao; Liu, Wei; Su, Qiuke; Zhou, Jiangang; Zhou, Hong; Qi, Shihua; Jones, Kevin C.
• Is Part Of: Chemosphere. Volume 300(2022)
• Publication Date: 2022-08
• Subjects: Karst spring -- Polycyclic aromatic hydrocarbons (PAHs) -- Transport -- Source analysis -- Hydrogeological conditions -- Western Hubei; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2022.134502
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Karst groundwater is an important water resource but it is vulnerable to contaminants, due to the distinctive geological features of abundant transmissive fractures and conduits in the karst area which connect the surface to the underground systems. Anthropogenic activity-derived polycyclic aromatic hydrocarbons (PAHs) on the surface environment could enter groundwater easily and rapidly and threaten water security in karst areas. Samples in the multimedia environment from 10 specific karst spring systems from Western Hubei of Central China were collected to analyze 16 priority PAHs and to investigate their transport in these karst spring systems. The total concentrations of PAHs in the soil, river water, river sediments, spring water, and spring sediments ranged between 6.04 and 67.7 ng g −1, 4.56 and 11.4 ng L −1, 29.9 and 1041 ng g −1, 4.09 and 222 ng L −1, and 5.88 and 83.0 ng g −1, respectively. Levels of PAHs in this area were relatively low when compared to other karst areas. Proportions of low-molecular-weight (LMW)-PAHs in the water, sediments and soil (average 58.2–78.8%) were much higher than those of high-molecular-weight (HMW)-PAHs. The proportion of LMW-PAHs in the sediments (especially in river sediments) was higher than that in the soil. Characteristic ratio analysis and principal component analysis showed that PAHs were from high-temperature combustion of the mixture of coal and biomass, and vehicle emission, where coal and biomass combustion were the dominant sources. Significant correlations of PAH compositions in different media of karst spring systems were observed, especially in the Yuquangdong (YQD)-Migongquan (MGQ), Jiuzhenziquan (JZZQ), Xianyudong (XYD) and Fengdong (FD) karst spring systems, indicating the rapid PAH transport from the recharge area soil to the discharge area of spring water and sediments. Graphical abstract: Image 1 Highlights: Particle-promoted transport with rapid water flow was pivotal for PAH mobilization to sediments. Different sources and matrix components lead to the differences in PAH concentrations and compositions in river sediments and spring sediments. Coal combustion, biomass burning and vehicle emission account for 99.1% of sources of the total PAHs. Significant correlations of PAH compositions were observed in the multimedia environment of karst spring systems.