Heavy metal pollution and ecological risk assessment of water-based drill cuttings produced in shale gas exploitation in Chongqing, China

Shale gas exploitation is booming in China. Unlike the traditional oil extraction industry, shale gas extraction will generate more solid waste. Water-based drill cuttings (WBDC) as one of them is currently under regulatory vacuum. This article studied the status of heavy metal pollution and evaluated the ecological risk of WBDC. Cd, Cr, Cu, Hg, Mn, Ni, Pb and Zn were selected for the study. The results showed that except for Ni, other heavy metals showed different degrees of pollution, but the leaching toxicity was rather limited. Meanwhile, the ecological risks of all samples were significant, which posed a huge threat to environment. Though its limitation, this article can provide theoretical foundation for regulatory decisions of WBDC.