Pollution characteristics and assessment of sulfide tailings from the Dabaoshan Mine, China

Sulfide at mine tailing ponds poses a source of contamination to the surrounding environment. This study was designed to investigate and assess the fresh and weathered tailings pollution in the vicinity of the Dabaoshan Mine in Guangdong Province, China for in situ rehabilitation. Characterization of the fresh and weathered tailings was performed using geochemical and mineralogical analysis. Results indicated that low sulfur weathered and fresh tailing samples still presented a relatively high acid-production potential. Cu, Zn, Pb, and Cd in fresh tailing samples mainly existed in sulfides, whereas residual silicates were the dominant chemical forms of the four metals in weathered tailing samples. According to Hakanson's ecological risk index assessment, the potential risk individual coefficients of four heavy metals similarly ranked as follows: Cd > Cu > Zn > Pb. The tailing samples in the Dabaoshan Mine presented a much high potential ecological risk. The health risk assessment showed that the carcinogenic risk and non-carcinogenic risk levels of heavy metals in tailing were both lower than 10−6 and 1.0, respectively. The main exposure route of total non-carcinogenic risk from the tailing was the ingestion of tailing particles.