Assessment of Geogenic Contaminants in Water Co-Produced with Coal Seam Gas Extraction in Queensland, Australia: Implications for Human Health Risk

Geosciences

William Stearman¹  Mauricio Taulis¹  James Smith¹ 

[1] School of Earth, Environmental and Biological Sciences, Queensland University of Technology, R Block, 2 George St, Brisbane, QLD 4001, Australia; E-Mails:

关键词: coalbed methane;    coal seam gas;    coalbed natural gas;    co-produced water;    polycyclic aromatic hydrocarbons;   

DOI  :  10.3390/geosciences4030219

来源: mdpi

【 摘 要 】

Organic compounds in Australian coal seam gas produced water (CSG water) are poorly understood despite their environmental contamination potential. In this study, the presence of some organic substances is identified from government-held CSG water-quality data from the Bowen and Surat Basins, Queensland. These records revealed the presence of polycyclic aromatic hydrocarbons (PAHs) in 27% of samples of CSG water from the Walloon Coal Measures at concentrations <1 µg/L, and it is likely these compounds leached from in situ coals. PAHs identified from wells include naphthalene, phenanthrene, chrysene and dibenz[a,h]anthracene. In addition, the likelihood of coal-derived organic compounds leaching to groundwater is assessed by undertaking toxicity leaching experiments using coal rank and water chemistry as variables. These tests suggest higher molecular weight PAHs (including benzo[a]pyrene) leach from higher rank coals, whereas lower molecular weight PAHs leach at greater concentrations from lower rank coal. Some of the identified organic compounds have carcinogenic or health risk potential, but they are unlikely to be acutely toxic at the observed concentrations which are almost negligible (largely due to the hydrophobicity of such compounds). Hence, this study will be useful to practitioners assessing CSG water related environmental and health risk.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.