Justyna Kujawska, Wojciech Cel, Henryk Wasąg
Drilling waste constitutes industrial waste produced during mining activities involving drilling holes for exploration and exploitation. In Poland, the growing interest in shale gas, and the necessity of extracting it from significant depths led to the production of approximately 80 thousand tons of drilling waste (in 2013). Only a small part of this waste is utilized in the production of construction materials. Over 80% of produced waste is deposited either at the drilling site or on landfills. Therefore, it is important to assess the environmental risk connected with utilization of this type of waste. Drilling waste from shale gas mining contains various kinds of toxic heavy metals, which may be released into the environment by leaching. The paper describes the performed studies and presented the results of leachability, i.e. potential heavy metal mobility, from two types of drilling waste produced through the use of water- and oil-based drilling muds. Standard 24-hour extraction test was performed in water with solid to liquid phase ratio of 1 kg: 10 dm3. It was proven that the susceptibility of heavy metals to leaching from drill cuttings with water-based mud decreases in the order Ba > Zn > Pb > Cu > Ni > Cr, while in the case of drill cuttings with oil-based mud, it changes in the order Ba > Zn > Cr > Ni > Pb > Cu.
gaz łupkowy, odpady wiertnicze, metale ciężkie
Leachability of Heavy Metals from Shale Gas Drilling Waste
shale gas, drilling waste, heavy metals
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