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Nitrogen Runoff from Tunnel Blasted Rocks— a Large‐Scale Test
Author(s) -
Bækken Torleif
Publication year - 2014
Publication title -
water environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.356
H-Index - 73
eISSN - 1554-7531
pISSN - 1061-4303
DOI - 10.2175/106143014x13975035525023
Subject(s) - surface runoff , nitrogen , environmental chemistry , ammonium , slurry , environmental science , water quality , nitrate , ammonium nitrate , explosive material , environmental engineering , chemistry , ecology , organic chemistry , biology
Eight tunnel blasted rock samples were washed five times in 10 m 3 containers to calculate the runoff potential of nitrogen from unexploded remains of the ammonium nitrate slurry explosive in rock piles. During the first wash, 65% of total nitrogen was washed off. The average concentrations of NH 4 + and NO 3 − in the first wash water were 46 mg N/L and 58 mg N/L, respectively, being reduced to 2.5 and 1.2 mg N/L after the last wash. The average runoff of total nitrogen from the blasted rocks was 24.2 g N/ton, being 14.7% of nitrogen in the loaded explosives. pH was high (range 8.1 to 11.8) resulting from shotcrete spill, pushing the NH 4 + /NH 3 equilibrium toward the toxic NH 3 . The consequences of runoff from blasted rock piles may be damaging for water quality and biology in small recipients, and abatement measures should be assessed.