title: Nitrogen runoff from tunnel blasted rocks--a large-scale test.
abstract: Eight tunnel blasted rock samples were washed five times in 10 m3 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 NH4+ and NO3- 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 NH4+/NH3 equilibrium toward the toxic NH3. 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.
authors.forename: Torleif
authors.initials: T
authors.lastname: Baekken
mesh_terms: D064751:Ammonium Compounds / Q000737:chemistry; D004784:Environmental Monitoring; D053834:Explosive Agents / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste / Q000032:analysis*; D009566:Nitrates / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry*; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D064751:Ammonium Compounds; D053834:Explosive Agents; D007220:Industrial Waste; D009566:Nitrates; D014874:Water Pollutants, Chemical; D014867:Water; D009584:Nitrogen