[Atmospheric nitrogen deposition in urban area of Beijing]

Using ion exchange resin columns method, atmospheric nitrogen deposition was observed in the urban area of Beijing from March to September in 2009. The average value of atmospheric nitrate nitrogen deposition was 40.59 mg x m(-2) and that of atmospheric sulfite nitrogen deposition was 14.66 mg x m(-2) from March to June. The average value of atmospheric nitrate nitrogen deposition was 75.13 mg x m(-2) and that of atmospheric sulfite nitrogen deposition was 20.67 mg x m(-2) from June to September. Observational results show that atmospheric nitrate and sulfite nitrogen deposition had obvious local difference, that is to say, there was relatively large amount of deposition around traffic arteries and power plants, which shows the character of line/point source of atmospheric nitrate and sulfite nitrogen deposition. The average value of atmospheric ammonia nitrogen deposition was 12.19 mg x m(-2) from March to June, and 8.46 mg x m(-2) from June to September. Observational results show that the change of atmospheric ammonia nitrogen deposition among observation points was obvious smaller than atmospheric nitrate and sulfite nitrogen deposition, which shows the character of non-point source of atmospheric ammonia nitrogen deposition.