State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
Chemosphere. 2011 Jan;82(2):223-8. doi: 10.1016/j.chemosphere.2010.10.017. Epub 2010 Oct 30.
The concentrations of black carbon (BC), total organic carbon (TOC) and polycyclic aromatic hydrocarbons (PAHs) have been determined in soils from urban and rural areas of Beijing. The rural area can be divided into plain and mountainous areas which are close to and relatively far from the urban area, respectively. Concentration of BC (5.83 ± 3.05 mg g⁻¹) and BC/TOC concentration ratio (0.37 ± 0.15) in Beijing's urban soil are high compared with that in world background soils and rural soils of Beijing, suggesting the urban environment to be an essential source and sink of BC. Concentration of BC in the urban area decreases from the inner city to exterior areas, which correlates with the urbanization history of Beijing and infers accumulation of BC in old urban soils. Black carbon in Beijing soils mainly comes from fossil fuel combustion, especially traffic emission. Median PAH concentration in the urban area (502 ng g⁻¹) is one order of magnitude higher than that in the rural plain (148 ng g⁻¹) and mountainous area (146 ng g⁻¹) where PAHs are supposed to mainly come from atmospheric deposition from the urban area. Concentrations of BC correlate significantly with those of PAHs (p < 0.01, except naphthalene) in the urban area and with those of heavier 4-, 5- and 6- ring PAHs (p < 0.01) in the adjacent rural plain area, while there is no significant correlation with any PAH in the farther rural mountainous area.
已测定北京城乡土壤中的黑碳 (BC)、总有机碳 (TOC) 和多环芳烃 (PAHs) 的浓度。农村地区可分为与市区接近的平原地区和相对较远的山区。与世界背景土壤和北京农村土壤相比，北京城区土壤中 BC 的浓度（5.83 ± 3.05 mg g⁻¹）和 BC/TOC 浓度比（0.37 ± 0.15）较高，表明城区环境是 BC 的重要源汇。城区 BC 的浓度从市中心向外部区域逐渐降低，这与北京的城市化历史有关，并推断出旧城区土壤中 BC 的积累。北京土壤中的黑碳主要来自化石燃料燃烧，特别是交通排放。城区中 PAHs 的中值浓度（502 ng g⁻¹）比平原地区（148 ng g⁻¹）和山区（146 ng g⁻¹）高一个数量级，而平原和山区的 PAHs 应该主要来自城区大气沉降。城区中 BC 与 PAHs（萘除外，p < 0.01）浓度显著相关，与相邻平原地区较重的 4、5 和 6 环 PAHs（p < 0.01）浓度显著相关，而与较远山区的任何 PAH 浓度均无显著相关性。
