| 南京近郊农田大气颗粒物及金属干沉降输入特征 |
| 摘要点击 1480 全文点击 1557 投稿时间：2022-06-20 修订日期：2022-07-20 |
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| 中文关键词 农田 大气颗粒物 重金属 粒径分布 干沉降 |
| 英文关键词 farmland atmospheric particulates heavy metals size distribution dry deposition |
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| 中文摘要 |
| 大气颗粒物中重金属干沉降输入是农业区域重金属的重要来源之一，但当前对农业区大气重金属沉降的观测研究较少.通过对南京近郊典型稻麦轮作区定点连续1 a采样，分析了不同粒径大气颗粒物和其中10种金属元素的浓度，并利用大叶模型估算其干沉降通量.结果表明，颗粒物浓度和干沉降通量均呈现冬春高、夏秋低的变化趋势；冬春季颗粒物污染为粗粒子（2.1~9.0 μm）和细粒子（<2.1 μm）的双重作用，而夏秋季则主要为细粒子的作用；金属元素浓度在巨粒子（>9.0 μm）中占比最低，在粗粒子和细粒子中相当，而Pb、Mn、As和Cd在细粒子中占比较高；10种金属元素的年均干沉降通量［mg ·（m2 ·a）-1］大小为：Ca （2096.4）>Al （1710.4）>Zn （855.0）>Fe （256.1）>Pb （40.35）>Cu （31.93）>V （26.21）>Mn （9.10）>As （2.48）>Cd （0.28）.研究结果为更加全面地认识人类活动对农产品质量安全和土壤生态环境的影响提供参考依据. |
| 英文摘要 |
| The dry deposition of heavy metals in atmospheric particulates is one of the important sources of heavy metals in agricultural areas, but there are few observational studies on the atmospheric deposition of heavy metals in agricultural areas. In this study, the concentrations of atmospheric particulates with different particle sizes and ten kinds of metal elements in them were analyzed by sampling a typical rice-wheat rotation area in the suburb of Nanjing for one year, and the dry deposition fluxes were estimated using the big leaf model, so as to understand the input characteristics of particulates and heavy metals. The results showed that the particulate concentrations and dry deposition fluxes were high in winter and spring but low in summer and autumn. In winter and spring, coarse particulates (2.1-9.0 μm) and fine particulates (<2.1 μm) had dual effects on particulate pollution, whereas in summer and autumn, particulate pollution was mainly attributed to the fine particulates. The concentrations of metal elements were the lowest in giant particulates (>9.0 μm) and were similar in coarse particulates and fine particulates, whereas Pb, Mn, As, and Cd elements were relatively high in fine particulates. The average annual dry deposition fluxes[g·(m2·a)-1] of particulates was giant particulates (8.31)>coarse particulates (5.99)>fine particulates (0.629). The order of average annual dry deposition fluxes[mg·(m2·a)-1] of the 10 metals was Ca(2096.4)>Al(1710.4)>Zn(855.0)>Fe(256.1)>Pb(40.35)>Cu(31.93)>V(26.21)>Mn(9.10)>As(2.48)>Cd(0.28). The average annual dry deposition fluxes of the 10 metal elements in fine particulates, coarse particulates, and giant particulates were 179.03, 2124.97, and 2724.18 mg·(m2·a)-1, respectively. These results will provide a reference for a more comprehensive understanding of the impact of human activities on the quality and safety of agricultural products and soil ecological environment. |
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