研究报告
徐彩丽,罗春乐,薛跃君,葛田田,王旭晨.山东省降雨和降雪中溶解有机碳、溶解无机碳和总氮的浓度变化及来源分析[J].环境科学学报,2016,36(2):658-666
山东省降雨和降雪中溶解有机碳、溶解无机碳和总氮的浓度变化及来源分析
- Concentration and source assessment of dissolved organic and inorganic carbon and dissolved nitrogen in snow and rainfalls in Shandong Province
- 基金项目:国家自然科学基金(No.41476057,41221004)
- 徐彩丽
- 中国海洋大学化学化工学院, 教育部海洋化学理论与技术重点实验室, 青岛 266100
- 罗春乐
- 中国海洋大学化学化工学院, 教育部海洋化学理论与技术重点实验室, 青岛 266100
- 薛跃君
- 中国海洋大学化学化工学院, 教育部海洋化学理论与技术重点实验室, 青岛 266100
- 葛田田
- 中国海洋大学化学化工学院, 教育部海洋化学理论与技术重点实验室, 青岛 266100
- 王旭晨
- 1. 中国海洋大学化学化工学院, 教育部海洋化学理论与技术重点实验室, 青岛 266100;2. 青岛海洋科学与技术协同创新中心, 青岛 266100
- 摘要:测定了2014年山东省青岛、烟台和泰安三地32场降雨和4场降雪中溶解有机碳(DOC)、溶解无机碳(DIC)和溶解总氮(DN)的浓度.结果显示,降雨和降雪中DOC、DIC和DN的浓度具有很大的变化区间,范围分别为28~616 μmol·L-1、22~371 μmol·L-1和10~355 μmol·L-1,平均浓度与其他研究报道的我国其它地区降雨中的浓度相当,但高于世界其它地区降雨中的相应浓度. 溶解碳和溶解氮是山东降雨中重要的化学污染组分.分析发现,相对于陆地生成的降雨,海洋生成的降雨中含有较低的DOC、DIC和DN,说明雨水中溶解的碳和氮主要来自陆地人类向大气的排放.碳-14同位素分析结果证实,降雨中的DOC具有很老的年龄(平均达2840 a),主要来自化石燃料的排放,而雨水中的DIC主要来自大气中含碳酸盐的悬浮颗粒物的溶解;人类的排放也是造成雨水中高浓度DN的主要来源.计算结果表明,2014年山东降雨年输送通量分别为:DOC 1.51 g·m-2·a-1(以C计)、DIC 0.86 g·m-2·a-1(以C计)、DN 1.18 g·m-2·a-1(以N计),DOC通量与世界各地的降雨中DOC通量相当.降雨和降雪过程不仅是去除大气中可溶性碳氮污染物的重要途径,同时也是全球碳和氮循环过程中的重要一环.局部地区富营养化的降雨过程亦可能对陆地和海洋生态系统产生不可忽视的影响.
- Abstract:Concentrations of dissolved organic carbon(DOC), dissolved inorganic carbon (DIC) and dissolved total nitrogen (DN) were measured in 32 rainwater and 4 snow samples collected from Qingdao, Yantai and Taian in Shandong province in 2014. The results show that DOC, DIC and DN concentrations varied greatly, ranging from 28~616 μmol·L-1, 22~371 μmol·L-1 and 10~355 μmol·L-1, respectively. DOC and DN are the major dissolved chemical components in the precipitations. Rain and snow over the ocean usually had much lower concentrations of DOC, DIC and DN compared with those over the continent, suggesting that the dominant sources of these chemical components in precipitations were caused by the anthropogenic inputs. Carbon isotopic (14C and 13C) analysis of DOC and DIC revealed that the fossil fuel emission was the major contribution of the old carbon in rainwater DOC, and the excess DIC in the precipitations was likely due to the carbonate dusts that could dissolve in acidic rains. the estimated fluxes of DOC, DIC and DN in the rainfalls are 1.51 g(C)·m-2·a-1, 0.86 g(C)·m-2·a-1, and 1.18 g(N)·m-2·a-1, respectively. This suggests that precipitation is an important reason for the removal of anthropogenic carbon and nitrogen from the atmosphere and could contribute a significant fraction for the global carbon and nitrogen cycles, which impacts the continental and marine ecosystems.
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