| 李霞,张慧鸣,徐震,金聪颖,白宏涛,汪磊,赵祯,孙红文.农田Cd和Hg污染的来源解析与风险评价研究[J].农业环境科学学报,2016,35(7):1314-1320. |
| 农田Cd和Hg污染的来源解析与风险评价研究 |
| Source apportionment and risk assessment of Cd and Hg pollution in farmland |
| 投稿时间：2015-12-24 |
| DOI：10.11654/jaes.2016.07.013 |
| 中文关键词: 重金属污染 风险评估 源解析 生物有效性 种植结构调整 |
| 英文关键词: heavy metal pollution risk assessment source apportionment bioavailability planting structure adjustment |
| 基金项目:农业部行业重大专项“农田土壤重金属污染修复示范试验（天津）”（2013145） |
| 作者 | 单位 | E-mail | | 李霞 | 环境污染过程与基准教育部重点实验室, 南开大学环境科学与工程学院, 天津 300071 | | | 张慧鸣 | 环境污染过程与基准教育部重点实验室, 南开大学环境科学与工程学院, 天津 300071 | | | 徐震 | 天津市农业环境保护管理监测站, 天津 300061 | | | 金聪颖 | 天津市农业环境保护管理监测站, 天津 300061 | | | 白宏涛 | 环境污染过程与基准教育部重点实验室, 南开大学环境科学与工程学院, 天津 300071 | | | 汪磊 | 环境污染过程与基准教育部重点实验室, 南开大学环境科学与工程学院, 天津 300071 | | | 赵祯 | 环境污染过程与基准教育部重点实验室, 南开大学环境科学与工程学院, 天津 300071 | | | 孙红文 | 环境污染过程与基准教育部重点实验室, 南开大学环境科学与工程学院, 天津 300071 | sunhongwen@nankai.edu.cn |
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| 中文摘要: |
| 以天津某郊区农田为研究对象，调查了土壤及农产品中Cd和Hg的污染状况，运用指数法评估其污染风险，利用GIS空间模型和同位素比值法分析了Cd和Hg的空间分布特征和污染来源，并筛选出生物富集低且经济效益可观的作物种类，为通过种植结构调整降低农田重金属污染风险提供依据。结果表明，研究区内部分农田受到了Cd和Hg的污染，安全土壤点位分别占19%和46%，污染土壤中有较多点位属于警戒（36%和17%）和轻污染（26%和19%），处于重度污染的小于10%，该区域种植的农产品中Cd和Hg超标率分别为17%和37%。基于GIS的空间分布显示：Cd主要以点源形式进入土壤，移动性较大；Hg以面源污染为主，以残渣态为主要形态。运用同位素比值分析法得出：研究区内土壤Cd污染主要来自工业废弃物及灌溉水，农产品中Cd污染主要来源于土壤；土壤Hg污染主要来自大气降尘、有机肥及灌溉水，农产品中Hg的污染来源主要有土壤和大气降尘。不同农作物对重金属的富集能力不同，瓜果类蔬菜对Cd和Hg的富集系数最低，果实中这两种重金属含量均在安全水平以内。研究表明，利用不同植物吸收重金属有效性的差异，通过种植结构的调整，可以在微污染农田中生产出安全农产品，为控制农田重金属污染风险提供了一条可行之路。 |
| 英文摘要: |
| Source apportionment and risk assessment are important two aspects for heavy metal pollution studies. In this study, levels of Cd and Hg in soil and agricultural products in a suburb of Tianjin were investigated. Their risk was evaluated by index methods and spatial distribution characteristics. Sources of Cd and Hg were studied by GIS-based space model and isotope ratio method. In addition, crops with low enrichment coefficients and high economic benefits were screened from various kinds of crops. Results showed that part of the investigated area suffered Cd and Hg pollution. Only 19% and 46% of the sites were Cd-and Hg-safe, respectively; whereas 36% and 17% were at warning and 26% and 19% at light pollution levels, respectively. Severely polluted sites were less than 10%. The percentages of polluted a gricultural products were 17% and 37% for Hg and Cd, respectively. In the studied area, Cd entered soil mainly via point sources and had high mobility; while Hg polluted soil primarily through non-point sources and existed largely as residue form. The heavy metal isotope ratio analysis revealed that soil Cd pollution was mainly from industrial waste and irrigation water and that Cd in agricultural products came most ly from soil. However, Hg pollution in soil resulted mainly from atmospheric deposit, organic fertilizer and irrigation water, and Hg in agricultural products was from soil and atmospheric dusts. The enrichment ability of heavy metals varied among crops, with the lowest enrichment found in melon and fruit vegetables, in which Cd and Hg content in fruits was safe. These results suggested that it is possible to pro duce safe agricultural products in slightly polluted farmland through adjusting planting structure, thus providing a practical way to control the hazard of heavy metal pollution in farmland. |
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