| 快速城镇化进程中珠江三角洲硝酸型地下水赋存特征及驱动因素 |
| 摘要点击 2102 全文点击 760 投稿时间：2021-02-19 修订日期：2021-03-15 |
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| 中文关键词 硝酸型地下水 赋存环境特征 驱动因素 珠江三角洲 城镇化 |
| 英文关键词 NO3-type groundwater geochemical characteristics driving factors Pearl River Delta urbanization |
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| 中文摘要 |
| 随着经济的发展，我国地下水硝酸盐污染日趋严重，城镇化和工业化是硝酸型地下水频繁显现的主要驱动力.本文以城镇化快速发展的珠江三角洲为研究区，运用数理统计、主成分分析及"双因子"等方法探讨了研究区浅层硝酸型地下水的赋存环境特征和驱动因素.结果表明，珠江三角洲地区地下水硝酸盐含量总体较高，全区1538组地下水样品中，硝酸盐浓度大于地下水Ⅲ类水质标准（88.6 mg·L-1）87组，超标率为5.7%；硝酸型水284组，占样品总数的18.5%.研究区硝酸型水分布广泛，主要分布于丘陵区及其与平原区交界处.其中广州、东莞、佛山和珠海等地区受城镇化和工业化影响出现了条带状的高溶解性总固体（TDS）硝酸型水，而在周边丘陵河谷区分布低TDS硝酸型水.西江、东江平原区，受工业废水及海咸水入侵影响，地下水TDS明显升高，该区域地下水NO3-质量浓度超Ⅲ类水标准但未影响水化学类型，然而工业化导致该区域硫酸型水频繁显现.研究区硝酸型水赋存于酸性或弱酸性环境，通常具有TDS和总硬度含量较低，Cl-、SO42-和K+浓度较高等特征.硝酸型水的形成主要受生活污水、工业废水、农业氮肥、化粪池和垃圾渗滤液泄漏等影响.通常，高TDS硝酸型水的污染负荷高于低TDS硝酸型水.硝酸型水尤其是低TDS硝酸型水的圈定有利于识别出人类活动影响更为强烈的地下水，能够尽早识别出硝酸盐含量低但已具有潜在污染风险的地下水，对地下水的污染防控具有重要意义. |
| 英文摘要 |
| In response to rapid economic development, nitrate pollution of groundwater is becoming a serious issue in many parts of China. Urbanization and industrialization are the main drivers of NO3-type groundwater expansion. Focusing on the Pearl River Delta, the occurrence and driving factors of shallow nitrate groundwater are discussed. Overall, groundwater nitrate concentrations are generally high in this region. Of 1538 groundwater samples, 5.7% had nitrate concentrations higher than the groundwater quality standard(88.6 mg·L-1) and 18.5% were classified as NO3-type waters, which are mainly distributed in the hilly and piedmont areas. Guangzhou, Dongguan, Foshan, Zhuhai and other areas show high total dissolved solid(TDS)-concentration NO3-type waters, which are affected by urbanization and industrialization. In comparison, low-TDS NO3-type waters are distributed in the hilly and valley areas. In the Xijiang and Dongjiang plains, the TDS concentrations on groundwater increased significantly due to inputs of industrial wastewater and saline seawater. The NO3- concentration in the groundwater in this area exceeded the class III water standard but did not change the hydrochemical type classification. However, industrialization has led to the frequent appearance of SO4-type water in this area. The NO3-type water occurs in acidic or weakly acidic environments, typically characterized by low TDS and total hardness concentrations, and high Cl-, SO42-, and K+ concentrations. The formation of NO3-type water is mainly affected by domestic sewage, industrial wastewater, agricultural nitrogen fertilizer, septic tank outflows, and landfill leachate leakage. Generally, the pollution loads of high-TDS NO3-type waters are higher than low-TDS NO3-type waters. The delineation of NO3-type waters, especially the low-TDS type, is helpful for identifying groundwaters posing greater risks for human activities, and those with low nitrate concentrations but potential pollution risk, which is of great significance in the prevention and control of groundwater pollution. |
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