Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100190, China.
Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100190, China.
Environ Pollut. 2018 May;236:177-187. doi: 10.1016/j.envpol.2018.01.078.
By identifying the main sources of nitrate (NO) can obtain useful information to support the management of NO pollution, particularly in subtropical catchments with shallow drinking water wells. This study used water chemistry and dual stable isotopes δN and δO methods to assess seasonal and spatial variations of NO in precipitation, surface water, and groundwater in an agricultural and forest subtropical catchment in Jiangxi Province, China. The maximum concentrations of nitrate-nitrogen (NO-N) and ammonium-nitrogen (NH-N) were 10.4 and 10.8 mg Lin samples collected from 221 rainfall events from 2011 to 2013. About 4.4% and 12.3% NH-N concentrations of surface water and groundwater exceeded the thresholds of 1.0 and 0.2 mg L. The NO-N concentrations in surface water were closely correlated with NH-N concentrations in surface water and groundwater (r = -0.71 and r = -0.71, P < 0.05). The concentrations of NH-N and NO-N were significantly higher in a fishery pond and nearby drinking wells than in other monitoring points. Annual exports of NO-N and NH-N were 4.06 × 10 and 8.14 × 10 kg yr, respectively and NO-N is the main form of N loss. The δN values ranged from 0‰ to 20‰ in surface water and groundwater, and the δO values ranged from 0‰ to 15‰ and 1‰-13‰, respectively. Dual stable isotope natural abundance distribution and water chemistry [NO]/[Cl] molar ratio information suggested that manure and sewage and soil N were the main sources of NO in surface water and manure and sewage in groundwater in summer and winter. In spring, water occurred denitrification and ammonium fertilizer, manure and sewage were the main sources of NO in surface water and groundwater which sampling points were closer residential area and fish ponds than paddy field and local farmers used more Manure. Manure applications should be reasonable around drinking water wells to protect the drinking water quality.
通过识别硝酸盐（NO）的主要来源，可以获得有用的信息来支持对 NO 污染的管理，特别是在浅层饮用水井的亚热带集水区。本研究采用水化学和双重稳定同位素δN 和 δO 方法，评估了中国江西省一个农业和森林亚热带集水区降水、地表水和地下水在季节和空间上的 NO 变化。从 2011 年至 2013 年采集的 221 次降雨事件中，硝酸盐氮（NO-N）和铵氮（NH-N）的最大浓度分别为 10.4 和 10.8mg/L。地表水和地下水中约有 4.4%和 12.3%的 NH-N 浓度超过 1.0 和 0.2mg/L 的阈值。地表水的 NO-N 浓度与地表水和地下水的 NH-N 浓度密切相关（r=−0.71 和 r=−0.71，P<0.05）。渔业池塘及其附近的饮用水井中的 NH-N 和 NO-N 浓度明显高于其他监测点。NO-N 和 NH-N 的年排放量分别为 4.06×10 和 8.14×10kg/yr，NO-N 是 N 损失的主要形式。地表水和地下水中的 δN 值范围为 0‰至 20‰，δO 值范围分别为 0‰至 15‰和 1‰至 13‰。双重稳定同位素自然丰度分布和水化学[NO]/[Cl]摩尔比信息表明，夏季和冬季地表水的主要 NO 来源是粪肥和污水以及土壤 N，地下水的主要 NO 来源是粪肥和污水。在春季，地表水和地下水发生反硝化作用和铵肥，粪肥和污水是靠近居民区和鱼塘的采样点地表水和地下水的主要 NO 来源，而稻田和当地农民使用的有机肥较少。在饮用水井周围应合理施用有机肥，以保护饮用水水质。
