【摘要】 银川市面积最大的湿地——阅海,春季水质差,农业面源污染的贡献大。为深入认识春灌期阅海水体中氮磷的分布规律和富营养化情况,于2021年春灌期采集了阅海及其出湖河流共28个代表性点位的水体样品,分析了阅海水体总氮(total nitrogen,TN)、总磷(total phosphorus,TP)和不同形态氮磷的分布特征和规律,揭示了阅海及其出湖河流的氮磷浓度差异性。结果表明,春灌期阅海水体78%采样点的TN浓度劣于地表水III类标准,57%采样点的TN浓度属于重富营养型。春灌期阅海水体各采样点TP浓度均劣于地表水III类标准,70%采样点的TP浓度属于重富营养型。阅海中不同形态氮在水体中的来源和转化过程存在差异,酸碱度(p H)及溶解性总固体(total dissolved solids,TDS)影响水体氮磷浓度,溶解氧(dissolved oxygen,DO)对水体氮磷形态的影响不明显。阅海出湖河流与阅海水体的氮磷分布特征不同,在河湖水体流向(南北方向)上,河湖水体间氮浓度及非正磷酸盐磷浓度差异不显著。阅海水体中的氮磷污染物随出湖河流汇入黄河,阅海水体中的氮及非正磷酸盐磷可能会对黄河宁夏段水体产生一定影响,增加黄河水污染风险,应加强对阅海水体氮及非正磷酸盐磷的控制。研究结果为持续精准提升黄河流域中上游水质提供参考。更多还原

【Abstract】 Yuehai is the largest wetland in Yinchuan of poor water quality during spring, with a significant contribution from agricultural non-point source pollution. In order to gain a deeper understanding of the distribution characteristics of nitrogen and phosphorus in the Yuehai Lake and its eutrophication status, water samples from 28 representative sites in Yuehai Lake and its outflow river were collected during the spring irrigation period of 2021. The distribution characteristics and regularities of TN(total nitrogen)and TP(total phosphorus), as well as different forms of nitrogen and phosphorus in Yuehai Lake were analyzed. The differences in nitrogen and phosphorus concentration between Yuehai Lake and its outflowing river were revealed. The results showed that during the spring irrigation period, the TN concentrations at 78% of the sampling points in Yuehai Lake was lower than the Class III surface water standard, and the TN concentration at 57% of the sampling points belonged to the heavily eutrophic type. During the spring irrigation period, the TP concentration at all sampling points was lower than Class III surface water standard, and the TP concentration at 70% of the sampling points belonged to the heavily eutrophic type. There were differences in the sources and transformation processes of different nitrogen fractions in the water of the Yuehai Lake. p H and TDS(total dissolved solids) affect the concentration of nitrogen and phosphorus in the water, and DO(dissolved oxygen) does not have a significant effect on the nitrogen and phosphorus forms in the water of the Yuehai Lake. The distribution characteristics of nitrogen and phosphorus in the outflow river of the Yuehai and the Yuehai water were different, and the differences in nitrogen concentration and non-orthophosphate phosphorus concentration between the Yuehai Lake and its outflow river were not significant in the direction of river and lake water flow(north-south direction). The nitrogen and phosphorus pollutants in the Yuehai converged into the Yellow River along with the rivers out of the Yuehai Lake, and the nitrogen and non-orthophosphate phosphorus in the Yuehai Lake might impact on the water of the Ningxia section of the Yellow River and increase the risk of pollution of the Yellow River, and the control of the nitrogen and non-orthophosphate phosphorus in the Yuehai Lake should be strengthened. This work provides a reference for continuously and accurately improving the water quality in the middle and upper reaches of the Yellow River Basin.更多还原