黄河泥沙对氮迁移转化的影响及环境效应

Effects and environmental implications of suspended sediment on the transportation and transformation of nitrogen in the Yellow River

黄河具有高泥沙含量的特点,泥沙对营养元素和污染物的迁移转化具有重要的影响。含氮化合物是我国河流的主要污染物之一,是国家重点防控污染物,是影响河流水体健康的重要因素。本文基于实验室模拟实验和野外采样研究成果系统综述了泥沙对河流氮迁移转化的影响及其环境效应。重点分析了(1)黄河水体含氮化合物的时空分布特征及来源;(2)含氮化合物的悬浮泥沙-水界面过程以及悬浮泥沙对氮转化过程的促进作用;(3)悬浮泥沙含量和粒径等对有机氮降解、硝化作用、反硝化作用、耦合硝化反硝化作用以及厌氧氨氧化作用的影响;(4)泥沙对温室气体N2O产生和排放的影响,以及(5)水沙条件变异对氮迁移转化作用的影响。研究结果可为气候变化和人类活动双重作用下河流氮污染治理以及温室气体的排放控制提供科学依据。

The Yellow River is featured by high suspended sediment(SPS)concentration,and sediment plays an important role in transportation and transformation of nutrients and contaminants in river systems.Nitrogenous compound is one of the primary contaminants in river systems and has a high priority in water pollution control in China for its severe influence on water quality and health.to investigate The effect and environmental implication of SPS on the transportation and transformation of nitrogen are investigated on the basis of incubation experiments and field observations,of which five aspects are highlighted:(1)the spatio⁃temporal distribution patterns and sources of nitrogenous compounds in the Yellow River;(2)processing of nitrogenous compounds at the SPS-water interfaces and stimulation of SPS on nitrogen transformations;(3)the effect of concentration and particle size distribution of SPS on mineralization,nitrification,denitrifica⁃tion,coupled nitrification-denitrification,and anammox;(4)the effect of SPS on N2O production and emis⁃sion;(5)the nitrogen transport and transformation under the conditions of variable incoming water and sedi⁃ment.The review is expected to lay a scientific basis for the regulation of nitrogen pollution and control of greenhouse gas emissions in rivers under the combined impacts of climate change and human disturbance.