选择长江口滨岸潮滩作为典型研究区,研究了排污活动对潮滩营养盐N环境地球化学过程的影响。结果发现排污口滨岸潮滩上覆水、表层沉积物孔隙水和表层沉积物中的NH4^+-N、TIN等都有显著累积效应,而NOx^--N在长江口滨岸潮滩上覆水、表层沉积物孔隙水和表层沉积物中并未出现累积高峰值,表明外源输入不是潮滩环境中NOx^--N主要来源。分析结果还显示,排污口潮滩沉积物-水界面间N分子扩散通量明显大于非排污口,表明排污活动加剧了潮滩沉积物-水界面间营养盐N的扩散过程
The influences of sewage discharge on environmental geo-chemical processes of nutrients were investigated in the Changjiang(Yangtze) River estuary in this study. The result indicates that there was obviously enrichment of NH4^+-N and TIN in tidal water, tidal surface-sediment pore waters and surface sediments adjacent to sewage outlets in the estuary. The enrichment of nitrogen was considered to be related not only to the inputs of nitrogen from sewage outlets, but also to the changes of environmental factors induced by sewage discharge. In contrast, there was no significant enrichment of NOx^--N in the tidal water, tidal surface-sediment pore waters and surface sediments from the estuary, which showed that external inputs of nutrients was not the primary factor controlling the distribution of NOx^--N. It was also shown that the diffusive fluxes of nitrogen across sediment-water interface was markedly higher at sewage outlets than at the control sampling sites in tidal flats, indicating that sewage discharge not only increased the accumulation of nitrogen in the tidal flat, but also strengthened the exchange process of nitrogen across tidal sediment-water interface.