沉积物对氨氮的吸附作用在河口湿地生态系统中的氮素循环过程中起着重要作用.采用实验室模拟的方法对珠江河口红树林、芦苇和光滩区表层湿地沉积物吸附氨氮的行为及影响因素进行研究.结果表明:3个不同区域沉积物对氨氮的吸附量呈现明显差异;植物区(红树林、芦苇区)沉积物对氨氮的承载能力强于光滩区;随上覆水盐度的增加,沉积物由吸附氨氮逐渐转变为释放氨氮;短时间水体扰动的加剧有助于沉积物吸附氨氮;沉积物对氨氮的吸附量随上覆水氨氮浓度升高而增加,但吸附率却逐渐下降;有机质含量的减少会降低沉积物对氨氮的吸附能力.
Adsorption of ammonia on sediments played an important role in the nitrogen cycle of estuarine wet- land eco-system. The ammonia nitrogen adsorption of sediments and its impact factors in mangrove, phragmites and tidal flats areas of Pearl River estuarine wetlands were investigated based on laboratory simulation experiments. The results indicated that the ammonia adsorption behavior of sediments in three regions presented obvious difference. The load-bearing capacity of ammonia in the plant area (mangrove and phragmites) sediments is stronger than that in tidal flats area. With the increase of salinity in overlying water, the sediment was gradually changed from ammonia storage media to the source of ammonia. And short time disturbance of water contributed to the ammonia adsorption on sedi- ment. The ammonia adsorption quantity of sediment was positive correlated with the ammonia concentration in overly- ing water, however, the ammonia adsorption rate presented the different tendency. In addition, the reduce of organic matter could lower the ammonia nitrogen adsorption capacity of sediments.