黄河内蒙古段表层沉积物对硝态氮的吸附动力学研究

Adsorption Kinetics of Nitrate Nitrogen in Surface Sediments of Yellow River from Inner Mongolia

该文于2013年春季、秋季和2014年秋季3个季度在黄河内蒙古段6个采样点进行采样,在实验室模拟条件下对黄河表层沉积物对硝态氮的吸附动力学进行了研究,结果表明：（1）黄河表层沉积物对硝态氮的吸附存在固体浓度效应现象,且不可逆。（2）沉积物对硝态氮的吸附量qe与吸附时间t在5~90 min时基本呈增长趋势,到90 min后吸附逐渐稳定。（3）吸附最小值出现在托县（2013年春季）,吸附量低至9.447 0 mg/kg,吸附量最大值出现在磴口（2013年秋季）,吸附量达33.670 8 mg/kg。春季时沉积物对硝态氮的吸附量明显高于秋季,但两年的秋季的吸附差异不明显。（4）黄河表层沉积物对硝态氮的吸附动力学符合Lagergren准二级动力学速率方程。

The adsorption kinetics of nitrate nitrogen in three quarters incluidng the spring of 2013, the autumn of 2013 and 2014 on the surface sediments from 6 different sampling points from Yellow River in Inner Mongolia were investigated under simulation environmental conditions. The results show that nitrate nitrogen adsorption deceased significantly with the increase of solid concentration （particle concentration effect） and the desorption of nitrate nitrogen on Yellow River sediments was irreversible.The adsorption rate of nitrate nitrogen on sediments were fast and the adsorption qe had a growing trend by the time in 5~90 min. the adsorption gradually stabled after 90 min. The minimum amount of adsorption capacity was 9.447 0 mg/kg, showed in the Tuokeuo County＇s spring sample of 2013.The maximum one was 33.670 8 mg/kg in the Dengkou＇s autumn sample of 2013. The adsorption capacity in spring was higher than in autumn, but there were no significant differences in autumn of 2013 and 2014. Adsorption kinetics of nitrate nitrogen in surface sediments followed the second- order adsorption kinetics model.