大沽排污河底泥释放总氮的影响

在实验室模拟条件下,考察了上覆水的溶解氧DO、pH值、温度、含盐量及扰动速率等环境因子对大沽排污河底泥释放总氮的影响.结果表明:厌氧条件下底泥释放总氮的强度高于好氧条件和自然条件下的释放强度;上覆水的pH呈中性时底泥释放总氮的强度最大,酸性条件下底泥释放总氮的强度高于碱性条件;升高温度可促进底泥释放总氮;扰动可提高底泥释放总氮的强度,但当扰动速率增加到一定程度时,反而会抑制总氮的释放,因此,至最后实验结束时,扰动速率为60r.min-1的体系中底泥释放总氮的能力最强;当实验达到平衡时,含盐量为0mg.L-1的体系中底泥释放总氮的能力最强.

Influencing factors of total nitrogen release from sediments in the Dagu drainage river

The effect of environmental factors including dissolved oxygen (DO) in overlying water and its pH, temperature and salinity, and velocity of disturbance on the release of total nitrogen from sediments of the Dagu drainage river were investigated under simulated test conditions. The results showed that when overlying water was in anaerobic conditions, the intensity of total nitrogen release was higher than that under aerobic and natural conditions. The intensity of total nitrogen release from sediments reached the highest level when pH of the overlying water was neutral, and the intensity of total nitrogen release from sediments was higher when the overlying water was acidic than alkaline. An increase in temperature could promote the release of total nitrogen from sediments. The disturbance of overlying water could increase the intensity of total nitrogen release from sediments. However, the intensity of total nitrogen release decreased when the velocity of disturbance was too high. The intensity of total nitrogen release was highest with the velocity of disturbance at 60 r·min^-1. When the salinity of overlying water was 0 mg·L^-1, the intensity of total nitrogen release also achieved the highest concentration until the simulation test approached to its balance.