疏浚对影响上覆水体自净能力的研究

Influence of Dredging on Self-Purification Ability of Overlying Water

分别在已疏浚和未疏浚河道底泥的影响下,考察了上覆水体自净系数———BOD减少速度系数和COD减少速度系数,以比较疏浚对于改善水体自净能力的效果。实验发现,疏浚前后,底泥向上覆水体释放污染物的规律虽然有所不同,但是释放通量均较大,严重影响上覆水体水质。若疏浚深度不足以疏浚掉大部分受污底泥,则疏浚对于抑制底泥影响上覆水体水质的效果不理想。

We examined self- purifying coefficient- BOD and COD reduction coefficient in overlying water at the presence and absence of dredging sediment as well as comparison the dredging effectiveness. It has been found that no matter having dredging or not, the releasing flux from sediment were both large enough to deteriorate the overlying water quality, although releasing regularity of sediment was somewhat different. If the most polluted sediment was not dredged, the overlying water quality could not be improved because of the releasing pollutants from sediment.