疏浚水体底泥再淤积过程研究

为保障疏浚效果的长效性,对疏浚前后底泥的淤积过程进行了模拟研究,并结合淤积过程中底泥性质和上覆水水质的变化,分析了疏浚水体底泥淤积的规律。结果表明,疏浚后底泥的淤积速率大幅提高,可由疏浚前的0.13 mm/d增至0.25 mm/d;疏浚后淤积底泥具有颗粒粒径大、含水率和有机质含量较高的特点;疏浚前后上覆水SS含量的变化不大,发生沉降的固体总量基本不变。由于疏浚前和疏浚后淤积底泥固体总量基本不变,而后者的粒径和含水率要高于前者,故相应的底泥体积和淤积厚度也要高。同时,疏浚后上覆水CODCr含量要高于疏浚前,这可能会导致水体上覆水水质恶化,并加速底泥的淤积。

Redeposition process of bottom sediments of water body after dredging

The deposition process of bottom sediments of water body before and after dredging was stimulated in order to guarantee the long effectiveness of dredging project, and the regularity of bottom sediments of dredging was studied according to the properties of bottom sediments and the water quality of overlying water. The results showed that the deposition significantly from 0. 13 mm/d to 0. 25 mm/d after dredging velocity of bottom sediments was increased. The particles of new bottom sediments after dredging had the features of larger diameter, higher water content and organic matter content. Suspended substance content of overlying water after dredging was close to that before dredging, amount was almost invariant. Under conditions of almost same total solid deposited, th and the total solid e bottom sediments after dredging had larger volume and higher thickness compared to that of bottom sediments before dredging because of its larger diameter and higher water content. Meanwhile, CODcr content of the overlying water was increased after dredging accelerate the deposition of bottom sediments. , and it would induce deterioration of water quality and