Assessment on Sediment Pollution and Suggestions of its Disposal Method in a Reservoir Used as an Urban Water Source in China

In this study, sediment volume, heavy metals Cr, Ni, Cu, Zn, Pb, Hg, As, Cd and the nutrient substance such as TOC, TN, TP in sediment in a reservoir (an urban water source) in China were employed as the contamination index to assess the sediment pollution, using the method of index of geo-accumulation (I_geo). The result shows that, apart from sample 13# of Pb and 20# of Cu, the I_geos of which are between 0 and 1, there is no other heavy metal pollution occurred in the reservoir. For the nutrient matters, TOC, TP and TN, the pollution levels are below the national average in this reservoir. The sediment volume is estimated as 5.6 × 10₇ m₃, nearly 10% of the storage capacity of the reservoir at the normal water level, implying that the situation of the sediment will affect the water supply in some way and it is essential to take measures to control this potential sediment pollution. The authors suggest that the dredging technology is the most effective way to solve sediment pollution in this reservoir, as the nutrient matters in the sediment are much abundant and could be used for resource utilization, such as building materials, fill materials and land use. Compared to the others, land use shows more potential for future development.