Environmental Quality Assessment Of Heavy Metals In Qingdao Offshore

Qingdao is one of the most important economic centers of coastal city in eastern ofChina. In recent years, sewage from land-based sources, unreasonable exploitation ofaquatic resources had resulted in such as eutrophication, heavy metal pollution andecological degradation in Qingdao coastal waters. This paper analyzes content anddistribution of heavy metals in surface sediments from Qingdao offshore and uses twokinds of heavy metal pollution evaluation methods to assess the environmental quality ofthe study area. Combining vertical distribution of heavy metal in core sediments with210Pbdating calculations, a series of results and viewpoints with regard to the heavy metalspollution history and accumulation characteristics in the Qingdao offshore were presented.The main conclusions are as follows:1: As we can see from the entire study area, grain size distribution characteristic ofsediment is closely related to the dynamic environment and provenance. Estuarine areas aremainly affected by the tidal current where fine particle of sediment increases. And thefarther from offshore, the relative increase in the clay tablets of components, while in thewave-dominated headland region grain size are relatively coarse.2: The heavy metals from surface sediments in study area were higher than those ofshallow waters, indicating that these harmful heavy metals in the investigation area are witha certain degree of enrichment, and its distribution is basically divided into three types:(1)Cr, Cu, Zn are as a class whose high value areas are broadly consistent with the shaledistribution area;(2) As, Cd, Pb are as a class and its high value areas concentrated in thesoutheast Laoshan waters;(3) the high value of Hg are concentrated in the northern part ofJiaozhou Bay.3: By Pearson correlation analysis of heavy metals in surface sediments from Qingdaooffshore, the results showed that the adsorption of fine particles affected the enrichment ofheavy metals Cr, Cu, Zn. The relationship between As, Cd, Pb and particle size is weak, butit may possibly be related with Qingdao ocean dumping. Through the river surface samplesfor comparative study, river sediments is one of the possible sources of heavy metals.4:5cores (QDZ02, QDZ10, QDZ14, QDZ24, QDZ25) of heavy metals with differentdepth features and deposition rate and210Pb dating analysis present heavy metalsdistribution are under the influence of centennial-scale human activities.5: As accumulate index shows, As elements accumulate in the southeast of Laoshanwaters and reach2grades (moderate contamination bias), and Cd elements accumulate inthe northeastern part of Jiaozhou Bay and reach1grades (light pollution), Cr, Cu elementaccumulate up to1grade (slightly polluted). Through Nemerow index consolidated results, the first class of Qingdao coastal sediments samples are up to89.80%, accounting for thevast majority, while the second and third class type of contaminated samples accounting for10.20%, concentrated in the southeast Laoshan seas and Jiaozhou Bay area.