Sedimentary Records of Heavy Metals in the Coastal Mud Area of the East China Sea
|School||Ocean University of China|
|Keywords||East China Sea Inshore mud area Heavy metal Sedimentary record Human activities|
The heavy metal pollution is one of the hotspots of land-ocean interaction in scientific research and the marine environment. The East China Sea mud area is the center of the accumulation of modern continental shelf of the East China Sea, is a good place to study modern human activities pollutants on the environment of the East China Sea. Research through the the inshore muddy area of ??the East China Sea S6 hole regular column-like distribution of metal elements, and a comparative study with the suspension of the Yangtze River, the Yellow River downstream metal elements, designed to reveal the impact of the past century of human activities on the coastal environment in the East China Sea. and extract better able to identify the human heavy metal pollutants geochemical indicators. Yangtze River, the Yellow River is the major source of sediment transport in the eastern China Sea, occupy a prominent position in the LOICZ research. The suspension element geochemistry of the Yangtze River, the Yellow River downstream Show: the lower reaches of the Yangtze River suspension elements Fe, Pb, Cu, Zn, V, Ni content follow granularity control law, that content as particle size decreases. Pb, Zn content significantly in the summer than in the winter high Yangtze serious contamination. The suspension element content of the lower reaches of the Yellow River is characterized by high Ca, Na, other elements than the Yangtze low. Ca / Mg, Mn / Cu, K / Na, K / Ca, Al / Na ratio of the Yangtze River and the Yellow River a huge difference, can be used as the indicator of the Yangtze River, Yellow River substances discriminant. Column S6 hole-like mud area is located along the coast south of 182cm above the sediment is mainly composed of silt and clay, poorly sorted, small changes in the composition of granularity, to reflect the stability of sediment sources and depositional environment. The Mn / Fe, Mn / Cu, Cr / Ti, Cu / Ni ratio showed that the deposition environment in the 182cm more stably and continuously, the sediment from the Yangtze substance. At the same time according to 210 sup> Pb dating results to get S6 hole column The average deposition rate of 0.98cm / a, resulting column-like layers approximate age, in 100cm at sediment age of about 101 years, equivalent to the early 20th century. Prior to this, very few Chinese industrial pollutants enter the East China Sea by the Yangtze River rarely. Average of 100 ~ 182cm paragraph layers element content as the value of the heavy metals in the background. Background values ??obtained by calculating the respective elements are as follows: a the of Cr 95.14μg / g Ni of as 46.87μg / g Pb for 31.76μg / g, As, for 13.21μg / g Cu of as 33.73μg / g Containing Trace, Zn for 115.11μg. / g. Since the reform and opening up, along with the rapid development of industry and agriculture and economic damage to the environment of human activities on the Yangtze River basin has led to serious soil erosion, but also caused serious environmental pollution. 23 ~ 3cm segment sediments (the equivalent of the 20th century, the 80s first arrived in the late 1990s) often trace elements and pollution element content quickly increased to reflect exactly this situation. Which 0 ~ 3cmPb had sharp decline reflected into the East China Sea since 2000, China has begun to restrict the use of leaded gasoline, Pb pollution reduction. The elements Pb on human activities affect the reaction is the most sensitive and effective, and can be used as geochemical indicators to identify the human heavy metals pollutants.