摘要:
分析深圳湾表层沉积物中锌、铬、镉、镍、铅、铜等6种重金属元素的含量发现它们的浓度均值已全部超过广东省海岸带沉积物背景值。根据潜在生态危害法,在6种重金属中镉造成的污染最严重,从潜在的生态危害指数评价看镉的含量已达到很高的污染水平。从面状分布看,重金属污染危害指数值在深圳河口区最低,在蛇口段居中等水平,在深圳湾内侧的近岸水域最大。柱样沉积物的浓度变化以1950年为界划分为两部分:1950年以来的现代沉积物中有较强的人类活动干扰痕迹,表现为重金属元素的浓度增长幅度大,且浓度很高,其均值全部大于广东省海岸带的背景值;1950年以前的近代沉积物中有稍弱的人类活动干扰痕迹。研究认为沉积物粒度特征、沉积速率、人类活动与重金属在沉积物中的浓度高低有直接相关关系,并直接影响到重金属在沉积物中的污染水平。
Abstract:
The contents of zinc,chromium,cadmium,nickel,lead and copper were measured on both suface sediments and core sediments in the Shenzhen Bay.The average contents of these metals showed that the contents of all the metals have exceeded the background values in the coastal zone of Guangdong Province.cadmium is a heavy pollution matter which indicates a strong pollution level according to the ecological risk coefficient method.The ecological risk index of the whole area is 299 which belongs to middle and strong level.The area with strong pollution level is the near shore area closing to the inside of Shenzhen Bay,Shakou coast is in the middle level while the weak pollution level occurs in the Shenzhen Estuary according to the ecological risk index.The four sediment cores can be divided into two parts based on lead-210 dating,sediment size analysis and economic development period in surrounding areas with a boundary of 1950.It has been a period with continuous increase of heavy metals since 1950 with strong human intervention.The sediment size,deposition rate and human activities have positive relationship with the contents of heavy metals which directly impact the pollution level of heavy metals in sediments of the Shenzhen Bay.
下载:
