南沙群岛西部海域两柱状沉积物中碳和氮的分布和来源特征及埋藏通量估算

对位于南沙群岛海域西部近大陆架-残留沉积区(NS01站)和深海沉积区(NS02站)的2个沉积物柱状样进行了研究,测定了它们的粒度组成、CaCO3含量、总有机碳含量(TOC)、总碳含量(TC)、总有机物含量(TOM)和总氮含量(TN),估算了它们的埋藏通量及陆/海源TOC和TN的相对含量.结果表明,该海域沉积物主要是粒径小于63μm的细粒度组分,粒度组成随深度的变化很小.沉积物粒度不是控制CaCO3含量、TOC、TC、TOM、TN和TOC/TN垂向变化的主要因素.NS01站CaCO3含量、TOC、TC、TOM和TN的含量及埋藏通量均低于NS02站.NS01站TOC/TN随深度的变化主要受控于TN的变化,而NS02站则主要受控于TOC的变化.2个研究站位的TOC和TN均以海洋自生为主,NS01站沉积物中海洋自生TOC和TN的平均值分别为53.2%和81.4%,NS02站沉积物中海洋自生TOC和TN的平均值分别为64.5%和87.7%

Elementary Study on the Geochemical Behaviour of Cu,Pb,Cd in the Jiulong Estuary,Xiamen

于2006年4月采集厦门九龙江河口水样,测定其溶解、颗粒态Cu、Pb、Cd及相关水化学参数的含量.结果表明,厦门九龙江河口区表层海水中溶解态Cu、Pb、Cd的含量范围分别为0.96～2.16、1.02～2.49及0.16～0.44μg/L,平均值分别为1.52、1.60和0.34μg/L;颗粒态Cu、Pb、Cd的含量范围分别为0.26～3.40、0.11～6.00、0.000 4～0.028 0μg/L,平均值分别为1.08、1.61和0.0064μg/L.在垂直变化上,除Cd变化较小外,Cu和Pb浓度随深度增加而逐渐升高,其贡献主要来自底部沉积物再悬浮.九龙江河口溶解和颗粒态Cu、Pb、Cd的平均入海通量分别为6.57、6.91、1.47、4.66、6.96和0.027 kg/d.九龙江河口区表层水体中Cu、Pb、Cd的表观分配系数(Kd)分别为4.09、2.84和0.10 L/kg.3种金属在研究海域的固-液分配机制主要受"颗粒物浓度效应"影响,而Cd在低盐度区受到"盐度效应"的影响.Seawater samples collected from 7 stations of the Jiulong Estuary in April 2006 and analyzed for dissolved and particulate heavy metals including Cu,Pb and Cd.The range of concentrations of dissolved Cu,Pb,Cd were 0.96~2.16,1.02~2.49,0.16~0.44 μg/L,with average values of 1.52,1.60,0.34 μg/L,separately;while that of particulate phases were 0.26~3.40,0.11~6.00,0.000 4~0.028 0 μg/L,with mean values of 1.08,1.61,0.006 4 μg/L,separately.The vertical profile of three metals were also measured and was found that except the less change of Cd,the concentrations of copper and lead increased with depth.The main contributions were thought to be the re-suspended particles from surface sediments.The average flux of dissolved Cu,Pb and Cd from Jiulong River to coastal sea were estimated to be about 6.57,6.91,1.47 kg/d separately,while that of particulate phases were 4.66,6.96,0.027 kg/d,separately.Distribution coefficients(Kd) for metals between particulate(>0.45 μm) and dissolved(Pb>Cd in average.The average Kd of Cu,Pb and Cd were 4.09,2.84,0.105 L/kg,separately.The distribution of dissolved and particulate metals in studied area are mainly affected by the operation of the "Particle Concentration Effect",especially for Pb and Cu when salinity was above 11 ‰,while the inverse linear Kd versus salinity relationship for Cd was found when salinity below 11 ‰,which might be due to the operation of the "Salinity Effect".国家自然科学基金(40306012);; 福建省重点科技项目(2005Y021);; 福建省海洋与渔业局科技项目;; 厦门大学科技创新项目资