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1.
以胶州湾海泊河口和李村河口为对象,研究了其沉积物中的汞向海水的释放.结果表明,在静态条件下,沉积物汞向海水释放,平衡时海泊河口和李村河口沉积物汞的释放量分别为 0.070 5 ～ 0.117 μg/g 和 0.056 5 ～ 0.093 5 μg/g;汞的释放通量在前 2 h 最大,随后逐渐减小,通量与温度呈指数正相关.通过对汞释放的热力学分析,汞释放的反应热大于零,分别为 9.92 kJ·mol-1 和 9.98 kJ·mol-1,说明汞的释放是一个吸热过程;汞的释放是一个熵增过程;两个实验反应的标准自由能变分别为 2.34 ～ 3.22 kJ·mol-1和 1.19 ～ 2.20 kJ·mol-1,而且温度越高,ΔG0 越小,越利于反应向正方向进行. 相似文献
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选取胶州湾海域2个站点的沉积物进行了表面酸碱电位滴定实验,并考察了人工海水介质中对铜离子的吸附性能,比较了介质的盐度和温度等对吸附动力学曲线和吸附等温线的影响。结果发现:2个站点的沉积物随pH值由3增大到10表面质子电荷密度的值由正转负,零净质子电荷点pHPZNPC均在4.0～4.5之间,表面位浓度HS在1.34×10-4～1.90×10-4mol.L-1之间;沉积物对铜离子的动力学吸附曲线可用伪一级动力学方程、伪二级动力学方程、Elovich方程、双常数速率方程拟合,其中伪二级动力学方程符合较好,吸附在2 h左右达到平衡;吸附等温线可用Langmuir等温式拟合。零净质子电荷点低、表面位浓度大的沉积物对铜离子的吸附能力较强。蒸馏水介质中,沉积物对铜离子的饱和吸附量小于在稀释人工海水中和人工海水中的结果;较高的温度使饱和吸附量增大。 相似文献
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选取胶州湾海域2个站点的沉积物进行了表面酸碱电位滴定实验,并考察了人工海水介质中对铜离子的吸附性能,比较了介质的盐度和温度等对吸附动力学曲线和吸附等温线的影响.结果发现:2个站点的沉积物随pH值由3增大到10表面质子电荷密度的值由正转负,零净质子电荷点pHPZNPC均在4.0～4.5之间,表面位浓度Hs在1.34×104～1.90×10-4 mol·L-1之间;沉积物对铜离子的动力学吸附曲线可用伪一级动力学方程、伪二级动力学方程、Elovich方程、双常数速率方程拟合,其中伪二级动力学方程符合较好,吸附在2h左右达到平衡;吸附等温线可用Langmuir等温式拟合.零净质子电荷点低、表面位浓度大的沉积物对铜离子的吸附能力较强.蒸馏水介质中,沉积物对铜离子的饱和吸附量小于在稀释人工海水中和人工海水中的结果;较高的温度使饱和吸附量增大. 相似文献
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根据1985年4月、7月和10月胶州湾水域调查资料,研究和分析胶州湾重金属汞的水质、平面分布、垂直分布、季节变化以及来源。结果表明:汞在胶州湾水体中的含量范围为:0.029~4.950μg/L,符合一类到劣四类海水水质标准;4月,在胶州湾整个湾内水域受到汞的污染,在湾的东部和北部近岸水域受到汞的严重污染,7月,受到汞的污染较重,在10月,受到汞的轻微污染。胶州湾汞含量只有一个来源:是由海泊河、李村河和娄山河的河流输送的,而且输送的汞浓度都非常高。汞表、底层分布的时空变化和垂直分布都表明了汞迅速沉降的重力特性,证实了汞的水域迁移过程和水域迁移机制。在胶州湾的整个湾内水域,受到汞的污染程度是由河流输送汞含量的多少来决定的。 相似文献
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根据胶州湾海水和表层沉积物样品中重金属含量的分析，探讨了胶州湾的污染现状和发展趋势。将海水和表层沉积物中的重金属含量与该区周边岩石的重金属含量及国家环境标准对比研究表明，胶州湾海水中Cu和Cd含量符合国家一类海水标准，Pb的污染最为严重。胶州湾东部表层沉积物中的Cd、Hg、Pb的含量均超过一类沉积物的国家标准。其主要污染区位于大港至李村河口一带，污染源主要来自陆源污染物，并由河流排出入海所致。胶州湾中部的重金属含量低于国家标准，说明环境状况良好。 相似文献
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研究与探讨了胶州湾李村河河口区3个采样点表层沉积物中磷酸盐释放行为及盐度、温度、波浪强度、悬浮物浓度对磷酸盐释放动力学过程的影响。认为磷酸盐释放的动力学过程大致可分为3个阶段:①0～1h快速释放阶段;②1～8h缓慢释放阶段;③8h之后的平衡阶段。盐度升高可以促进磷酸盐释放,当盐度从0升高到10时,磷酸盐释放量增幅最大,说明磷酸盐释放对水相盐度的突变有较强的敏感性。温度升高有利于磷酸盐释放,在低温(<10℃)和高温(>20℃)条件下磷酸盐释放的过程有明显差异;温度较低时快速释放速率与缓慢释放速率相当,而温度较高时快速释放速率是缓慢释放速率的10倍。波浪强度对磷酸盐释放过程的影响与温度类似,当沉积物处于充分悬浮状态时,磷酸盐释放量会有大幅度提高;当悬浮物浓度降低时,快速释放速率与缓慢释放速率都有大幅度提高,释放总量也显著增加。 相似文献
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粤东柘林湾表层沉积物的汞和砷研究 总被引：12，自引：0，他引：12
2002年8、9月对柘林湾进行了2个航次的沉积物调查,测定了采自9个站位18个表层沉积物样品中的汞、砷含量,并对其来源和分布特征进行了分析。结果表明,调查海区汞的平均含量为0.055±0.020μg·g-1,砷的平均含量为12.23±1.83μg·g-1,与广东省土壤背景值接近。汞与总有机质的相关性较差,与其它海区的研究结果相异。认为大规模海水养殖业的存在是造成这一现象的主要原因。以中国海岸带和海涂资源综合调查报告中的标准对柘林湾表层沉积物的汞、砷含量进行评价,结果均未超标,但养殖过程对汞甲基化和砷释放作用的促进应引起重视。 相似文献
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厦门港湾潮间带沉积物中汞的赋存形态及其释放动力学 总被引：2，自引：0，他引：2
所研究的沉积物样品采自福建省厦门市的港湾潮问带地区,选择了10μg／dm’的汞标准使用液对采集回来的沉积物样品进行了预污染处理,利用预污染后的沉积物样品,在实验室中进行了一系列的汞释放动力学实验．实验结果表明,汞的释放量较低,达到释放平衡时的释放量小于5μg／kg,释放过程可分为2个阶段：前8h为快速释放阶段,之后为慢速释放阶段,大约在24h达释放平衡．采用了Tessier五步提取法对未污染过的沉积物原样及进行过预污染处理的沉积物样品进行了汞的形态分析,结果表明通过污染实验吸附到沉积物上的汞的各形态含量大小顺序为：HgS为主的惰性汞〉单质汞〉盐酸溶无机汞及甲基汞〉有机结合、螯合态汞〉水溶态、交换态等活性汞． 相似文献
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Environmental impact factors and mercury speciation in the sediment along Fujian and eastern Guangdong coasts 总被引：1，自引：0，他引：1
ZHANG Yuanbiao HUO Yunlong LIU Xiyao KUANG Weiming YUAN Dongxing JI Weidong 《海洋学报(英文版)》2013,32(2):76-80
Concentrations of total mercury (THg) and methyl mercury (MeHg) were determined for 32 surface sediments collected along the coastal line of Fujian Province and eastern Guangdong Province. The spatial distributions of THg and MeHg and their environmental impact factors were investigated. The average concentrations of THg and MeHg in the sediments were 31.5 ng/g and 0.096 ng/g, respectively. Both sediment THg and MeHg concentrations showed relatively high value in the Minjiang Estuary and the coastal areas of Quanzhou and Putian. The concentrations overall decreased as the distance to the shoreline increased. The correlations among environmental impact factors and THg, MeHg were analyzed. The sediment THg concentration was highly correlated to the concentrations of organic matter, copper, total nitrogen (TN) and total phosphorus (TP), and significantly correlated to pH value of the bottom seawater and concentration of sediment sulfide. The sediment MeHg concentration was highly correlated to the concentrations of organic matter and copper, and significant correlated to the concentrations of sulfide, TN, TP and pH value of the bottom seawater. 相似文献
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测试研究了胶州湾近岸李村河、海泊河入海口沉积物中氮、磷及重金属含量,以石老人近岸沉积物作为对照,对其污染状况与该生境半知菌种群数量及多样性进行了统计分析.结果表明:李村河与海泊河入海口重金属综合污染指数分别为3.64和1.75,分别为对照区的23.59倍和10.58倍;李村河入海口总氮、总磷平均值分别为对照区的1.73倍和1.33倍;海泊河入海口总氮、总磷平均值分别为对照区的1.44倍和1.98倍;李村河入海口综合污染最为严重.沉积物中可培养半知菌数量随着污染程度(污染指数)增加而减少,这种变化与重金属污染的相关性较强,在一定的变化范围内,重金属综合污染指数增大时,半知菌多样性指数也相应增大,但达到一定程度时,半知菌多样性指数会迅速下降接近为0.氮磷的变化只对半知菌部分种群的数量产生影响,对半知菌整体的数量以及多样性的影响不明显. 相似文献
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本文报道了５套泥沙捕集器在１９８７年８月１３－１７日和１９９０年２月２２－２６日期间在长江口北槽航区域现场投放和观测，集沙杯由有机玻璃制成，内径为５ｃｍ，杯高２１ｃｍ。对在小风情形，小风转大风情形和寒潮大风情形下集沙杯捕获沙样的干重和沙样的中值粒径垂直分布的特征分别作了描述，阱而为大风浪引起航槽游积及其底沙粗化提供了确凿证据。 相似文献
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Sediment input to SMB appears to be associated with at least two point sources on the shelf, with Malibu Creek and the Hyperion sewage outfall being the most significant. Sediment contributions are sufficient to support apparent mass accumulation rates near these sources up to approximately 1.8 g/cm(2) year, which with distance decrease to approximately 0.5 g/cm(2) year near the shelf break (approximately 80-100 m water depth). Sequestering of material on the shelf and decreasing sediment supply to the slope is evident as rates decrease between 100 and 200 m water depths to less than 0.2 g/cm(2) year. Below 100-200 m water depth, rates are relatively slow throughout a broad region of the slope (0.07-0.14 g/cm(2) year). These slower rates are in general agreement with rates determined on the flanks of the California Borderland basins. Sediment texture fines from approximately 3.5 phi to approximately 7 phi with distance offshore. Texture does not exhibit significant changes from surficial values with depth in the seabed at any given site or between sites on the slope. This similarity in rates and downcore texture over such a broad extent suggests that hemiplegic sedimentation is the dominant mechanism of sediment delivery in water depths >200 m. Seabed distributions of radionuclides suggest that apparent accumulation rates in SMB may be twice the actual accumulation rates. A sediment budget documents that over the past century at least, SMB has served as a sink for 50-100% of the natural and anthropogenic inputs to the coastal ocean. 相似文献
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胶州湾大沽河口潮间带沉积物中叶绿素和有机质含量的季节变化 总被引：1，自引：0，他引：1
为了解胶州湾大沽河口潮间带沉积物中底栖微藻和有机质含量的季节变化,于2010年4月至2011年2月,分4次(春、夏、秋、冬)测定分析了沉积物中的叶绿素含量和有机质含量,并分析了沉积物的粒度组成及现场温度。结果表明,表层(0～2cm)沉积物叶绿素a含量为0.42～6.06mg/kg,有机质含量为0.48%～3.71%;次表层(2～5cm)叶绿素a含量为0.13～3.53mg/kg,有机碳质量为0.31%～3.78%;深层(5～8cm)叶绿素a含量为0.14～1.95mg/kg,有机质含量为0.47%～3.72%。经统计检验和Pearson相关性分析得出,胶州湾大沽河口沉积物中的叶绿素a含量春冬两季最高,夏季和秋季最低;叶绿素a含量与深度和温度呈负相关;与所处潮带、有机质含量、粉砂黏土含量在本实验中均无显著的相关性;有机质含量与季节关系不大,高潮带最高,其含量与粉砂黏土含量呈正相关,与叶绿素含量、深度和温度关系不明显。 相似文献
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Seventy-nine total-mercury analyses of seawater samples, collected from the surface down to 5,700 m depth in the northeastern Pacific Ocean and in the South Polar seas, showed a homogeneous distribution of mercury with depth at all stations, although its absolute concentration in the northeastern Pacific (12–30 ng/kg) was 3 to 5 times less than that in the polar waters (50–150 ng/kg). The high concentrations are ascribed to an input of mercury resulting from submarine volcanism.The mercury content was also determined in 8 surface-film samples, 3 sediment cores (0–30 cm), 2 pack-ice samples and 1 sample each of snow and sea smoke. 相似文献
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Sediment cores were collected from the subaqueous delta of the Changjiang Estuary. Sediment grain-size profiles and their fractal dimensions were analyzed, to elucidate responses to long-term sedimentary processes. In addition, the environmental sensitive populations of grain size have been extracted. The sediment cores can be divided into two parts, according to the sedimentary structures present. The upper part (0-12 cm) is interpreted as being the active layer, which is influenced frequently by changes i... 相似文献
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钱塘江河口细颗粒泥沙絮凝沉降特性研究 总被引：3，自引：0，他引：3
钱塘江口河口上游河流和海域来沙多为细颗粒泥沙,粘性细颗粒泥沙由于其特殊的表面电化学性质遇到强电解质海水而产生絮凝沉降,是形成河口淤积的原因之一。影响絮凝的因素很多,除了电解质,还有泥沙粒径的大小、盐度、含沙量、PH值、温度、有机质含量、矿物成分、水流速度及紊动情况等。本文通过粒度分析、静水沉降、动水沉降等各种实验手段分析钱塘江口泥沙的基本特性,找出最佳絮凝盐度以及泥沙不淤流速等值,初步探讨了细颗粒泥沙的絮凝机理,为治理钱塘江口提供科学依据。 相似文献
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Horizontal and vertical distributions of mercury were determined in seawater in Minamata Bay and Yatsushiro Sea. The concentrations of total and particulate mercury respectively ranged from 56–285 ng l–1 and 2.1–506 ng l–1. They were both highest in the inner most part of Minamata Bay where the sediment was most heavily polluted, and decreased with increasing distance from there. Vertically, an evident increase in concentration was observed near the bottom. A good agreement was found between the mercury content in suspended matter and that in fine sediment particles.These facts show that the particulate mercury is supplied mostly from the bottom sediment, and that it is spreading offshore with dispersing in seawater. This process would eventually result in the pollution of sediment in Yatsushiro Sea. 相似文献