Removal of tributyltin (TBT) by live and dead microalgal cells

The removal of tributyltin (TBT) from artificial wastewater by dead and live cells of four microalgal species, Chlorella miniata, C. sorokiniana, Scenedesmus dimorphus and S. platydiscus was investigated. Dead cells were generally more efficient in removing TBT during three days exposure. More than 90% and 85% TBT were removed by dead cells of Scenedesmus and Chlorella, respectively. Although the removal percentages of live microalgae were smaller, TBT was continuously absorbed and degraded, and TBT removal percentages similar to respective dead cells were achieved at the end of 14 days treatment. Degradation products, DBT and MBT, were recorded mainly inside the cells, and intracellular MBT concentrations were significantly higher than DBT. In terms of TBT removal, Scenedesmus cells were more effective than Chlorella, probably due to larger cell sizes and biomass. However, TBT specific uptake and degradation by Chlorella was higher than in Scenedesmus. The highest specific TBT uptake values, as well as the highest degradation, were recorded in C. miniata, a Hong Kong isolate.     

溶解作用对南海北部沉积物捕获器碳、氮通量估算的影响

由于化学溶出、物理溶解以及胞外酶等作用,沉积物捕获器中颗粒物在锚系布放期间会发生一定程度的溶解,从而引起沉积物捕获器中碳、氮颗粒物通量的低估。本文对于1987—1988年南海北部中深层沉积物捕获器中碳、氮颗粒物的溶解作用进行了研究。溶解作用对于碳、氮通量估算的影响大致随着深度的增加而减小。总体而言,颗粒有机碳通量低估约3.8%~40.3%,平均值为26.6%。颗粒氮通量低估约4.2%~76.4%,平均值为43.7%。碳、氮颗粒物的溶出量与颗粒物通量大小关系不明显,但是样品储存时间对于碳、氮颗粒物溶解作用的影响较显著,储存时间较长的样品中颗粒物溶出量更大。     

北极陆架沉积碳埋藏及其在全球碳循环中的作用

陆架边缘海有机碳的堆积速率比大洋高一个数量级 ,全球大约有 80 %以上的沉积有机碳埋藏于陆架地区。北极陆架是世界上最大的陆架 ,占全球陆架面积的 1 / 4 ,然而由于相关的工作较少 ,目前对北极沉积有机碳埋藏情况及其对全球的贡献还知之甚少。北极地区沉积有机碳埋藏主要取决于生物泵 ,而生物泵过程一个主要的限制因子是海冰的覆盖。近几十年来随着全球变暖 ,北极海冰覆盖面积正在快速减小。本文从北极沉积有机碳的来源、河流携带的沉积物输入、海冰覆盖率、营养盐来源等方面初步讨论了陆源输入和生物泵过程对沉积碳来源和埋藏时空变化的影响。结合两次北极考察的初步结果指出 ,全球变暖很可能使北极陆架边缘海成为沉积有机碳的高效汇区。     

Seasonal changes in imposex and tissue burden of butyltin compounds in Thais clavigera populations along the coastal area of Mirs Bay, China

We assessed the current status of tributyltin (TBT) contamination of Thais clavigera (Gastropoda) along the coastal area of Mirs Bay, China for the first time. The snail samples were collected from 10 different sites in the summer (June) and winter (December) of 2006, respectively. They were analyzed for imposex status, i.e. relative penis size index (RPSI) and vas deferens sequence index (VDSI), followed by quantification of butyltins in their tissues. Most of the collected females suffered from imposex, but the level of butyltin contamination varied with the distance from Yantian Port, which is currently the fourth busiest container port in the world. The tissue concentration of TBT varied with season. For a particular site, the winter samples in general contained much higher concentration of TBT than the summer samples. RPSI, VDSI and organotin concentrations were higher in T. clavigera collected from sites closer to the Port, such as the Seafood Street and Kat O. Both RPSI and VDSI were positively correlated with the tissue burden of tributyltin. VDSI exhibited little seasonal variability, whereas RPSI showed marked seasonal variability, with lower values in the summer samples. The current results will serve as an important reference for long-term monitoring of butyltin contamination in this area.     

Effects of salinity on treatment of municipal wastewater by constructed mangrove wetland microcosms

The effects of salinity on the removal of dissolved organic carbon and nutrients from municipal wastewater by constructed mangrove microcosms planted with Aegiceras corniculatum were investigated. During the four-month wastewater treatment, the treatment efficiency was reduced by high salinity, and the removal percentages of dissolved organic carbon, ammonia-N and inorganic N dropped from 91% to 71%, from 98% to 83% and from 78% to 56%, respectively, with salinity increasing from 0 to 30 parts per thousands (ppt). In spite of such inhibition at high salinity, 100% of the effluents discharge from the constructed mangrove microcosms still complied with the discharge standards set by the Hong Kong Government for Coastal Water Control Zones. These results suggested that constructed mangrove wetland treatment systems were promising to effectively treat municipal wastewater, even those with high salinity. In addition, the denitrification potential in soil was found to be retarded by the high salinity while mangrove plants grew best at 15 ppt salinity condition.     

南海北部沉降颗粒氨基酸通量及生物地球化学意义

对1987年9月到1988年10月放置于南海北部的3套沉积物捕获器样品(共39个)进行了氨基酸通量及组成的研究.氨基酸通量与总通量的变化一致,均呈现季节性的不同,并与南海季风有显着关系.氨基酸组合特征及季节性变化指示沉降颗粒有机物质主要来源于海洋浮游生物,其中浅层捕获器浮游植物为主要来源,而深层则浮游动物的贡献大.颗粒物质存在着快速沉降的机制,表明由南海季风气候控制的海洋真光层季节性的物理、化学条件变化引起的生物响应,一定程度上控制着海洋颗粒物质的产生、传输和沉积.     

海水营养盐标准物质的研制和发展

文章分析我国和国际海水营养盐标准物质的研制情况,重点介绍国际海洋标准物质知名组织或机构以及海水营养盐数据全球实验室间比对工作。在此基础上,提出我国海水营养盐标准物质研制的发展方向,主要包括建立海洋标准物质分类和管理体系、建立国家海洋标准物质研制组织或机构、参与海水营养盐数据全球实验室间比对、改进海水营养盐标准物质配制基底和方法以及针对特殊海域研制海水营养盐标准物质5个方面,以期满足海洋环境监测、海洋生物资源开发利用和海洋科学研究的需求。     

河口污染沉积物中重金属释放与迁移的围隔生态系研究

利用围隔式生态实验装置研究了加拿大False河口污染沉积物中重金属Pb、Zn、Cd、Cu在海水环境中的行为。实验模拟了 4种环境条件 :( 1)高生产力 ;( 2 )低生产力 ;( 3 )高悬浮物含量 ;( 4 )还原环境。结果表明 ,污染沉积物中重金属在海水环境中的行为既取决于元素自身性质 ,亦受外界环境条件制约。还原环境能抑制重金属的释放 ,有助于体系中原有的重金属清除出水柱。低生产力条件下 ,Pb、Zn表现出释放行为 ,而高生产力和高悬浮物含量条件下 ,Pb、Zn表现出先释放后迁移 ,而Cd、Cu则呈现出相反的图象。研究了实验期间 4种重金属释放与迁移的净通量 ,表明氧化条件下Cu、Zn净释放通量比Cd、Pb高 1～ 2个量级。研究表明 ,添加粘土及向还原环境倾倒均有助于减轻污染沉积物倾倒后重金属的二次污染     

南海若干古生产力替代指标探讨

沉积记录中的古环境信息,是经过各种复杂的生物地球化学过程改造后的信号,因而是不完整的,有些甚至可能是被歪曲的。通过表层沉积有机碳、生物硅和色素对上层海洋的响应,对南海古生产力替代指标的可靠性及其影响因素作出初步评估。尽管南海海洋生产力较低,生源通量以小颗粒为主(沉降速率慢),侧向漂移明显,且不易形成低氧条件,使有机碳的保存效率比较低,影响了沉积有机碳作为古生产力替代指标的可靠性,但南海表层沉积有机碳含量在大的时空尺度上仍然能反映上升流高生产力区状况,说明沉积记录(几十至几百年时间尺度)对小尺度(自季至年)上的"细节"差异可以进行"平滑"。总的来说,沉积有机碳是比较好的古生产力指标,但对于寡营养、生物群落结构时空变化大、碳酸盐溶解和陆源稀释影响明显的南海,将绿素和生物硅含量作为古生产力替代指标时应该更加慎重。     

海气交换与呼吸作用调控下杭州湾碳酸盐体系的特征

杭州湾作为典型的高浑浊度海湾,对其水体碳酸盐体系分布特征的研究相对较少.本文基于两个夏季航次(2018年和2019年)获取的调查资料,阐述夏季杭州湾水体中碳酸盐体系参数的空间分布特征,并进一步分析影响溶解无机碳偏离保守混合作用的主要过程及相对贡献.数据结果表明,杭州湾内表层溶解无机碳浓度与总碱度的变化范围分别为1553...