长江口柱状沉积物中磷的存在形态及其分布特征研究

对长江口的柱状沉积物进行了总磷测定,并运用SEDEX方法分析了长江口柱状沉积物中5种形态磷的含量和分布。研究结果表明,柱状样沉积物不同站位各种形态磷的垂直分布各不相同,由表至底呈现多种分布状态,与沉积环境、沉积后的成岩作用有关。长江口柱状样沉积物有机磷的降解速率常数变化结果表明,长江口海域有机磷的降解主要发生在沉积物表层和次表层。2个柱状样沉积物中氮磷比远低于16∶1,说明长江口近岸海域沉积物中的磷主要来自陆源。对柱状样的年代分析表明,总磷含量随年代的变化有明显的区域特征性,长江口总磷含量的髙值与长江较大输沙量的年份具有一致性。浙江省环保科研计划项目(2008-30

Geochemical characteristics of nitrogen in the core sediments from Changjiang River Estuary

研究分析了长江口柱状沉积物中氮的赋存形态,并结合沉积速率和有机碳含量分析了氮的迁移转化特征和有机质来源。研究结果表明,有机物与硫化物结合态氮(OSf-n)是柱状样可转化形态氮中的主要赋存形态,碳酸盐结合态氮(Cf-n)含量最低;位于长江口122°E附近测点的各形态氮的垂直分布与122.6°E附近测点的差异明显,受水动力条件和沉积速率等因素影响,122.6°E附近测点的有机氮降解速率常数和各形态氮的埋藏通量均高于122°E附近测点;长江口柱状沉积物中有机氮降解主要发生在沉积物表层和次表层;OC/Tn值的垂直分布变化幅度较大,陆源输入均大于70%。Total nitrogen and its forms in the core sediments from Changjiang River Estuary were studied with sequential extraction method.And combined with the deposition rate and the organic carbon content,the characteristics of its migration and transformation and the sources of organic carbon were also studied.The results show that OSF-N is the main form of transferable nitrogen,and CF-N content is the lowest of the transferable nitrogen in the core sediments.There are evident differences in the vertical distribution of different nitrogen forms in the core sediments of SH3111 station(at 31°N,122°E) from that in SH3110 station(31°N,122.6°E).Affected by the hydrodynamics and the deposition rate,the values of the degradation rate constant of the organic nitrogen and the burial flux of different forms of nitrogen at the SH3110 station are higher than those at the SH3111 station.Degradation of the organic nitrogen occurred mainly in the surface and sub-surface layers of the sediment and the vertical distribution of the OC/TN ratios varies greatly,showing different depositional conditions.The proportions of terrigenous carbon are higher than 70%.环保公益性行业科研专项资助项目(2008467041);浙江省环保厅科研专项资助项目(2008-30

Nitrogen forms and their concentration distribution in surface sediments of Zhejiang offshore

运用分相浸取法分析了浙江近岸海域60个站位的表层沉积物(0~2 CM)中各形态氮的含量和分布.研究结果表明,表层沉积物中总氮(Tn)含量为214.66~861.44 Mg/kg,均值为580.52Mg/kg,位于浅水区的长江口、杭州湾和浙江沿岸的Tn含量低于东部远岸海域;可转化态氮(TTn)含量只占总氮的3.06%~37.24%,有机态和硫化物结合态氮(OSf-n)是沉积物中可转化态氮的主要赋存形态,非转化态氮(nTn)是浙江近岸海域表层沉积物中的优势形态.各站位沉积物中氮在不同提取相中的含量差异较大,与沉积物的陆源输入、沉积物重金属含量、粒径分布及沉积海域的水动力条件等因素有关.Different forms of nitrogen in surface sediments of Zhejiang offshore were studied with sequential extraction method.The result show that total nitrogen concentration in offshore surface sediments of Zhejiang ranged from 214.66 to 861.44 mg/kg with an average 580.52 mg/kg,and the concentration of TN was found higher in the eastern offshore of Zhejiang than Changjiang Estuary,Hangzhou Bay and Zhejiang coastal area.Transferable nitrogen,accounting for least part of total nitrogen,varied from 3.06% to 37.24%.Organic matter-sulfide form(OSF) is the dominant form of transferable nitrogen while non-transferable form is the dominant form in the surface sediments.Distribution of nitrogen forms is controlled by environmental factors,such as terrigenous inputs,grain size,heavy metal contents in surface sediments and hydro-dynamics.国家环保部公益科研专项资助项目(2008467041);浙江省环保厅科研专项资助项目(2008-30

Study of Chemical Forms of Phosphorus and Their Distributions in the Surface Sediment in Zhejiang offshore

运用SEdEX方法分析了浙江近岸海域表层沉积物中总磷(TP)及磷在各提取相的含量和分布.研究结果表明,表层沉积物中TP含量为432.2~846.1Mg/kg,平均为(533.2±90.1)Mg/kg;弱吸附态磷(AdS-P)、铁结合态磷(fE-P)、自生磷灰石及钙结合态磷(CA-P)、碎屑态磷(dE-P)和有机磷(OP)平均含量分别为6.2,93.2,12.4,295.0和66.5Mg/kg,分别占TP的1.2%,17.7%,2.4%,56.7%,和12.7%.沉积物的AdS-P、CA-P和OP与其粒度和有机碳含量呈显著正相关,dE-P则呈负相关.各站位沉积物中磷在不同提取相中的含量差异较大,与沉积物的陆源输入、沉积物粒径及沉积海域的水动力条件等因素有关.Total phosphorus and its related forms in the surface sediment in Zhejiang offshore were studied by SEDEX method.The results showed that the content of total phosphorus(TP) in the surface sediment was 432.2-846.1 mg/kg,and average content was(533.2±90.1) mg/kg,and the average content of weakly absorbed phosphorus(Ads-P),iron phosphorus(Fe-P) calcium phosphorus(Ca-P),detritus phosphorus(De-P) and organic phosphorus(OP) were 6.2,93.2,12.4,295.0 and 66.5 mg/kg,respectively,and the percentage composition of TP were 1.2%,17.7%,2.4%,56.7% and 12.7%,respectively.The content of different forms of phosphorus in different sites was mainly influenced by terrigenous inputs,sediment grain size and hydro-dynamics.There are significant positive correlations between sediment grain size,organic carbon and Ads-P,Ca-P,OP;and negative correlations between sediment grain size,organic carbon and De-P.浙江省环保科研计划项目(2008-30

Optimizing Catalyst Layer Composition of PEMFC by Orthogonal Method

　利用正交实验设计法优选PEMFC电极催化层制备的最佳条件.实验证实亲水电极(催化层中不含PTFE)性能优于疏水电极.在该工艺条件下,当Nafion的含量为1.4mg·cm-2,Pt含量为0.4mg·cm-2时,以常压的H2和空气分别作为燃料气和氧化剂,电池的最高功率可达到0.37W·cm-2.研究表明,提高Pt/C中的Pt含量将是提高催化剂性能的有效途径.The optimal composition of catalyst layer in a PEMFC electrode was studied through orthogonal method. It was showed that the performance of hydrophilic electrodes, in which there is no PTFE in the catalyst layer, were more favorable than that of hydrophobic electrodes. According to this condition, the power density of PEMFC attained 0.37 w·cm-2 when the Nafion loading was 1.4 mg·cm-2, and the Pt loading was 0.4 mg·cm-2 in the catalyst layer, using H2 as fuel and air as oxidant both at atmospheric pressure. Additionally, the results showed that increasing Pt loading in Pt/C catalyst was a reasonable way to improve PEMFC performance.作者联系地址：上海交通大学燃料电池研究所,上海交通大学燃料电池研究所,上海交通大学燃料电池研究所,上海交通大学燃料电池研究所,上海交通大学燃料电池研究所,上海交通大学燃料电池研究所,上海交通大学燃料电池研究所 上海200030 ,上海200030 ,上海200030 ,上海200030 ,上海200030 ,上海200030 ,上海200030Author's Address: Institute of Fuel Cell,Shanghai Jiao Tong University,Shanghai 200030,Chin