基于水淘选分级的长江口及邻近海域表层沉积物中磷的形态分布和迁移转化     

刘慧  姚鹏  孟佳  王金鹏  赵彬 《海洋学报》2017,39(8):115-128

磷是一种重要的生源要素,在河口、边缘海的初级生产中发挥重要作用,了解沉积物中磷的形态分布和迁移转化有助于深入了解该区域生态系统动力学。于2013年3月在长江口及邻近海域采集了表层沉积物样品,利用水淘选方法对沉积物进行了分级,并采用化学连续提取法分析了未分级和分级沉积物样品中的6种磷形态含量:可交换态磷、活性有机磷、铁结合态磷、自生磷灰石磷、碎屑磷和难分解有机磷,讨论了该区域沉积物中磷的形态分布、选择性输运过程和迁移转化。沉积物中总磷含量在14.0~18.4 μmol/g,其中碎屑磷是其主要成分,占54.5%,其次是有机磷和难分解有机磷,分别占到15.1%和13.1%。不同粒级沉积物中磷形态含量不同,可交换态磷、活性有机磷、铁结合态磷、自生磷灰石磷和难分解有机磷随粒级增加含量逐渐降低,而碎屑磷主要集中在粗粒级（大于32 μm）沉积物中。基于各粒级磷形态的质量分布,发现小于32 μm粒级的沉积物中各磷形态含量从长江口向浙闽沿岸逐渐增加,向外海方向逐渐减小,而大于32 μm沉积物的变化趋势与此相反,体现了不同形态磷的选择性输运。随粒径增大,总有机碳对有机磷比值（TOC/Or-P）先降低后升高,在大粒级沉积物中,TOC/Or-P比值较高主要是因为陆源有机碳贡献较高,而在小粒级沉积物中,主要是由于有机磷的迁移和转化更为活跃,体现了细颗粒物中有机磷相对有机碳的优先分解。本研究表明,从分级的角度可以对河口、边缘海的磷循环有一个更全面的认识。  相似文献   

土壤重金属连续提取方法的优化   总被引：2，自引：0，他引：2  

刘丹丹  刘菲  缪德仁 《现代地质》2015,29(2):390-396

重金属在污染土壤中的形态分布决定着重金属的迁移性和危害的程度。土壤重金属形态分析应用最多的是Tessier和BCR连续提取法。Tessier和BCR连续提取法没有考虑土壤样品的特征。美国环保署危险废物浸出毒性鉴别标准法虽然考虑土壤pH值,但没有划分形态。采集不同pH土样,结合Tessier、BCR和毒性浸出鉴别方法的特征,优化出针对不同pH值土壤的连续提取方法,将土壤中重金属划分为活性态、次生碳酸盐结合态、次稳定态和稳定态。用优化的连续提取方法对土样进行连续提取,重金属回收率为85%~115%。优化连续提取方法的结果与Tessier和BCR结果对比显示优化连续提取方法克服了Tessier连续提取法对非石灰质土壤提取过量BCR连续提取法对石灰质土壤提取不足的缺点。优化后的连续提取方法数据稳定可靠,可作为重金属形态分析方法使用。  相似文献   

Source speciation resolving hydrochemical complexity of coastal aquifers     

《Marine pollution bulletin》2014,78(1-2):118-129

There is a growing concern of seawater intrusion to freshwater aquifers due to groundwater overexploitation in the eastern coastal belt of Southern India. The problem becomes complex in the regions where industrial effluents are also contaminating the freshwater aquifers. In order to understand the hydrochemical complexity of the system, topographic elevation, static water level measurements, major ion chemistry, ionic cross plots, water type contours and factor analysis were applied for 144 groundwater samples of shallow and deep sources from Quaternary and Tertiary coastal aquifers, located within the industrial zone of 25 km² area near Cuddalore, Southern India. The ionic cross plots indicates dissolution of halite minerals from marine sources and seawater mixing into inland aquifers up to the level of 9.3%. The factor analysis explains three significant factors totaling 86.3% of cumulative sample variance which includes varying contribution from marine, industrial effluent and freshwater sources.  相似文献   

浙江富硒土壤资源调查与评价   总被引：26，自引：0，他引：26       下载免费PDF全文

郦逸根  董岩翔  郑洁  李琰  吴小勇  朱朝晖 《第四纪研究》2005,25(3):323-330

浙江省农业地质环境调查发现,浙北、浙东、浙中地区富硒土壤呈大面积分布。不同类型土壤中,以石灰岩土硒含量最高,黄壤和红壤硒含量次之;不同类型成土母质中,以残坡积物硒含量相对较高;不同类型岩石中,以石英砂岩、硅质岩和中深变质岩硒含量较高,高于中国东部地壳丰度值。富硒土壤主要分布于富硒岩石和煤系地层区。硒多富集在土壤表层,由地表向深部含量迅速下降。根据土壤背景值和硒生态景观分级标准,建立了富硒土壤评价标准,划分硒含量等级区,圈定了浙江省富硒土壤分布。  相似文献   

ANC,BNC and mobilization of Cr from polluted sediments in function of pH changes     

A. Shtiza  R. Swennen  V. Cappuyns  A. Tashko 《Environmental Geology》2009,56(8):1663-1678

During the manufacturing of chromate salts (1972–1992) large quantities of Chromite Ore Processing Residue (COPR) were released into a decantation pond east of the former chemical plant of Porto-Romano (Durres, Albania), giving rise to yellow colored pond sediments. These Cr(VI) bearing sediments were deposited upon Quaternary silty-clay lagoonal sediments rich in iron oxides and organic matter. The pH values in these lagoonal sediments vary around 6.6, while in the pond sediments, it is mainly acidic (due to the presence of the sulfur stock piles in the area and the release of the H₂SO₄ from the activity of the former chemical plant), varying between 1.4 and 3.8. Continuous leaching of the COPR waste resulted in yellow-colored surface water runoff. The prediction of pH changes in the different types of sediments based upon acid/base neutralizing capacity (ANC/BNC) jointly with the quantitative data on release of heavy metals and especially Cr is considered an important advantage of the pH_stat leaching test if compared to conventional leaching procedures. Thus, factors controlling the leaching of Cr(VI), Cr(III), Ca, Al, Fe, Mg from the COPR were investigated by means of pH_stat batch leaching tests and mineralogical analysis. Moreover, mathematical and geochemical modeling complemented the study. The COPR in the area contain very high concentrations of chromium 24,409 mg/kg, which mainly occurs as Cr(III) (75–90%) as well as Cr(VI) (25–10%). The leaching of Cr(VI) occurs in all the range (2–10) of the tested pH values, however, it decreases under acidic conditions. Beside some reduction of Cr(VI) to Cr(III), the Cr(VI) content of the leachtes remains relatively high in the acidic environment, while the limning of Cr(VI) pond sediments will increase the release of the latter specie. The leaching of the Cr(III) occurs strictly under acidic conditions, whereby limning of these sediments will give rise to the lower solubility of Cr(III). The key mineral phases responsible for the fast release of the Cr(VI) are: the chromate salts (i.e. sodium chromate and sodium dichromate), while sparingly soluble chromatite (CaCrO₄) and hashemite (BaCrO₄) release Cr(VI) very slowly. Thus, pH and mineral solubility have been identified as key factors in the retention and the release of the hexavalent CrO₄ ²⁻ and Cr₂O₇ ⁻ from the COPR-rich pond sediments.  相似文献   

Contamination,chemical speciation and vertical distribution of heavy metals in soils of an old and large industrial zone in Northeast China   总被引：5，自引：0，他引：5  

Fayun Li  Zhiping Fan  Pengfei Xiao  Kokyo Oh  Xiping Ma  Wei Hou 《Environmental Geology》2009,57(8):1815-1823

Heavy metal pollution of soils has become a major concern in China as a consequence of rapid urbanization and industrialization in recent years. However, the evaluation on soil heavy metal pollution in Shenyang, the largest heavy industrial base city in China, has not yet been conducted. In this study, accumulation, chemical speciation, and vertical distribution Cu, Zn, Pb and Cd in soils were studied and pollution condition was assessed in Tiexi Industrial District of Shenyang, the largest and oldest industrial zone in Northeastern China. The results showed that in topsoil, the average concentration of total Cu, Zn, Pb, and Cd was 209.06, 599.92, 470.19 and 8.59 mg kg⁻¹, respectively, much higher than the national threshold limit. The values of pollution index and integrated pollution index showed that the pollution level was Cd > Cu > Zn > Pb, and Cd, Cu and Zn belong to heavy pollution level. The residual, Fe and Mn oxide-bound, and organic-bound species accounted for about 90%, while carbonate-bound and exchangeable species accounted for about 10%. This study indicates that the soils in the industrial zone were widely and extremely polluted by multi-heavy metals as a result of long-term industrial activities.  相似文献   

太湖沉积物中重金属的地球化学形态及特征分析   总被引：24，自引：2，他引：22  

袁旭音  王爱华  许乃政 《地球化学》2004,33(6):611-618

用连续提取法分析了太湖沉积物5种重金属的地球化学形态,对地球化学形态的组成和地理特征进行了分析研究.重金属地球化学形态配分的共同特点是可交换态最低,残渣态最高.两种形态中Cd的可交换态最高,Cr的残渣态最高,可交换态最低.Cd的碳酸盐态较高,Cr的最低;Pb、Cd的Fe-Mn氧化态较高,Cu的偏低;Cu的有机态最高,Cd的最低;Zn的地球化学形态比例大都处于中间.地域上变化较大的元素是Cd和Cu,变化不明显的元素有Pb和Zn.化学成分中Fe2O3、MnO与重金属地球化学形态的相关性最好,TOC与Cu的形态相关系数最高.综合对比分析表明,太湖沉积物重金属的生物有效性以Cd为最高,其次为Pb.  相似文献   

粉末压片-X射线荧光光谱法分析富硒土壤样品中的硒及主次量元素   总被引：1，自引：0，他引：1  

李迎春  张磊  尚文郁 《岩矿测试》2022,(1):145-152

目前土壤中Se主要采用原子荧光光谱法测定,存在用酸量大、前处理相对复杂等缺点,对于高含量Se的测定则需要高倍稀释,无疑会扩大分析误差.本文采用粉末压片波谱-能谱复合X射线荧光光谱法测定湖北富硒土壤样品中的Se等17个主次量元素,波谱分析10个元素的同时,能谱分析As、Cu、Rb、Sr、Zr、Ba、Ni等7个元素,大幅节...  相似文献   

西北冰洋表层沉积物中重金属的赋存形态研究   总被引：1，自引：0，他引：1  

杨丽  高爱国  张延颇  赵冬梅 《台湾海峡》2012,31(4):451-458

用连续提取法对选自西北冰洋的32个表层沉积物进行分析,测定了Cr、Cu、Pb在全样中及其在P1-2、P3、P4、P5中的含量.结果表明随着离岸距离增加,水深加深,Cr、Cu、Pb含量呈增高的趋势.研究区陆架沉积物中Cr、Cu、Pb含量分别为60.66、14.77、16.65μg/g;深海沉积物中Cr、Cu、Pb的含量分别为80.40、41.70、25.62μg/g.元素赋存形态分析表明,Cr、Cu、Pb主要赋存在残渣态,残渣态中三元素的含量平均值分别为64.97、19.67、17.56μg/g,占元素总量的比例分别为93.58%、75.02%和83.76%.三元素在各赋存形态中的含量分布是:Cu为残渣态>有机质和硫化物态>铁锰氧化态>可交换及碳酸盐态;Pb和Cr则为残渣态>铁锰氧化物态>有机质硫化物态>可交换态及碳酸盐态.研究区重金属元素在不同赋存形态中的含量分布与北太平洋深海沉积物中类似.  相似文献   

Phosphorus Runoff Losses After Application of Organic Waste          下载免费PDF全文

Marta García‐Albacete  María Isabel Requejo  María Carmen Cartagena 《洁净——土壤、空气、水》2016,44(12):1628-1635

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