Heavy metal retention by soil mineral phases during a potential soil contamination by sewage sludge     

《中国地球化学学报》2006,25(B08):194-195

The immobilization conditions of heavy metals （Ni, Cu, Zn, Pb） potentially released from sewage sludge to soils were examined. Competitive adsorption experiments, sequential extraction and analytical electron microscopic studies were performed on soils with different compositional characteristics to gain information about the interaction and association of metals with soil minerals. The results showed that Cu and Pb can be characterized by a preferred adsorption in contrast to Zn and Ni independent of initial metal concentrations, ratios, and soil composition. Precipitation is the dominating retardation process in the sample containing carbonates, but it is also characteristic of metals with inhibited adsorption in samples free of carbonate. Both Cu and Pb show high affinity towards organic matter. Differences in metal affinities towards different clay minerals show the immobilization of Cu rather by specific adsorption and that of Pb rather by ion exchange. According to the sequential extraction studies the role of ion exchange is the most important process for the retardation of Zn, and in the sample containing montmorillonite. The specific adsorption is significant mostly for Cu and Pb, and primarily in samples rich in organic matter and containing vermiculite. The co-precipitation of metals with Fe-Mn oxides is significant primarily for Cu, but in some cases Pb and Zn can be also found in this fraction. In general, the strength of immobilization for the studied metals is as follows： Cu〉Pb〉Zn〉Ni. Significantly higher metal adsorption was found by the phases in the sample containing carbonates, as well as in samples characterized by the close association of clay minerals and iron oxides. Smectite and vermiculite are the most important adsorbents in soils for all of the metals. Additionally, iron-oxides immboilize significant amounts of Cu and Zn, too.  相似文献   

Effect of incubating plant cuticles in soil on their sorptive capabilities     

Benny Chefetz Keren Stimler Baoshan XING 《中国地球化学学报》2006,25(B08):258-258

Sorption and desorption are the major processes influencing the fate of hydrophobic organic compounds （HOCs） in soils. Among the natural sorbents in the environment, soil organic matter （SOM） plays a significant role in the overall sorption of many organic compounds. Recently, several reports have emphasized the role of aliphatic-rich sorbents in the binding of HOCs. The main source of aliphatic compounds for SOM is biopolymers derived from above- and below-ground plant cuticular matter. The plant cuticle is a thin layer of predominantly lipid material that covers all primary aerial surfaces of vascular plants. The objective of this study was to examine the effect of decomposition and transformation of plant cuticles on their sorption behavior with triazine herbicides and polycyclic aromatic hydrocarbons （PAHs）. Sorption-desorption behavior was studied during 12 months of incubation of cuticles isolated from tomato fruits and pummelo leaves in sandy soil. Sorption and desorption experiments and spectroscopic and chemical analyses were performed using the samples after 0, 1, 3, 6 and 12 months of incubation. The decomposition of the cuticles （46-49% after 12 months） did not affect the organic carbon-normalized Freundlich distribution coefficient （KFOC） for the PAHs. In addition, throughout the incubation period, the two PAHs exhibited linear and reversible sorption isotherms with both cuticles. However, the isotherms of the triazines were significantly affected by the decomposition of the cuticles from pummelo leaves, whereas only minor changes were recorded for the tomato cuticle samples. For the microcosm with cuticles from the pummelo leaves, the KFOC values of the triazines increased with increasing decomposition.  相似文献   

Study on the mechanism of transport of heavy metals in soil in western suburb of Beijing     

李宏艳王金生  滕彦国王震宇 《中国地球化学学报》2006,25(2):173-177

1 IntroductionIncorporation of potentially toxic metals ( e.g.Cd, Cu, Cr, Pb, Hg, As, Se, Zn, Ni) into soils ei-ther through sewage-sludge irrigation or some othersources of pollution (e.g. atmospheric deposition, ap-plication of agri-chemicals) has posed…  相似文献   

配合物改性蒙脱石及其对直接大红染料的吸附性     

叶玲  张敬阳  吴季怀 《矿物学报》2007,27(2):121-126

利用蒙脱石的层间活性,用过渡金属离子与配位体生成的配合物改性蒙脱石,通过测定改性蒙脱石对直接大红染料的脱色性及XRD图,研究配合物的中心离子种类、配位体种类、制备方法等对蒙脱石层间结构及吸附较大分子化合物性能的影响。结果表明,带正电的配合物离子能够有效进入蒙脱石层间、增大层间距;4或6配位数的配合物改性蒙脱石能明显提高对染料的吸附性;采用金属离子为先驱体,先插入蒙脱石层间,再原位生成配合物的两步法效果较好。  相似文献   

三角褐指藻对汞吸收富集作用的研究——汞与浮游植物相互作用(Ⅱ)     

吕小乔  孙秉一  史致丽 《中国海洋大学学报(自然科学版)》1990,(4)

采用连续培养方法,研究三角褐指藻对汞(HgCl_2)的吸附富集作用。结果表明,藻体对汞有较大的富集能力,加入培养瓶中的汞被藻体富集率在95％以上,富集因子的变化范围在3×10~4—2×10~5之间。三角褐指藻的吸附符合Freundlich吸附公式,其动力学过程是一级反应。并讨论了胶州湾水体中浮游植物与汞含量间的关系。  相似文献   

厦门西港表层沉积物对铅的吸附作用     

陈松  林汝健 《台湾海峡》1991,10(3):240-244

在海水介质中,模拟研究了厦门西港沉积物对Pb吸附过程的热力学和动力学性质,提出相应的定量模式,测定饱和吸附量、吸附速率常数和表观活化能等重要物化参数。结果表明,沉积物-Pb的吸附以化学作用为主,静电作用为辅。其吸附性质与水合氧化铁-Pb的吸附类似。  相似文献   

淡—咸水界面切换中矿物表面吸附性变化研究   总被引：7，自引：3，他引：4  

吴大清  彭金莲 《地球化学》1999,28(2):155-162

实验研究表明,当电解质离子浓度从有低上升到极高时,矿物吸附金属离子的普遍下降,例外的仅有石英、水云母、ＣａＣＯ３和三水铝矿对Ｐｂ＾３＋、Ｚｎ＾３＋离子的吸 云母对Ｃｕ＾２＋的吸附和石英对Ｃｒ＾３＋的吸附。理论研究表明,一方面,电解质ＮａＣｌ的加入,使矿物表面Ｓｔｅｎ的层电位发生变化,△ψ（ψ０－ψβ）的绝对值增大,提高了矿物表面吸附离子的能力;另一方面,由于Ｎａ离子的竞争吸附和Ｃｌ离子与深液中金  相似文献   

铀酰和镎酰离子在氧化物和硅酸盐表面吸附过程中的金属—配…     

Kolhl.  M 金仁和 《华东地质学院学报》1993,16(2):108-111

  相似文献   

极大螺旋藻富积重金属机理的研究   总被引：16，自引：0，他引：16  

李建宏  曾昭琪  薛宇鸣  邰子厚 《海洋与湖沼》1998,29(3):274-279

于1993年5月由南京大学藻类培养室提供极大螺旋藻藻种,用Zarrouk培养基培养后,用活藻体和甲醛杀死的藻体分别进行吸附实验;过滤出的藻体置于6×10－3g／L左右浓度的Co2+,Ni2+,Cu2+,Zn2+离子混合液中。结果显示,死、活藻体都具有相似的吸附能力,对Co2+,Ni2+,Zn2+的富积大于203倍,对Cu2+的富积大于185倍;用热水提取、DEAE-纤维素D-23柱和SephadexG－200柱纯化后,获得了纯细胞外壁多糖,其分子量为52kD。将该糖溶液盛在透析袋内,并置于4种离子混合液中进行吸附实验,结果显示,核糖对Co2+,Ni2+,Cu2+,Zn2+的富积倍数分别达1744,1644,1340,1750。藻体和多糖对Co2+,Ni2+,Zn2+的吸附都高于对Cu2+的吸附。比较藻体与多糖对4种离子的吸附结果可见,藻体对离子的吸附主要是多糖的作用;多糖的红外光谱显示,金属离子改变OH和CO－NH的吸收峰,表明这两种基团与金属离子发生了络合作用;对Cu2+的络合滴定测定表明,Cu2+与多糖的结合度为0．40。  相似文献   

浅海原油净化过程的模拟实验──悬浮物对油的吸附作用   总被引：2，自引：0，他引：2  

郝恩良  祝陈坚  李铁  石晓勇  于圣睿  王永辰  史致丽  孙秉一 《海洋与湖沼》1998,29(2):156-162

１９８９年３－７月在实验室内采用模拟实验的方法进行黄河口悬浮泥沙对胜利油田的河口油和东营油吸附作用的研究。结果表明,在一定温度下悬浮物对油的吸附符合Ｆｒｅｕｎｄｉｃｈ关系式：Ｑｐ＝Ｋｄ．Ｃ＾ｌ／ｎｗ。  相似文献