Study of Adsorption Isotherm Curves of Amino Acids on the Kaolinite

This paper studies the adsorption isotherm curves of four amino acids (glyucine,aspartic acid,glutamic acid and lysine)and the effects of existences of different concentrations of Cu(Ⅱ) on them.Both the adsorption isotherm of the amino acids on the kaolinite and that when the copper ion Cu(Ⅱ） exists belong to the Langmuir type.The slopes of these adsorption isotherm increase with the increasing concentrations of Cu(Ⅱ） added.It can be explained in terms of formation of the type(Ⅰ） ternary surface complexes in these systems.The regular pattern of the effects of copper ion Cu(Ⅱ) on the adsorption isotherm of amino acids on the kaolinite is identical with that of its effects on the exchange and adsorption percentage E(%)-pH on the kaolinite in the same system.     

海水中微量元素无机离子交换动力学研究——液膜递进模型理论 Ⅰ.天然海水条件下

最近十几年来,海水物理化学中关于海水的化学热力学研究已较广泛地开展,并已有一些重要的研究结果报导。但是,关于海水中化学动力学的研究,至今却基本上仍属空白。然而这正是海洋中许多化学过程(特别像海水化学资源开发、海洋污染和防治等实践性比较强的领域中)要解决的关键问题。本文是我们从事这一方面研究工作的第一篇报导,讨论的内容是海洋中最重要的过程之一——无机离子交换过程。     

A study on the exchange additivity of zinc in solid mixtures in seawater——Ⅱ.Stepwise exchange in δ-MnO2/montmorrillonite mixture

In this study the zinc exchange process and the reason for the non-additive exchange of δ-MnO2/montmorrillonite have been investigated. The results suggest that with pH increasing from 2 to 8, the stepwise exchange of zinc occurs on δ-MnO. and montmorrillonite in their mixture.At low pH zinc ions are bound on δ-MnO2, while at high pH, the exchange on montmorrillonite dominates the surface interaction in the mixture. The study demonstrates that the stepwise exchange and the heterogeneity of the binding sites on δ-MnO2 surface are the reason for the non-additive exchange. It is also shown that when δ-MnO2 amounts to 5 %, zinc exchange on sea sediments is controlled by 8-MnO2.     

一种合成2,2-二甲基-4-戊烯酸的方法

报道一种合成２,２－二甲基－４－戊烯酸的新方法。由异丁醛与烯丙醇缩合得到２,２－二甲基－４－戊烯醛,后者经氧化银选择氧化生成２,２－二甲基－４－戊烯酸。此法氧化产率（９６％）高于分子氧氧化法（６１％）和歧化法（４１％）。反应中析出的金属银能定量回收,循环使用。     

胶州湾海水微表层粘度及其在海-气通量计算中的作用

物质海 -气通量计算新建议中将物质海 -气通量计算公式 F=K(CL- b Cg)中的 CL 用CL ( SML ) 代替。本文着重于对公式中质量迁移系数 K的讨论。在测定了海水微表层、次表层水粘度并同时测定了其它一些化学参量基础上 ,得出如下结论 :海水粘度与盐度、碱度有一定相关性 ;微表层与次表层海水的粘度变化小于 3%。因此 ,海水微表层效应影响 K值 ,与海水微表层效应影响物质浓度相比 ,可以不考虑。     

海水中碳酸根与固体粒子的相互作用

本文研究了海水中碳酸根在固体粒子上的吸附。碳酸根在各种因素颗粒物上的吸附程度上大小顺序为：赤铁矿〉δ－ＭｎＯ２〉水锰矿〉ＳｉＯ２,最大吸附量可达到约２ｍｇＣ／ｇ吸附剂,且最大吸附值均在天然海水ｐＨ（ｐＨ８）左右。在低ＰＨ时,碳酸根对ＮａＣｌ介质中砷酸根的吸附没有影响,在高ｐＨ时,则降低了砷酸根在固体颗粒物上的吸附量,因此碳酸根的存在对其他阴离子的吸附会产生竞争作用。     

砷酸根的液—固界面交换吸附研究——pH和Ca(Ⅱ)的影响

研究ｐＨ和Ｃａ（Ⅱ）对砷酸根在海水与ＮａＣｌ介质中对水合氧化物和粘土矿物上交换吸附的影响：（１）在酸性条件下和海水及ＮａＣｌ介质中，砷酸根在针铁矿上的交换率Ｅ（％）—ｐＨ曲线呈平顶峰型、在δ－ＭｎＯ呈峰型、在粘土上分别呈双峰型和肩峰型。这是砷酸根存在多种形式与固体表面发生离子／配位子交换以及介质中阴离子竞争交换吸附共同作用的结果。（２）在碱性条件下的海水介质中，砷酸根与水合氧化物和粘土矿物的Ｅ（％）—ｐＨ曲线都呈Ｖ型，这是因为生成了具有一定结构的液—固界面三元络合物之故。（３）在ＮａＣｌ介质中，Ｃａ加入起促进作用，再次证明液—固界面三元络合物生成机理与Ｖ型曲线的内在关系     

Determination of copper complexation in surface microlayer of Daya Bay and Jiaozhou Bay

1 INTRODUCTION Bioavailability to the biota and the biogeo-chemistry of trace metals in marine environment areaffected by their chemical speciation in the naturalsystem (Bruland et al., 1991; Van den Berg andDonat, 1992; Wells et al., 1998). Therefore, thesetwo parameters, the ligands concentrations andconditional stability constants, are important todetermine the complexing capacity. Sea surface microlayer (SML), the thin interfa-cial boundary between ocean and atmosphere, playsan imp…     

A new type of isotherm for zinc liquid-solid partitioning on δ−MnO2, γ−MnOOH and manganite in seawater

This article deals with the interaction of zinc with δ−MnO₂, γ−MnOOH and manganite existing in natural water systems. The mechanism of the reaction has been studied in detail. From the fact that the “ratio of ion exchange(%)-pH” graph is an “S shaped” curve, it is possible to deduce that the chemical reaction is of the nature of cation exchange. And since the pH range of ion exchange=4, it is possible to further deduce that the reaction can be explained by the mechanism of monovalence cation exchange. The main result of this article is the discovery of a new type of isotherm which has not been mentioned in previous literature here and abroad. This isotherm cannot be represented by any presently available adsorption isotherm equations in marine chemistry. The characteristics of this new type of isotherm are as follows: the isotherm has two “knees” and three “plateaus”, the heights of these three “plateaus” are in the ratio 1:2:3. In order to explain theoretically our new isotherm, this article suggests the application of the principle of interfacial stepwise ion exchange for liquid-solid distribution of minor elements on suspended particulate matter. The corresponding isotherm equation was derived from this theory. The results obtained in this article will be of theoretical guiding significance in the study of the marine geochemistry of zinc. Projects supported by the Science Fund of the Chinese Academy of Sciences.     

The surface reaction on liquid-solid interface of “amino acid-Cu(II)−MnO2” system in seawater

The results obtained from the Cu(II)%-pH curve of the system in the presence of added amino acid indicated that the added amino acids of higher concentration can inhibit the Cu(II)-σ-MnO₂ ion exchange and that their inhibiting effects decrease in the following sequence when the initial amino acid concentrations are 20.00 ppm: histidine > cystine > glutamic acid > proline > alanine > glycine. The determination of amino acid in solution performed with an amino acid analyser showed that added amino acids react chemically on the surface of the σ-MnO₂ According to thermodynamic equilibria relations in the system, amino acids can be changed to amines because of their decarboxylation on the surface of the σ-MnO₂. Considering (1) the effect-inhibiting factor of amine F_A(β, K_a, pH) representing the complex potential of amine with Cu(II) in solution and (2) the acidic constant of −NH ₃ ⁺ group in the amine molecule representing the ability of cation exchange of the amine with σ-MnO₂, the inhibiting seqence of added amino acid of 20.00 ppm (Eq.(1)) is reasonable. Thus added amino acids do inhibit Cu(II)-σ-MnO₂ ion exchange because (1) the amino acid and/ or amine, which is the decarboxylate of the corresponding amino acid, complex with Cu(II) in solution and compete with σ-MnO₂ for Cu(II); (2) the cation exchange of the amino acid and/or amine reduce the exchange site on the surface of the σ-MnO₂. The results obtained from the isotherms indicated that the theory of interfacial stepwise ion exchange can be extended to the Cu(II) σ-MnO₂ ion exchange system in the presence of added amino acid.