SOLID-LIQUID INTERFACE PROCESS OF HEAVY METALS IN THE CHANGJIANG ESTUARYKINETICS OF ADSORPTION OF Pb, Cu AND Cd ON HFO

The adsorption kinetics of Pb, Cu and Cd on hydrous ferrk oxide (HFO) has been approached in tthe simulated environmental conditions of the Changjiang Estuary. The forward adsorption rate constants of different systems under different temperatures have been determined, and the activation energies of the adsorption for Pb and Cu evaluated (Pb=7 kcal/mol, Cu= 11 kcal/mol). The results show that Pb and Cu are strongly adsorbed by HFO; the order of their adsorption rate is found to be Pb≥Cu≥Cd, which follows thte order of their theonody-namic equilibrium constants. It has been demonstrated that the surface exchange-adsorption is the determining step of the solid-liquid interface process. The field investigation results are theoretically explained by the kinetic mechanism.     

长江口重金属固液界面过程Ⅲ.水合氧化铁吸附Pb、Cu、Cd的动力学

本文模拟长江口某些环境条件,研究了水含氧化铁吸附Pb、Cu、Cd的动力学,测定了不同体系、不同温度下的正向速率常数,估算了Pb、Cu的吸附活化能分别约为7和11千卡/克分子.结果表明:水合氧化铁对Pb、Cu的吸附能力较强,对Pb、Cu、Cd三元素的吸附速率次序为Pb>Cu>Cd,与热力学平衡常数的次序相一致.论证了表面交换吸附反应是此固液界面过程的控制步骤的动力学机理,从而可对长江口现场调查结果予以理论上的解释.此外,本文探讨了界面吸附的正向速率常数和活化能的估算方法.     

厦门西港筼筜湖排污口区底质环境要素的分布

本文报道1995年8月厦门西港筼筜湖排污口区底质调查监测结果。Cu、Pb、Zn、Cd、Hg、S2、oil、org．等环境要素平均含量分别为：34．6、74．5、140.3、1．96、0．096、315.6、104．5（×10－6m／m）、1．71×10-2（m／m）。超标率分别为：50．0％、100.0％、100.0％、100.0％、0.0％、12.5％、0.0％、0.0％。Cu、Hg、S2-、oil、org．、Eh等环境要素极值出现在排污口（4号站），以其为中心呈扇形状向海方向逐渐降低，这些污染物来自筼筜湖，对局部海域造成污染。与1982年比较有增加趋势。     

THE BEHAVIOR AND SEDIMENTATION MECHANISM OF Pb, Cu AND Cd IN SEDWAENTARY PHASE OF THE CHANGJIANG ESTUARY

The authors have determined the distributions of Ph, Cu and Cd ia surface sediment, acid-soluble fraction and interstitial water of the Changjiang Estuary and analysed the relationship between them and some environmental parameters, finding that there exists a quasi-equilibrium between the interstitial water and the sediment. The distribution of Pb or Cu in both phases it controlled mainly by the adsorptioa-desorption and deposition-solution processes of HFO" and org." in the sediments, whereas Cd is mainly controlled by the depoahisn-Jolution process of CdS. The sedimentation mechanism of Ph, Cu and Cd in the Changjlang Estuary is preliminarily proposed.     

SOLID-LIQUID INTERFACE PROCESS OF HEAVY METAL IN THE CHANGJIANG ESTUARYADSORPTION THERMODYNAMIC MODEL OF Pb, Cu AND Cd BY HYDROUS FERRIC OXIDE

The adsorption of Pb, Cu and Cd on synthetic hydrous ferric oxide (HFO) has been performed under simulated environmental conditions of the Changjiang Estuary. An improved M2 - H exchange-adsorption model is proposed to explain the adsorption processes. The adsorption of these elements falls in the order: Pb ≥ Cu > Cd and has a good coincidence with the field results obtaimed from the Estuary. It has been concluded that the adsorption processes of Pb and Cu on HFO are mainly chemical actions, whereas static-electrical action dominates in the case of Cd.     

九龙江口厦门港沉积物中镉、铜、铅的分布和行为

一、前言河口区是江河所携带的泥砂、悬浮物和各种化学物质的主要沉积场所。河流悬浮物是重金属元素很好的清除剂。在河口水质条件急剧变化和复杂的化学、生物等过程中,它们能从水体中吸附大部分的重金属元素一起进入沉积物。Hely指出:Back河口海水中有些痕量金属的浓度要比排入该河废水中低10—100倍,这种减少既有海水的稀释作用,也有流出物中所含有颗粒的沉积作用,而更重要的是悬浮物的吸附和聚沉作用。因此测定河口沉积物中痕量重金属含量(总含量和各种可能迁移相),通常能预示该地区的污染情况。如果再指出它们与沉积物的某些重要组份及所处环境条件,就有可能进一步了解河流物质进入海洋的过程和机制。     

长江口重金属元素固-液界面的过程——Ⅱ.水合氧化铁对Pb、Cu和Cd吸附的热力学模式

模拟长江口某些环境条件,用制备的水合氧化铁对Pb、Cu和Cd进行吸附实验,不同温度下的数据均符合Langmuir等温式.测定了各元素的饱和吸附量、吸附热、平衡常数及其他热力学参数.溶液pH对吸附有明显的影响,各元素均在一定的pH区间产生吸附突跃,吸附过程可用改进的M2+-H+表面化学交换模式说明.初步确定:水含氧化铁对Pb、Cu的吸附以化学作用为主;Cd的吸附则以静电作用为主.模拟结果与现场调查结果基本一致,进一步对吸附过程的热力学性质给予定量的描述.     

惠安南埔湾海水养殖区一次油污染的监测

对福建炼油厂１９９３年２月１２日溢油事故的监测结果表明，惠安县南埔湾的天竺，张俱，仑头一带养殖区域已受到溢油的严重污染。湾内养殖的主要经济贝类活体的油含量大大高于长江口以南沿岸海域同种类的生物样，其中养殖区域的牡蛎，缢蛏，花蛤活体内油含量分为（２３８－２２７０）×１０×－×６（ｍ／ｍ），２８４０×１０＾－＾６（ｍ／ｍ），（２７６－２９４）×１０＾－＾６（ｍ／ｍ），平均死亡率高达７０％以上，残活生物     

长江口重金属元素的固液界面过程——Ⅰ.沉积相中Pb、Cu和Cd的行为和沉积机理

本文阐述了长江口表层沉积物及其酸可溶相和间隙水中Pb、Cu和Cd的分布,分析了它们与环境参数的关系,发现它们的多数与沉积物的粒度、有机质、氧化铁和粘土矿物的含量之间有较好的相关性,与Eh、pH也有一定的关系.间隙水和沉积物之间存在着准平衡关系.Pb、Cu在两相间的分配主要受氧化铁和有机质的吸附-解吸和沉淀-溶解过程所控制,Cd的分配主要受CdS的沉淀-溶解过程所控制.     

长江口底质腐殖酸铜铅络合物的表观稳定常数

采用差示脉冲阳极溶出极谱法测定了长江口底质腐殖酸每个分子中可键合金属位置的平均数,计算其平均分子量约为800,并估算出长江口底质腐殖酸-铜、铅络合物的表现稳定常数高达10~(11)-10~(12)数量级。