MODELING OF COPPER ION REMOVAL FROM AQUEOUS SOLUTIONS USING MODIFIED SILICA BEADS

Silica beads, containing 2-hydroxy-5-nonylacetophenoneoximc (LIX84) were prepared in order to examine the removal of copper ions from aqueous waste solutions. The process for copper ion removal using the modified silica beads was mathematically modeled using both a non-equilibrium model and an equilibrium model. The external mass transfer coefficient and effective diffusivity inside the bead pore were estimated by matching the experimental data and predicted values from the model, and the results were compared. The results of the two models were similar and in good agreement because of the relatively faster reaction rate than mass transfer rate. Sensitivity analyses showed that the external mass transfer has more influence on the copper ion removal system because of hydrophobic effects.     

MODELING OF COPPER ION REMOVAL FROM AQUEOUS SOLUTIONS USING MODIFIED SILICA BEADS

Silica beads, containing 2-hydroxy-5-nonylacetophenoneoximc (LIX84) were prepared in order to examine the removal of copper ions from aqueous waste solutions. The process for copper ion removal using the modified silica beads was mathematically modeled using both a non-equilibrium model and an equilibrium model. The external mass transfer coefficient and effective diffusivity inside the bead pore were estimated by matching the experimental data and predicted values from the model, and the results were compared. The results of the two models were similar and in good agreement because of the relatively faster reaction rate than mass transfer rate. Sensitivity analyses showed that the external mass transfer has more influence on the copper ion removal system because of hydrophobic effects.     

活性炭-纳滤膜工艺去除饮用水中总有机碳和可同化有机碳

本分别以地表水和地下水为水源的水厂出水为研究对象,探讨了活性炭－纳滤膜工艺对饮用水中总有机碳和可同化有机碳的去除效果及机理。结果表明,活性炭的吸附作用受其本身性质和有机物特性影响较大,去除能力有限;纳滤则可将水中总有机碳和可同化有机碳大都去除,确保饮用水的安全性和生物稳定性。两的组合是获得优质饮用水的有效处理工艺。     

活化稻壳纯化废液及再利用去除石英砂中的铁杂质

采用活化稻壳作为吸附剂纯化废液,再利用其去除石英砂中铁杂质。吸附剂的制备是在110℃下,质量分数1%的KOH溶液活化稻壳1 h,然后于600℃热处理2 h。研究了KOH的浓度、吸附剂的量、吸附时间、吸附液初始浓度和温度参数对去除废液中铁和铝的影响。结果表明,在最优试验条件下,铁和铝的去除率分别为97.2%和94.2%。研究发现纯化的废液对石英砂中铁的去除率远高于未纯化废液;在额外添加3.6%的磷酸时,纯化废液对铁的去除率达到77.1%,这项技术不仅可以节省大量的水(966 kg/m3)和磷酸(57.8 kg/m3)还可以避免环境污染。     

老龄垃圾渗滤液高氨氮的电化学氧化及其能耗分析

针对垃圾渗滤液高氨氮、难生物降解的特点,采用电化学氧化法对含高浓度氨氮的垃圾渗滤液进行预处理,考察了不同电极材料、电流密度、Cl-质量浓度、pH、极水比等因素对渗滤液中高NH3-N去除的影响,分析了电化学氧化法处理垃圾渗滤液的能耗和电流效率。结果表明,在电流密度30 mA.cm-2、Cl-质量浓度5 000 mg.L-1、pH为8、极水比17.8 m2.m-3的条件下,以Ti/RuO2-IrO2-TiO2电极为阳极电解6 h后,NH3-N的去除率、电流效率和比能耗分别为99.9%、35%和91.9 kWh.kg-1。     

间歇曝气生物滤池对焚烧垃圾渗滤液脱氮的挂膜启动和运行工况研究

为了克服传统曝气生物滤池脱除焚烧垃圾渗滤液总氮效果差的缺点,开发了间歇式曝气生物滤池。通过曝气与停曝的交替循环,使整个反应器轮流出现好氧、缺氧、厌氧的环境从而提高脱氮效率。对于反应器的启动,采用闷曝、小流量逐渐增加负荷连续进水和投加碳源菌种间歇曝气3阶段挂膜法,总挂膜时间为17 d。另一方面,不同的进出水方式对反应器的脱氮效率有较大影响,采用曝气阶段停止进水,停曝阶段加倍进水的运行方式可以使得间歇曝气生物滤池取得最好的脱氮效果,氨氮去除率为75%,总氮去除率为67%。     

成型方法对用辊棒废料制备的瓷球性能的影响

分别采用等静压成型与手搓成型工艺制造氧化铝瓷球；研究表明不同的成型方法不仅对瓷球的烧成及物理性能有影响，且对其磨损规律有着很大的影响；等静压成型瓷球的烧结温度较手搓成型瓷球要低，硬度及密度比手搓成型瓷球要高；手搓成型瓷球的磨损率随时间增加而增加，等静压成型瓷球的磨损率随时间增加而相应减小。     

REMOVAL OF HEAVY METAL IONS FROM INDUSTRIAL WASTE WATERS

The reaction of cyclohexene over tellurium loaded NaX zeolite has been studied kinetically and new reaction pathways have been developed to explain observed phenomena. The reaction of cyclohexene is believed to involve extensive disproportionation of cyclohexene molecules and hydrogen transfer between cyclohexene and intermediate cyclohexadiene molecules. The kinetics of the system is discussed in terms of adsorption based rate models.     

氧化铝对水体中重金属离子吸附去除研究

以木材防腐剂CCA中的重金属铬、砷和铜为研究对象,评价了氧化铝对3种重金属的同时吸附去除效果,并对3种重金属在氧化铝上相互作用机理进行了探讨.结果表明,铬对氧化铝去除砷和铜均无显著影响;砷显著抑制氧化铝对铬的去除,但促进铜的去除;铜促进氧化铝对铬和砷的去除;铬主要通过外层作用(静电吸附,离子交换等方式)吸附在氧化铝的表面上;而砷主要通过内层吸附(专性吸附)在氧化铝的表面上,因而引起氧化铝的等电点朝较低的pH移动;铜主要通过专性吸附和沉淀作用得以去除.总体上,在中性环境下,氧化铝对3种重金属可同时具有较好的去除效果.     

含汞金矿堆浸富液沉淀-絮凝法选择性除汞技术

含汞金矿在堆浸喷淋提金过程中汞与金一起被氰化浸出。为消除后续解吸、电解、,台炼以及活性炭再生过程中的汞污染问题,拟对堆浸富液进行除汞预处理,即采用沉淀．絮凝法选择性去除富液中的汞杂质。考察絮凝剂种类（即FeSO4、明矾、AlCl3和PAM）、Na2s加入量、沉淀pH值调节及其氢氧化物沉淀预分离对除汞效果和金损失率的影响。结果表明：（1）堆浸富液中除了Hg^2＋外,还存在较多会消耗Na2S的离子,如Ar^＋、Fe^2＋、Cu^2＋、Zn^2＋ 、Mn^2＋ 矿和Pb^2＋等,因而Na2S实际加入量显著增大,较佳Na2S／Hg质量比为12左右。（2）采用FeSO4＋PAM作为絮凝剂,能显著加快硫化物沉淀物的沉降,极有利于其工业化应用。（3）适当提高堆浸富液的pH值（11左右）,并将产生的氢氧化物沉淀倾滤分离。可以适当降低Na2S加入量,而不影响汞的去除率。     

A/O~2-Fenton-BAF工艺处理焚烧垃圾渗滤液试验研究

以某垃圾焚烧厂渗滤液为对象,采用厌氧-2级好氧(A/O2)-Fenton-曝气生物滤池(BAF)组合工艺进行中试。结果表明,在COD负荷为220 g.m-.3d-1下,COD和氨氮去除率可达到85.3%和92.9%;Fenton反应适宜投加量为H2O2:COD=2,n(Fe2+):n(H2O2)=1,BAF参考设计处理COD负荷为188.6 g.m-3.d-1,处理后出水COD低于80 mg.L-1,氨氮的质量浓度低于2 mg.L-1。通过提升负荷考察其对生化处理的影响,确定高负荷下采用2级好氧对去除氨氮的必要性,为工艺改造应用于工程中提供参考。     

纳滤膜技术在垃圾渗沥液处理中的应用

垃圾渗沥液水质复杂多变,污染物浓度高,直接排放危害巨大。结合柳州垃圾填埋场工程实例,采用生化、物化、纳滤等综合工艺的处理方式,重点介绍纳滤膜分离技术在垃圾渗沥液处理中的应用情况,为我国今后垃圾渗沥液处理提供参考。     

不同传质方式对电化学氧化垃圾渗滤液的效率分析

研究了不同传质方式对高氨氮垃圾渗滤液的电化学氧化效率,重点考察了高压水喷射电极板、曝气、搅拌及不搅拌4种传质方式对电解过程中的电解速率、电流效率、能耗的影响。结果表明,传质方式不同对电解过程中氨氮及COD的去除影响明显。其中,高压水喷射电极板方式具有高的电解速率、电流效率以及低的能耗,在电解6 h的过程中电解速率为7.41 mg/(L.min),电流效率为48%,电解氨氮能耗为0.11 kWh/g。不同传质方式具有不同的传质系数,提高传质系数能够提高传质速率,从而提高系统的整体效率。     

粒子电极对垃圾渗滤液的电催化降解

用自制负载型CuO-CeO2/γ-Al2O3粒子和活性炭颗粒作混合填料,利用三维电化学体系处理垃圾渗滤液.考察了槽电压、pH、气体流量和极间距等因素对渗滤液降解的影响.结果表明,该体系对渗滤液具有较好的催化降解效果.当槽电压为15.0V、pH为中性、气体流量为0.08m3/h、极间距为3.0cm时,垃圾渗滤液COD和NH3-N的去除率分别达到92.9%和94.7%.采用紫外-可见光谱对反应中间产物进行定性分析,探讨体系电催化氧化反应机理.     

稀醋酸催化精馏过程的反应动力学

研究了常压下温度308-328 K范围内用阳离子交换树脂作催化剂的稀醋酸合成醋酸甲酯本征反应动力学,得到基于Langmuir-Hinshelwood吸附理论用活度表示的通用动力学方程,在此基础上建立了数学模型并通过模拟计算证明了催化精馏过程是回收水溶液中醋酸的有效方案,为工业设计放大提供了理论依据.     

AMINE REMOVAL FROM WASTE WATER BY LIGAND EXCHANGE

Ligand exchange is a process in which a substance is removed from solution by complexing with a metal ion held on an ion exchange resin. This paper presents basic data on separation of ethanolamine and butyl amine from dilute aqueous solution by complexing with copper(II) ion held on a carboxylic acid type resin. Experimental equilibrium curves and ligand exchange breakthrough curves are presented for the two amines. The equilibrium curves are satisfactorily represented by an empirical Langmuir isotherm. The breakthrough curves are successfully modelled by the Thomas mathematical formulation using a mass transfer controlled rate mechanism. The ligand exchange process may be useful commercially for removal of amines from aqueous waste streams.     

AMINE REMOVAL FROM WASTE WATER BY LIGAND EXCHANGE

Ligand exchange is a process in which a substance is removed from solution by complexing with a metal ion held on an ion exchange resin. This paper presents basic data on separation of ethanolamine and butyl amine from dilute aqueous solution by complexing with copper(II) ion held on a carboxylic acid type resin. Experimental equilibrium curves and ligand exchange breakthrough curves are presented for the two amines. The equilibrium curves are satisfactorily represented by an empirical Langmuir isotherm. The breakthrough curves are successfully modelled by the Thomas mathematical formulation using a mass transfer controlled rate mechanism. The ligand exchange process may be useful commercially for removal of amines from aqueous waste streams.     

臭氧氧化法处理密闭式清洁站垃圾沥滤液试验研究

以密闭式清洁站产生的垃圾渗滤液为对象,控制反应体系条件为:酸性(pH<4),室温,研究臭氧氧化反应时间、曝气方式、曝气流量与有机物去除率之间的关系。研究结果表明,臭氧氧化试验反应前2 h,反应速率较快,对COD、NH3-N、BOD5的去除率分别达到52.8%、46.8%、55.8%,此后臭氧氧化速率降低,去除率变化不大;当曝气流量提升到2 L/min以后,有机物的去除效率变化不明显;一定的曝气量下,曝气方式对有机物的去除几乎无影响。经过臭氧氧化反应后,渗滤液浓度依旧较高,因此臭氧氧化须与其它处理技术相结合,才能满足出水水质的要求。     

长沙市固体废弃物处理场渗沥液处理工程

长沙市固体废弃物处理场渗沥液处理工程是目前国内达到垃圾填埋场污染物排放限制(GB 16889-2008)要求的大型渗沥液处理厂,于2010年6月建成,最大处理规模达到1 500 t/d,采用(A/O)2-MBR+RO/NF处理工艺设计。经运行验证,处理系统稳定高效,出水水质良好达标。文中对工程概况、污水特点、工艺流程、单元设计及运行效果进行了说明,并对本项目设计经验进行了总结。     

废弃茶叶渣净化水体中重金属的研究进展

在对茶叶的结构和基本性质进行简单介绍的基础上,综述了茶叶渣吸附重金属离子的研究进展,包括吸附性能的研究和吸附机理的研究。并进一步介绍了茶叶渣吸附重金属离子的主要影响因素,包括溶液pH、固液接触时间、金属离子的初始浓度、吸附体系的温度等影响因素。最后对茶叶渣净化重金属污染水体的实际应用做了展望。