穿透曲线法获取固定床吸附器的传质扩散系数

研究了煤质活性炭对不同浓度苯酚溶液的吸附，应用固定床吸附动力学模型、非线性回归固定床吸附流出曲线数据，获得了酚类在活性炭上的扩散传质系数。结果发现，酚类的表面扩散系数ＤＳ强烈地依赖于入口酚的浓度，随着酚浓度的升高，表面扩散系数增大。采用上述扩散系数理论预测了其他操作条件下的流出曲线，结果表明实验曲线与预测曲线相符甚好，穿透曲线法能可靠地获取液固吸附过程的吸附扩散系数，为吸附工程设计提供有益的帮助     

一种测定吸附塔内液流性能的方法

本文介绍了一种测定吸附塔液流动性能的方法，通过测定吸附塔流出曲线，并对它进行解释，可了解吸附塔有关性能的信息。     

离子交换法制备碳酸钾工艺的改进

在离子交换法制备碳酸钾的工艺中，了交换和再生过程流出液的收集方式，通过将交换过程流出液后段循环至下次交换前段使用，将再生过程流出液后段循环至下次再生前段使用，使产生的氯化铵溶液浓度由４％提高到９％，可回收氯化铵或制成复混肥，减少和消除了环境污染，钾的利用率达８７％，高于原离子交换法工艺。     

电解法回收稀土淋洗液中的铜和EDTA

用电位扫描法研究了EDTA溶液的阳极和阴极行为,确定了电解EDTA溶液时EDTA不分解的条件,提出了用电解法从稀土淋洗液中回收铜和EDTA。中槽试验结果表明,铜的回收率达98％,EDTA94％,EDTA纯度高达98％。     

液固体系固定床吸附器流出曲线预测模型──活性炭吸附水中酚的研究

建立了液固体系的固定床吸附预测模型,并用正交配置法获得了模型方程的数值解,实验测定了苯酚在活性炭上的静态和动态吸附数据,采用Marquadt法优化固定床吸附流出曲线数据,得到了不同浓度条件下的表面扩散系数及其变化规律,并据此预测了其他操作条件下的穿透曲线,预测曲线与实验结果相符甚好．     

核电厂放射性废液贮槽间滞留功能改进

根据相关法规的要求，中等放射性废液贮槽间宜设置不锈钢敷面。分析了某型核电厂液体放射性废物系统流出液暂存槽间增设不锈钢覆面的必要性，对流出液暂存槽间的现状进行了详细的描述，指出了在严重事故工况下贮槽破裂后房间无法滞留放射性废液的问题。针对上述问题，给出了两种解决方案，从可靠性、成熟性及操作性的角度对比分析并确定最终方案，既保证了严重事故后流出液暂存槽间的滞留废液能力，又满足了正常运行工况下房间收集地面疏水的要求，最后对方案进行了总结。     

烟气中一氧化氮的液相吸收与综合利用

采用两步法来脱除烟气中的一氧化氮,首先以FeⅡEDTA溶液来配位固定烟气中的一氧化氮,然后用双氧水把配位固定的一氧化氮氧化为硝酸根。为了使吸收液再生,调节溶液的pH为4.0,加入铁粉还原溶液中生成的FeⅢ,使其转化为FeⅡEDTA,可继续吸收烟气中一氧化氮。实验时考察了FeⅡEDTA吸收液的pH、浓度、温度和双氧水用量等对FeⅡEDTA吸收一氧化氮和进一步氧化为硝酸根的效率的影响。研究表明：用浓度为0.13 mol/L的FeⅡEDTA吸收液吸收一氧化氮达到饱和后,取适量吸收溶液,向其中加入双氧水氧化,氧化后可生成硝酸根浓度为0.109 mol/L的溶液,一氧化氮的吸收氧化效率可达83.8%。吸收液循环使用5次后,用调节pH等方式可把溶液中的EDTA、铁盐和硝酸盐等回收以达到综合利用的目的。吸收液经过5次循环吸收后,EDTA的回收率为93.1%。     

酸性镀铜液中硫酸铜的光度测定

用EDTA作显色剂，通过光度法测定酸性镀铜液中硫酸铜的含量，研究了测量波长，缓冲液的用量和EDTA用量对测量结果的影响，讨论了干扰因素的影响及其消除方法，硫酸铜含量在0－4mg/mL范围内遵守比尔定律，本方法简便，快捷，准确度和精密度高，适用于大批量样品的分析。     

络合沉淀法制备高纯纳米二氧化钛

以硫酸氧钛和乙二胺四乙酸（EDTA）为原料，采用络合沉淀法在撞击流一旋转填料床反应器内制备了高纯纳米二氧化钛粉体。用TEM和XRD对粉体的形貌和晶相进行了表征，并分析了EDTA对产品纯度和产率的影响。结果表明：引入EDTA可以有效控制粉体粒径，有利于固液分离，实现产物高纯化。所制备的二氧化钛粉体分散性较好，平均粒径为50～60nm，纯度为99．87％；控制不同的焙烧温度可以得到不同晶相的氧化钛。     

百菌清催化剂(以活性炭为载体)中铝和锌的同时测定—离子交换树脂分离法

(一)前言百菌清催化剂中铝锌的测定,曾采用在抽提液中以过量碱沉淀Fe,而铝锌则溶于碱液中,在pH4～5时,用EDTA络合铝,再以NH_4F从EDTA铝中络合铝,用ZnSO_4标准液回滴析出的EDTA。锌的测定,则在抽提液中加入过量的碱,使铝锌都溶于     

化学镀铜废液的综合利用和处理

探讨了利用原化学镀铜废液中的甲醛将铜还原，后酸化回收EDTA的新工艺。实验证明，该工艺铜的去除率可达99％，甲醛去除率为68．9％，同时EDTA的回收率为96．6％。用这种方法回收的EDTA纯度大于97％，可直接回用于化学镀铜工业。     

Effect of EDTA on total dissolved copper concentration in textile effluents

The expected fate of copper in textile effluents has been examined in the context of an activated sludge waste treatment scenario, using experimental rate constants and results from previous sorption studies. The effect of EDTA on total dissolved copper concentrations, in effluent streams during waste treatment, is discussed in terms of competitive sorption and sequestration kinetics. For this purpose, rate constants for the reaction of EDTA with five reactive dyes were estimated spectrophotometrically. The results of these experiments show that the use of excess sequestrant can dramatically increase total dissolved copper concentrations in the effluent stream.     

Simultaneous recovery of heavy metals and degradation of organic species – copper and ethylenediaminetetra‐acetic acid (EDTA)

In mixed industrial effluent the presence of metal ions can retard the destruction of organic contaminants and the efficiency of recovery of metal is reduced by the presence of the organic species. Results are presented for a copper–ethylenediaminetetra‐acetic acid (EDTA) system in which both effects occur. An electrochemical cell alone can be used to recover copper in pH range 1.5–4.5 but is not capable of achieving complete mineralisation of EDTA by anodic oxidation. A photolytic cell alone can achieve the destruction of EDTA at pH 3.5 but leaves copper in solution. A combined photolytic–electrochemical system using an activated carbon concentrator cathode achieves the rapid simultaneous destruction of EDTA and recovery of copper. © 2000 Society of Chemical Industry     

Solution equilibrium characteristics of electroless copper deposition on thermally-activated palladium-catalysed polyimide substrates

Solution equilibrium characteristics of two electroless copper baths containing EDTA and tartrate as the complexing agents were studied as functions of pH. Equilibrium diagrams were constructed for both Cu-tartrate and Cu-EDTA systems. It was determined that copper is chiefly complexed as Cu2L2 in acidic conditions and as Cu(OH)2L2–4 in alkaline conditions in the tartrate bath, and as CuA–2 in the EDTA bath, where L and A are the complexing tartrate and EDTA ligands, respectively. Electroless copper deposition rates were studied from a tartrate bath on thermally activated palladium-catalysed polyimide substrates as functions of copper and formaldehyde concentrations, and pH.     

Removal of Ethylenediaminetetraacetic acid (EDTA) from Pulp Mill Effluents by Ozonation

Ozone application was investigated for its effectiveness in the removal of ethylenediaminetetraacetic acid (EDTA) from bleaching effluent. The objectives were to compare the efficiency of ozone reaction on Na-EDTA solution with pure Fe³⁺-EDTA complex and EDTA complexes in bleaching effluent, and to test if changing pH and addition of hydrogen peroxide (H₂O₂) increases the removal of EDTA. Small ozone doses destroyed high proportions of Na-EDTA. This effect was diminished when EDTA formed complexes with other metal ions. It was shown that EDTA present in bleaching effluent was more easily oxidizable than in pure Fe³⁺-EDTA solution. Variation of initial pH value had no significant influence on the removal of Na-EDTA. Addition of hydrogen peroxide did not increase degradation of EDTA in bleaching effluent.     

以次磷酸钠为还原剂的化学镀铜

研究了以次磷酸钠为还原剂的化学镀铜过程。确立了以硫酸铜为主盐,次磷酸钠为还原剂,乙二胺四乙酸二钠和柠檬酸钠为混合配位剂的碱性还原镀铜体系。在铸铁基体上实现了铜的连续自催化沉积,获得了较光亮、红黄色的铜镀层。     

Study on EDTA‐chelated copper adsorption by granular activated carbon

Equilibrium and kinetic experiments on uptake of single‐species copper, EDTA, and EDTA‐chelated copper by an H‐type granular activated carbon under various factors, such as pH, ionic strength and EDTA concentration were carried out in this study. Adsorption of copper ions was increased with an increase in solution pH when the solution contained single‐species or EDTA‐chelated copper ions. The solution pH increased significantly from its lower initial value, which resulted from the adsorption of hydrogen ions by the carbon. The efficiency for the single‐species metal ion removal was increased from 5 to 95% when the solution pH was increased from 2 to 7.5. EDTA‐chelated metal ion removal, however, was increased from 7 to 97% as the pH was increased from 1.5 to 7.5. EDTA adsorption percentages increased when the solution pH was increased and the initial concentration was decreased. Slightly higher EDTA‐chelated copper removal was observed when the ionic strength was higher and the ratio of EDTA to copper concentrations was 1:1. Kinetic experiments demonstrated that the copper adsorption occurred rapidly in the first hour. No further change in the removal was observed after 3 and 6 h for single‐species or EDTA‐chelated, respectively. The EDTA‐chelated copper adsorption kinetics was enhanced with an increase in EDTA concentration and a decrease in ionic strength. © 2000 Society of Chemical Industry     

The Adsorption and Desorption Characteristics of EDTA-Chelated Copper Ion by Activated Carbon

Abstract

This paper addresses the effect of EDTA, a strong agent, on the removal of copper ion from solutions using activated carbon adsorption. Experimental studies indicate the presence of EDTA significantly altered the adsorption behavior of copper on the activated carbon due to the formation of copper chelate species in the solution. The adsorption isotherms and kinetics were found to be strong functions of solution pH and the ratio of copper ion and EDTA concentrations. Adsorption of EDTA-Cu chelates was found to be more favorable than those of free copper ion and unbound EDTA species in the solution. Experimental results indicated that the desorption of chelated copper ion from activated carbon by NaOH and HClO⁴ solutions was influenced by the initial adsorption conditions. A significantly higher quantity of copper ion was recovered with HClO⁴ than with NaOH. Combining the adsorption and desorption data of copper and EDTA, and an understanding of the species distribution of copper in the presence of EDTA, the behavior of the adsorption of EDTA-chelated copper on the activated carbon was described. The predominant adsorbed copper species was the chelated form, CuEDTA^2-, which can be adsorbed on activated carbon surfaces with either the Cu end or the EDTA end bonding directly to the surface.     

钢铁基体上无氰碱性电镀铜用配位剂的研究

分别以乙二醇、乙二胺四乙酸(EDTA)、氨水、缩二脲、柠檬酸盐及膦酸盐为配位剂进行无氰碱性镀铜试验。对不同镀液体系的稳定性、电导率及所得镀层的外观、结合力等进行了测试。结果表明,乙二醇、EDTA、柠檬酸盐及膦酸盐都可以作为碱性镀铜的配位剂,而氨水和缩二脲体系由于存在明显的置换反应,因此不适用于无氰镀铜体系。复合膦酸盐镀铜体系的综合性能最好,有望替代传统的氰化物镀铜体系。     

Interference of EDTA in the treatment of metal plating wastewater by biosorption

BACKGROUND: The applicability of biosorption for the treatment of metal plating wastewater is adversely affected by the presence of complexing agents. To investigate this limitation on the removal of copper(II) onto peat, batch and column experiments were carried out using EDTA as the model complexing agent. The influence of pH and copper(II):EDTA mass ratios were evaluated for copper(II) concentrations between 5 and 100 mg Cu(II) dm^?3. RESULTS: EDTA negatively affected the copper(II) uptake of peat for pH > 5. Batch and column experiments showed that copper(II)‐EDTA complexes were not sorbed by peat. The leaks of copper(II) detected from the beginning of the column operation matched the copper(II)‐EDTA concentration in the feed solutions. To overcome the interference of EDTA, a novel approach based on the combination of peat + activated carbon was proposed. Nearly complete removal of copper(II) was maintained over 70 h in the treatment of a solution containing 20 mg Cu(II) dm^?3 with 11% of copper(II)‐EDTA complexes. CONCLUSION: A new mass transport model coupling copper(II) speciation in the feed and mass transfer rate‐controlled process simulated the copper(II) breakthrough curves in the presence of EDTA and could be used to successfully predict the breakthrough point. This work demonstrated that biosorption can also be applied for the treatment of wastewater containing complexing agents with the proper combination of sorbent materials. © 2012 Society of Chemical Industry