离子交换纤维对含铬废水的资源化治理

发布时间：2018-01-05 05:33

本文关键词：离子交换纤维对含铬废水的资源化治理　出处：《郑州大学》2015年硕士论文　论文类型：学位论文

【摘要】：离子交换技术在对含重金属工业废水进行深度净化的同时,还能实现各种重金属的资源化回收。然而离子交换法在治理含铬废水的实际应用中仍存在下述不足:(1)弱碱型阴离子交换剂在使用过程中需转为Cl型,导致回收液中氯离子含量增加,返厂电镀时对铬镀层质量有较大影响。(2)弱碱型阴离子交换剂可吸附一定量的Cr3+、Fe3+等阳离子(吸附量约为1.5mmol/g),再生时易形成不溶物或与阴离子吸附材料形成螯合物,从而导致其交换容量下降。实验室前期研究中也发现腈纶(PAN)基多胺纤维转为Cl型,会导致铬酸回收液中的Cl-浓度偏高(CCl-"g2 g/L);处理后的废水呈弱酸性(p H≈3),无法直接达标排放。基于上述原因,本文采用PAN基多胺纤维处理工业含铬废水,并对多柱串联工艺进行优化。系统研究了六价铬的净化与回收,初步探讨了纤维的“污染”机理,为Cr(VI)的资源化治理提供一个可供选择的新方法。主要研究内容为:(1)通过将PAN基多胺纤维部分转型的方法优化多柱串联工艺,以及利用纤维对Cr(VI)、SO42-、Cl-吸附选择性的差异,实现铬酸回收液中Cr(VI)高度富集和SO42-、Cl-离子选择性滤除。结果表明,该工艺不仅可以明显减少盐酸的用量(用量为原来的1/9),有效降低回收液中Cl-含量(约0.04 g/L),还使得穿透前(CCr(VI)"f0.1 mg/L)出水p H值接近中性,可直接作为电镀用水循环使用。(2)通过高浓度Na OH洗脱液重复套用方法,有效提高了Na OH利用率(节约了52%)及回收液中六价铬浓度(约48g/L),为其在电镀工序中的循环回用提供条件。(3)流速对吸附及再生影响较大。吸附流速为2m L/(g·min)时,纤维饱和吸附量较大;再生速度为0.5m L/(g·min)~2m L/(g·min)之间,纤维再生较为完全。(4)多柱串联优化工艺稳定性较好。经过多次吸附再生循环,PAN基多胺纤维对Cr(VI)的穿透吸附量基本保持不变,该六价铬资源化治理工艺具有良好的工业化应用前景。(5)以盐酸溶液为纤维复苏剂,系统考察了HCl溶液用量、浓度以及复苏温度、时间和流速等因素对纤维复苏率的影响。结果表明:HCl溶液浓度为3mol/L,复苏效果最好(复苏率达95%以上)。
[Abstract]:Ion exchange technology for deep purification of industrial wastewater containing heavy metals, but also can realize the resource recycling of various heavy metals. However, the application of ion exchange method in treatment of wastewater containing chromium still exist in the following problems: (1) weakly basic anion exchange agent used in Cheng Zhongxu to Cl, resulting in the increase of chloride ion in liquid in the recovery, return to factory plating has a great influence on the quality of chromium coating. (2) weakly basic anion exchange agent can absorb a certain amount of Cr3+, Fe3+ and other cations (adsorption capacity is about 1.5mmol/g), the regeneration is easy to form insoluble or anion adsorption material to form chelate, which leads to the exchange capacity decreased. The previous study also found in Polyacrylonitrile (PAN) fiber polyamine to Cl type, it can cause high Cl- concentration of chromate in the recovery liquid (CCl- G2 g/L); the treated wastewater is acidic (P H = 3), no direct standard Discharge. Based on the above reasons, the treatment of industrial wastewater containing chromium PAN polyamine fibre, which is optimized for multi column series process. Six chromium purification and recovery system, discusses the fiber "pollution" mechanism, Cr (VI) provides a new method for the selection of resources governance. The main contents are as follows: (1) the PAN transformation part polyamine fiber method optimization of multi column series technique, and the use of Cr fiber (VI), SO42-, the difference of Cl- adsorption selectivity, achieve chromate in the recovery liquid Cr (VI) are highly enriched and SO42-. The results show that Cl- ion selective filter this process, not only can significantly reduce the amount of hydrochloric acid (the amount of 1/9 of the original), effectively reduce the content of Cl- in liquid recovery (about 0.04 g/L), also makes the penetration before (CCr (VI) F0.1 mg/L) P water H value close to neutral, can be directly used as electroplating water recycling by (2). High concentration Na OH eluent repeatedly apply the method, effectively improve the utilization rate of Na OH (save 52%) six chromium concentration and recovery (about 48g/L), to provide conditions to its circulation in electroplating process. (3) effect of flow rate on the adsorption and regeneration greatly. The adsorption rate was 2m L/ (G - min), fiber saturated adsorption capacity is bigger; regeneration rate of 0.5m L/ (g min) ~2m L/ (G - min), fiber regeneration more completely. (4) multi column series optimization process is stable. After several adsorption regeneration cycles, PAN polyamine fiber for Cr (VI). Adsorption capacity remained unchanged, the six chromium resource management technology has good prospects in industrial applications. (5) in hydrochloric acid solution for fiber recovery agent, the effect of the HCl solution concentration and dosage, recovery time and temperature, flow rate and other factors impact on the recovery rate of the fiber. The results showed that the concentration of HCl solution 3mol/L complex The Soviet Union had the best effect (the recovery rate was over 95%).

【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

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