论文总字数：14997字

摘 要

六价铬是一种毒性较大的重金属，因其高溶解性对于生物及环境都有很大的危害。本文将铜氧化物负载到大孔强碱性系阴离子交换树脂D201上制备了新型水体除铬吸附剂CuO@D201。通过控制pH、竞争离子、温度、时间等操作条件研究所制备吸附剂对水中六价铬离子的吸附效果。结果表明：在相同的温度条件下，CuO@D201较载体D201的吸附量明显增加，且CuO@D201的吸附效果随温度升高而变得更好，其等温吸附数据可用Langmuir方程描述，热力学计算表明Cr(VI)的吸附是自发的吸热过程。溶液pH对CuO@D201吸附性能有较大影响，复合吸附剂更适合酸性环境下进行吸附。动力学实验表明，CuO@D201具有较快的吸附速率，在四个小时左右可以达到吸附平衡，准一级动力学方程可较好地拟合吸附动力学数据。共存阴离子对于CuO@D201复合吸附剂和D201的吸附量影响均不大，表明吸附剂具备良好的吸附选择性。吸附饱和的吸附剂可用氢氧化钠和氯化钠的混合溶液脱附，脱附后的吸附剂吸附容量基本没有损失，表明CuO@D201吸附剂可以循环使用。

关键词：六价铬 铜氧化物复合材料 吸附

Study on Removal of Cr(VI) from Water by cupric oxide nano-adsorbent

Abstract

Hexavalent chromium is a kind of heavy metal with great toxicity, which is harmful to living organisms and the environment due to its high solubility. In this paper, CuO@D201 was prepared by loading copper oxide onto large pore strongly alkaline anion exchange resin D201. Adsorption effect of adsorbent on hexavalent chromium ion in water was studied by controlling pH, competitive ion, temperature, time and other operating conditions. The results showed that at the same temperature, the adsorption capacity of CuO @d201 increased significantly compared with that of D201, and the adsorption effect of CuO @d201 became better with the increase of temperature. The isothermal adsorption data could be described by the Langmuir equation, and the thermodynamic calculation showed that Cr(VI) adsorption was a spontaneous heat absorption process. Solution pH has a great impact on the adsorption performance of CuO@D201, and the composite adsorbent is more suitable for adsorption in acidic environment. The kinetic experiment shows that CuO@D201 has a fast adsorption rate and can reach the adsorption equilibrium in about four hours. The quasi-first-order kinetic equation can well fit the adsorption kinetic data. Coexisting anions have little effect on the adsorption capacity of CuO@D201 composite adsorbent and D201, indicating that the adsorbent has good adsorption selectivity. The adsorbent with saturated adsorption can be desorbed with mixed solution of sodium hydroxide and sodium chloride, and the adsorption capacity of the adsorbent after desorption is basically no loss, indicating that CuO@D201 adsorbent can be recycled.

Key Words: Hexavalent chromium; Copper oxide composite materials; Adsorption

目 录

摘要 I

ABSTRACT II

第一章 绪论 1

1.1 铬的来源与危害 1

1.2 含铬废水的常用处理方法 1

1.2.1 吸附法 1

1.2.2 化学沉淀法 1

1.2.3 离子交换法 2

1.2.4 电解法 2

1.2.5 膜分离法 2

1.2.6 生物法 2

1.3 吸附法除铬研究进展 3

1.4 铜氧化物除铬 3

1.5 本课题的研究目标和研究内容 4

1.5.1 课题的研究目标 4

1.5.2 课题的研究内容 4

第二章 实验材料和方法 6

2.1 实验试剂及仪器设备 6

2.1.1 实验试剂 6

2.1.2 实验仪器设备 6

2.2 铜氧化物复合吸附剂的制备 7

2.3 铜氧化物复合吸附剂吸附性能评价 5

2.3.1 实验方法 7

2.3.2 分析方法 9

第三章 实验数据分析 10

3.1 吸附剂的表征 10

3.2 吸附等温实验 11

3.3 溶液pH对吸附量的影响 14

3.4 反应时间对吸附量的影响 15

3.5 溶液离子强度对吸附量的影响 17

3.6 竞争离子对吸附量的影响 17

3.7 静态脱附实验 18

第四章 结论与展望 20

4.1 结论 20

4.2 展望 21

参考文献 22

致谢 25

第一章 绪论

1.1 铬的来源与危害

废水中的铬主要来源于制革、电镀、颜料、化工、耐火材料、冶金等行业，主要是Cr(VI)和Cr(III)，而Cr(VI)因为溶解性更高因此毒性比三价铬更大，研究表明，六价铬化合物会对很多酶的生成体系有影响，对生物毒性很大，通过皮肤、呼吸、消化以及粘膜系统进入人体，经口、呼吸道或皮肤接触吸收后能引起“三致”作用[^[1]]。在自然环境下六价铬不容易被生物所分解，极易与其他物质形成稳定化合物进入水体，基于六价铬的危害性，其在全世界都被列入致癌物[^[2]]，对含铬废水的排放标准也日趋严格[^[3]]。

1.2 含铬废水的常用处理方法

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