摘要:在发展中的国家,例如中国,来自工业排放的磷是造成水体富营养化的主要原因之一。在近期的研究中,我们提出了一种新的除磷的方法:将HFO负载于大孔型阴离子交换树脂NDA-201,制得一种复合吸附剂NDA201-HFO,加强对水体系统中磷的去除。研究表明,在NDA201-HFO对磷的去除过程中包含两个吸附点,一种是连在NDA-201上的季铵基团,另一种是负载在母体上的HFO纳米颗粒。共存的硫酸根对季铵基团有很强的竞争作用(影响树脂对磷的交换作用)。但是负载在NDA-201的HFO对磷酸根的吸附基本上不受硫酸根的影响,主要因为HFO对磷酸根的吸附通过内配位络合作用,对模拟含磷废水的柱吸附实验结果表明,在其他竞争离子共存的情况下,由NDA201-HFO处理过的含磷废水的磷的浓度由2mg/L降低到0.01mg/L,处理量达到700BV,而NDA-201处理量不到200BV。对于复合材料这种理想的处理效果归功于HFO对磷的特殊吸附以及骨架所带荷电基团产生的Donnan膜效应。吸附饱和的NDA201-HFO通过NaOH-NaCl洗脱可以有效的再生和重复利用,但性能,吸附量基本不受影响。通过使用含磷的工业废水当做消耗溶液也可以发现类似结果。60020
毕业论文关键词:水合氧化铁,复合吸附剂,磷
Abstract:One of the key factors responsible for eutrophication of the receiving waterways especially in the developing countries is phosphate originated from industrial effluents . Recently we proposed a novel process to immobilize nanoparticulate hydrated ferric oxide (HFO) within a macroporous anion exchange resin NDA-201, and obtained a hybrid adsorbent (NDA201-HFO) for strengthened phosphate removal from aqueous system. The resulting NDA201-HFO possesses two types of adsorption sites for phosphate removal, the ammonium groups link to the NDA-201 matrix and the loaded HFO nano-particles. The coexisting sulfate anion strongly fights for ammonium groups, which bind phosphate through electrostatic interaction. However, it does not cause any noticeable effect on phosphate adsorption by the loaded HFO nanoparticles, which is driven by the formation of the inner-sphere complexes. Fixed-bed column tests indicate that phosphate retention by NDA201-HFO from the synthetic waters causes the significant decrease of P from 2 mg/L to less than 0.01 mg/L, with the treatment capacity of w700 bed volume (BV) per run, while that for NDA-201 was less than 200 BV under otherwise identical conditions. Such satisfactory performance of the hybrid adsorbent is mainly attributed to the specific affinity of HFO toward phosphate as well as the Donnan membrane effect exerted by the anion exchanger support NDA-201. Moreover, the exhausted NDA201-HFO was assemble to efficient in situ regeneration with a binary NaOH–NaCl solution for repeated use without any important capacity loss. Similar satisfactory results were also observed by using a phosphate-containing industrial effluent as the feeding solution.
Keywords:hybrid absorbent,hydrated ferric oxide,Phospate
目 录
1 前言 4
2 实验材料与方法 5
2.1 试剂 5
2.2仪器 5
2.3 NDA201-HFO的制备 5
2.4 实验方法 6
2.5 实验结果与讨论 7
2.5.1 pH值的影响 7
2.5.2 吸附动力学 9
2.5.3 竞争吸附实验 10
2.5.4 吸附等温线 10
2.5.5 柱吸附- 脱附实验