纳米氧化锌及其复合材料光催化去除水中低浓度氨氮研究

发布时间：2018-01-06 07:36

  本文关键词：纳米氧化锌及其复合材料光催化去除水中低浓度氨氮研究　出处：《南京理工大学》2017年硕士论文　论文类型：学位论文

  更多相关文章： 光催化 纳米ZnO 聚甲基丙烯酸甲酯 氧化石墨烯 氨氮

【摘要】：农业污染造成污水中氨氮超标,过量的氨氮会引起水体富营养化,使藻类大量增殖,对水体生态平衡和人类健康产生严重的危害。本课题制备了 ZnO、ZnO-PMMA(基甲基丙烯酸甲酯)和Cu-ZnO-GO(氧化石墨烯)三种光催化材料,研究了催化材料对氨氮废水的去除效果。为纳米半导体光催化治理氨氮废水提供了理论依据。本课题主要从下列方面进行:(1)水热法制备ZnO,考察其光催化去除水中低浓度氨氮的能力,探究了光催化机理。纳米ZnO为六方晶系纤锌矿结构,结晶度好,光催化去除初始浓度为50 mg·L-1的氨氮废水,125W汞灯365 nm光照作用下,催化剂用量为2.0g·L-1 pH=10.0,温度30℃,光照4 h,氨氮去除率可达64.8%,反应产物大部分为氮气。(2)水热法制备ZnO,通过热粘固法制得ZnO-PMMA复合材料,考察其光催化去除水中低浓度氨氮的能力。在125 W汞灯紫外光照作用下,复合材料ZnO-PMMA去除初始浓度为50mg.L-1的氨氮废水,催化剂用量为1.0g.L-1 pH=10.0,温度30℃,光照4 h,氨氮去除率可达66%。PMMA与纳米ZnO具有协同效应,提高了分散性和紫外光利用率,材料回收简单,重复利用性好,相同条件下对氨氮的去除率从41%提高到66%。(3)两步水热法制备Cu-ZnO-GO复合材料,考察其光催化去除水中低浓度氨氮的能力。在3盏30 W日光灯下,Cu-ZnO-GO去除初始浓度为50 mg·L-1的氨氮废水,催化剂用量为2.0g·L-1 pH=10.0,温度30℃,光照2h,氨氮去除率可达79.6%,相同条件下ZnO和Cu-ZnO分别为13.3%、48.1%。Cu掺杂拓宽其光响应范围,GO的负载提高了催化性能,为ZnO相关材料处理实际污水中的氨氮提供了必要的基础。
[Abstract]:Agricultural pollution caused excessive ammonia nitrogen in sewage, excessive ammonia nitrogen will cause eutrophication of water body, make algae proliferate, and cause serious harm to water ecological balance and human health. ZnO was prepared in this paper. ZnO-PMMA (methyl methacrylate) and Cu-ZnO-GOO (graphene oxide) are photocatalytic materials. The removal efficiency of ammonia nitrogen wastewater by catalytic materials was studied, which provided a theoretical basis for the photocatalytic treatment of ammonia nitrogen wastewater by nanometer semiconductor. In this paper, ZnO was prepared by hydrothermal method from the following aspects. The photocatalytic removal of ammonia nitrogen from water was investigated and the photocatalytic mechanism was investigated. The nanocrystalline ZnO is hexagonal wurtzite structure with good crystallinity. Photocatalytic removal of NH _ 3-N wastewater with initial concentration of 50 mg 路L ~ (-1) was carried out under the irradiation of 125 W Hg lamp at 365 nm, and the amount of catalyst was 2.0 g 路L ~ (-1) pH=10.0. At 30 鈩，

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