典型污泥EPS对重金属及相应纳米颗粒的吸附

发布时间：2018-01-05 14:16

本文关键词：典型污泥EPS对重金属及相应纳米颗粒的吸附　出处：《哈尔滨工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着社会科技的进步和城市现代化进程的加快,重金属及其纳米颗粒在工业、医疗等行业中的大量使用,不可避免的引发了严重的环境问题。目前,常采用生物工艺处理重金属废水及含有纳米颗粒的生活污水。污泥作为污水生物处理系统的主要组成部分,其沉降性能、脱水性能、生物絮凝以及表面特性在很大程度上受污泥胞外聚合物(EPS)的影响。目前,人们主要研究污泥EPS整体对于重金属离子及纳米颗粒的吸附特性,没有对污泥EPS进行组分分析,而且大多数研究都以活性污泥作为研究对象。因此,全面探究污泥EPS对重金属离子和纳米颗粒的吸附特性具有重要意义。本课题通过对活性污泥、厌氧颗粒污泥以及厌氧絮状污泥胞外聚合物(EPS)进行分级实验,分析其亲/疏水性组分并研究其物化特征。结果表明:三种污泥EPS中均主要含有芳香类物质及微生物代谢产物,对于蛋白质含量,厌氧絮状污泥最高,厌氧颗粒污泥次之,活性污泥最低;对于多糖、TOC及UV-254值,厌氧絮状污泥最高,活性污泥次之,厌氧颗粒污泥最低;污泥沉降性能与亲水性物质的含量呈正相关,脱水性能与疏水性物质的含量呈正相关。通过污泥EPS及其组分对Zn2+、Ti4+和Cu2+及其纳米颗粒的吸附实验研究其吸附特性。结果表明:对于同一种金属离子,厌氧颗粒污泥EPS吸附量最高,而厌氧絮状污泥EPS和活性污泥EPS相近;对于同一种纳米颗粒,活性污泥吸附量最高,厌氧絮状污泥次之,厌氧颗粒污泥最小;对于同一种污泥EPS,其对重金属离子的亲和力Cu2+Ti4+Zn2+,对纳米颗粒的亲和力为Ti O2Cu OZn O。通过厌氧颗粒污泥EPS与Zn2+、Ti4+和Cu2+及其纳米颗粒的吸附等温线及吸附动力学方程,研究其热力学及动力学特征。结果表明:Cu2+及其纳米颗粒与Ti4+的吸附适合用Freundlich等温吸附方程模拟。Zn2+及其纳米颗粒与纳米Ti O2适合用Langmuir等温吸附方程模拟。此外,厌氧颗粒污泥EPS与Cu2+、Zn2+和Ti4+及其纳米颗粒的吸附过程均适合用准二级反应动力学方程进行模拟,且吸附过程中均已化学吸附为主。通过红外光谱和扫描电镜,研究不同污泥EPS对Zn2+、Ti4+和Cu2+及其纳米颗粒的吸附机理。结果表明:污泥EPS是通过羟基、羧基、氨基、酰胺基团和C-O-C基团与Zn2+、Ti4+和Cu2+及其纳米颗粒发生作用。
[Abstract]:With the progress of social science and technology and the acceleration of urban modernization, heavy metals and their nanoparticles are widely used in industry, medical treatment and other industries, which inevitably lead to serious environmental problems. Biological process is often used to treat heavy metal wastewater and domestic sewage containing nanoparticles. Sludge is the main component of wastewater biological treatment system, its settling performance and dehydration performance. Biological flocculation and surface properties are largely affected by the extracellular polymer (EPS) of sludge. At present, the adsorption characteristics of sludge EPS for heavy metal ions and nanoparticles are mainly studied. There is no component analysis of sludge EPS, and most of the studies take activated sludge as the object of study. It is of great significance to study the adsorption characteristics of sludge EPS to heavy metal ions and nanoparticles. Anaerobic granular sludge and anaerobic flocculating sludge were classified by extracellular polymer (EPS). The hydrophilic / hydrophobic components were analyzed and their physicochemical characteristics were studied. The results showed that the three kinds of sludge EPS mainly contained aromatic substances and microbial metabolites, and the anaerobic flocculating sludge had the highest protein content. Anaerobic granular sludge was the second and activated sludge was the lowest. For polysaccharides TOC and UV-254, anaerobic flocculating sludge was the highest, activated sludge was the second, and anaerobic granular sludge was the lowest. Sludge settling property was positively correlated with hydrophilic substance content, dewatering property was positively correlated with hydrophobic substance content. Zn2 was analyzed by sludge EPS and its components. The adsorption characteristics of Ti4 and Cu2 and their nanoparticles were studied. The results showed that the adsorption capacity of EPS in anaerobic granular sludge was the highest for the same metal ions. However, EPS of anaerobic flocculating sludge was similar to EPS of activated sludge. For the same kind of nanoparticles, the adsorption capacity of activated sludge was the highest, the anaerobic flocculating sludge was the second, and the anaerobic granular sludge was the smallest. For the same sludge, its affinity to heavy metal ions was Cu2 Ti4 Zn2. The affinity to nano-particles was TIO _ 2Cu OZn _ O. EPS and Zn2 were used in anaerobic granular sludge. Adsorption isotherms and adsorption kinetics equations of Ti4 and Cu2 and their nanoparticles. The thermodynamic and kinetic characteristics of the solution were studied. The results show that the adsorption of Ti4 with Ti4 is suitable for Freundlich isothermal adsorption equation. Zn2. And nano-particles and nano-TiO _ 2 can be simulated by Langmuir isothermal adsorption equation. The adsorption process of EPS, Cu2, Zn2, Ti4 and their nanoparticles in anaerobic granular sludge is suitable to be simulated by quasi second-order reaction kinetics equation. The adsorption process was mainly chemisorbed. The effects of different sludge EPS on Zn2 were studied by infrared spectroscopy and scanning electron microscope. The adsorption mechanism of Ti4 and Cu2 and their nanoparticles. The results show that the sludge EPS is composed of hydroxyl, carboxyl, amino, amide and C-O-C groups with Zn2. Ti4 and Cu2 and their nanoparticles interact.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

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