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毕业论文网 > 毕业论文 > 环境科学与工程类 > 环境科学 > 正文

硫酸改性天然锰氧化物去除双酚A机理研究毕业论文

 2022-01-14 09:01  

论文总字数:25771字

摘 要

新兴污染物是一大类在环境中存在浓度较低,人们早前可能已经认识但一直没有足够关注,且对人体和生态系统存在较大威胁的污染物。主要由日常用品及工业添加剂(比如药品、护理用品、阻燃剂等)构成。尽管这些污染物的浓度普遍较低,但仍显示出一定的环境影响,比如会对生物体的内分泌活动产生干扰。因此,关于新兴污染物的去除技术有很大的研究必要。

天然锰氧化物是自然环境中含量丰富且具有较高氧化能力的天然氧化物,并且是土壤的重要组成部分,但其表面复杂的成分会抑制其氧化性。本课题利用硫酸对锰矿石改性,以提高其氧化能力,双酚A作为模型污染物,研究其降解过程。分别探究了反应体系pH、硫酸改性锰矿石(S-MnOx)的投加量、双酚A初始浓度三种影响因素对反应中双酚A去除率的影响。

实验结果显示:随着反应体系pH值的逐渐升高,双酚A的去除率明显减慢。当反应pH=3,反应7小时后,双酚A的去除率达到94.39%;随着硫酸改性锰矿石投加量的逐渐增大,双酚A的去除效率明显加快;当改性锰矿石的投加量为5g/L及双酚A初始浓度为5mg/L时,双酚A去除率在反应1h后全都达到了90%。因此,硫酸改性锰矿石投加量越多,而双酚A的初始浓度越低,去除效果就越好。在对以上三种影响因素进行综合分析后,得到了最佳效果的反应条件:即反应体系pH=3,天锰矿石投加量为5g/L,双酚A初始浓度为5mg/L时,双酚A的降解效果比较好。通过对双酚A去除率的动力学方程拟合发现,上述三个参数的一级、二级动力学均能较好地描述双酚A去除率随时间的变化,其中一级动力学拟合度均超过0.9583,二级动力学拟合度均超过0.9591。

关键词:硫酸改性锰矿石 双酚A 动力学

Degradation mechanism of bisphenol A with modified natural manganese oxides by sulfuric acid

Abstract

Emerging pollutants are a large category of pollutants that are less concentrated in the environment and that may have been known earlier but have not been sufficiently concerned and pose a greater threat to the human body and ecosystems. Emerging pollutants are mainly made up of daily necessities and industrial additives (such as pharmaceuticals, nursing supplies, flame retardants, etc.). Although the concentrations of these pollutants are generally low, they still show some environmental effects, such as interference with the endocrine activity of organisms. Therefore, the research for removal technology of emerging pollutants is necessary.

Natural Manganese oxide is a natural oxide with abundant content and high oxidation ability in natural environment, and it is an important part of soil, but its surface complex components can inhibit its oxidation. In this paper, sulfuric acid was modified to manganese ore to improve its oxidation capacity, bisphenol A as a model pollutant, and the degradation process was studied. The effects of three factors that the reaction system pH, added dosage of S-MnOx and the initial concentration of bisphenol A on the removal rate of bisphenol A in the reaction system were investigated.

The results of the study show that: the removal rate of bisphenol A slows down obviously with the increase of pH value in the reaction system. The removal rate of bisphenol A reached 94.39%(pH=3,t=7h), and with the increase of the addition of modified manganese oxide with sulfuric acid, the removal efficiency of bisphenol A was obviously accelerated, and when the dosage of S-MnOx was 5g/L and the initial concentration of Bisphenol A was 5mg/L, the removal rate of bisphenol A reached 90% after 1h. Therefore, the more the dosage of S-MnOx, and the lower the initial concentration of Bisphenol A, the better the removal effect. After comprehensive analysis of the above three influencing factors, the reaction conditions for the optimal results were obtained: that is, pH=3, the dosage of S-MnOx was 5g/L, and the degradation effect of bisphenol A was better with the initial concentration of Bisphenol A was 5mg/L. Through the fitting of kinetic equations, it is found that the kinetic process of the removal rate of bisphenol A by the above three parameters follows the kinetic equations of primary and two levels, and the first level kinetic fitting degree is more than 0.9583, The kinetic fitting degree of level two was more than0.9591.

Key Words: Modified manganese oxide with Sulfuric Acid; Bisphenol A; Dynamics

目 录

摘要 I

Abstract II

第一章 绪论 1

1.1 研究背景 1

1.2 新兴污染物概述 1

1.2.1 新兴污染物的来源与分类 1

1.2.2 含双酚A废水的基本性质 2

1.2.3 含双酚A废水的生态影响 2

1.2.4 含双酚A废水的环境归趋 3

1.2.5 含双酚A废水常用去除技术概述 4

1.3 锰氧化物的概述 5

1.3.1 天然锰矿石概述 5

1.3.2 锰氧化物的氧化降解效果 5

1.3.3 锰氧化物降解有机物的研究进展 5

1.4 研究目的、意义及主要内容 6

第二章 实验材料及内容 7

2.1 实验仪器及设备 7

2.2 实验试剂 7

2.3 实验材料及溶液配制 7

2.4 实验方法 8

2.4.1 天然锰矿石改性条件的筛选 8

2.4.2 硫酸改性锰矿石去除BPA实验 8

2.5 计算方法与公式 9

第三章 实验结果与讨论 13

3.1 天然锰矿石改性条件的筛选 13

3.2 BPA去除率影响因素的分析 14

3.2.1 反应体系pH 14

3.2.2 硫酸改性锰矿石的投加量 15

3.2.3 BPA初始浓度 16

3.3 BPA去除动力学 17

3.3.1 反应体系pH 18

3.3.2 硫酸改性锰矿石的投加量 19

3.3.3 BPA初始浓度 20

第四章 结论与展望 21

参考文献 22

致谢 25

第一章 绪论

研究背景

水是生物体的重要组成成分,也是人类社会赖以生存和发展的重要自然资源。地球表面有71%的面积为水所覆盖,总的水储量大约有13.8×108km3,其中海水储量占总储水量的97.5%,淡水储量只占2.5%,而且绝大部分的淡水是以地下水和极地冰川的形式存在,难以被人类直接利用[1]。我国的河川径流总量虽然位居世界第六位,但人均量仅为世界均值的28%。

改革开放之后,我国的第二产业飞速发展,但过快的工业发展也给我国的生态环境带来了严峻的考验。根据《中国环境统计年报·2015》数据显示,我国2015年的废水排放总量计735.3亿吨。其中,工业废水排放量达199.5亿吨,占废水排放总量的27.1%,比2014年减少了1.6%[2]。

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