论文总字数：21443字

摘 要

全国枸杞种植面积达215万亩以上，枸杞在生产及加工过程中每年产生超过90万吨的叶、柄、枝条等废弃物，大量的枸杞枝条及加工废弃物被焚烧、废弃，资源浪费严重，同时也污染环境。为减轻枸杞生产及加工废弃物对环境的污染，提高其资源化利用的效率及枸杞产业的附加值，本研究选取枸杞枝条为原料，在300 °C、350 °C、400 °C、450 °C、500 °C、550 °C和600 °C的条件下制备生物炭，并选取改性剂对生物炭进行改性，考察不同条件下获得的生物炭的性质及其对污水中COD的去除效果。结果表明，550 °C条件下制备的生物炭比表面积较大，孔隙结构丰富；选取了550 °C生物炭进行碱改性，改性后的生物炭比表面积和微孔都显著增加，改性后的生物炭对污水中COD的去除效率高达40%以上；后期将枸杞枝条生物炭粉末与铁粉等材料混合制备铁炭环境催化材料，并应用于难降解工业废水的预处理及现有污水处理厂的提标改造中。因此，将枸杞枝条开发成生物炭及环境催化材料是一种有前景的枸杞枝条高值化利用的方法。

关键词：生物炭 碱改性 比表面积 孔径分布

Abstract

In China, the planting area of Chinese wolfberry is over 2.15 million mu. During the production and processing of Chinese wolfberry, more than 900,000 tons of leaves, stalks, branches, and other wastes are produced annually. A large number of Chinese wolfberry branches and processing wastes are burned and discarded, resulting in serious waste of resources and environmental pollution. In order to alleviate the environmental pollution caused by the waste of Chinese wolfberry and improve the efficiency of its resource utilization with the added value of Chinese wolfberry industry, this study selected Chinese wolfberry branches as raw materials to prepare biochar under the conditions of 300 °C, 350 °C, 400 °C, 450 °C, 500 °C, 550 °C, and 600 °C, and selected modifiers to modify the biochar. The properties of biochar and its removal efficiency on COD in wastewater were investigated. The results showed that the specific surface area and pore structure of biochar prepared under 550 °C condition were large and abundant; biochar produced at 550 °C was selected for alkali modification, and the specific surface area and micropore of biochar after modification were significantly increased. The removal efficiency on COD in wastewater by modified biochar was up to 40%. Later, biochar powder prepared by Chinese wolfberry branches will be mixed with iron powder to prepare iron-carbon environmental catalysis. The material is also applied to the pretreatment of refractory industrial wastewater and the upgrading of existing sewage treatment plants. Therefore, the development of biochar and environmental catalytic materials from Chinese wolfberry branches is a promising method for its high value utilization.

Key Words: Biochar; Alkali modification; Specific surface area; Pore size distribution

目 录

摘要 I

ABSTRACT II

前言 1

第一章 文献综述 2

1.1生物炭的制备 2

1.2生物炭的改性 3

1.2.1氧化剂改性 3

1.2.2碱改性 3

1.2.3金属离子改性 4

1.3生物炭及改性生物炭的性质探究 4

1.4 污水COD及降解方法 5

第二章 实验材料与方法 6

2.1 实验材料与仪器 6

2.1.1实验材料 6

2.1.2实验仪器 6

2.1.3 实验试剂 6

2.2实验方法 7

2.2.1 生物质的预处理 7

2.2.2生物质的成分分析 7

2.2.3生物质的热重分析 7

2.2.4生物炭的制备 7

2.2.5 碱改性生物炭的制备 7

2.2.6 COD吸附试验 7

2.3 性质表征 8

第三章 实验结果与讨论 9

3.1生物质热解特性 9

3.2 生物炭性能分析 11

3.2.1 热解温度对生物炭产率的影响 11

3.2.2 热解温度对生物炭元素组成的影响 12

3.2.3 热解温度对生物炭比表面积及孔隙结构的影响 12

3.2.4 热解温度对表面官能团的影响 14

3.3 碱改性生物炭性能分析 16

3.4 COD吸附试验 17

第四章 结论与展望 19

参考文献 20

致谢 24

前言

全国枸杞种植面积约为215万亩，在种植和加工生产枸杞过程中会产生大量的叶、柄、枝条、枸杞子渣等废弃物，根据实际测算，宁夏回族自治区年枸杞生产加工废弃物产量达 20万吨以上，但这些废弃生物质资源仅有少量应用于防沙造林或者插扦育苗，大量被焚烧、废弃，不仅造成资源浪费，而且产生了二氧化硫、氮氧化物、二噁英等污染性气体，会加剧温室效应。为了解决枸杞生产加工废弃物资源浪费及不当处理引发的环境污染问题，有研究者提出了将其厌氧热解制备成生物炭的研究思路。

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