论文总字数：15275字

摘 要

近些年来，我国畜牧养殖产业迅猛发展，导致具有预防病虫害功效的砷添加剂大量使用。添加剂经消化代谢后，大部分砷随粪便排出。粪便发酵后，其中的砷并未消失而富集于沼液中。在厌氧发酵环境下，砷元素在物理，化学，生物的作用下发生形态转化，使得毒性和生物学特性发生变化，因而存在进入食物链，危害人体健康，污染环境的危险。

TiO₂即可作为光催化剂氧化As(III)为As(V)，同时又可作为吸附剂除砷，但其吸附性能较差，分离困难，不易直接用于饮用水砷的处理。而ZIF-8具有稳定性好，比表面积大吸附性能强等特点，是除砷的理想吸附剂。所以结合TiO₂ 和ZIF-8的长处，将TiO₂负载到ZIF-8上，形成复合材料TiO₂@ZIF-8用于沼液中砷的处理。

在本次实验中，未处理沼液中总砷含量为64.71 ± 3.47 μg/L，超标倍数为0.29。经避光吸附，UV照射1h和光照2.5 h后，沼液中砷主要以AS(III) 的形态，存在有少量的As(V)和DMA。处理后总砷浓度为14.03±0.81 μg/L，去除率为78.3%，达到农田灌溉标准。

关键词： TiO₂@ZIF-8 砷 吸附 光催化

Photocatalytic treatment of arsenic in biogas slurry by TiO₂@ZIF-8

Abstract

In recent years, the rapid development of China's animal husbandry and aquaculture industry has led to the extensive use of arsenic additives that can prevent pests and diseases. After the additives are digested and metabolized, most of the arsenic is excreted in the feces. After the excrement was fermented, the arsenic did not disappear and accumulated in the biogas slurry. Under the anaerobic fermentation environment, arsenic elements undergo morphological transformation under the influence of physical, chemical, and biological factors, resulting in changes in toxicity and biological characteristics, and thus there is a risk of entering the food chain, endangering human health, and polluting the environment.

TiO₂ can be used as a photocatalyst to oxidize As(III) to As(V). At the same time, it can also be used as an adsorbent to remove arsenic, but its adsorption performance is poor, separation is difficult, and it is not easy to directly use for the treatment of drinking arsenic. ZIF-8 has the characteristics of good stability, large specific surface area and strong adsorption performance, and is an ideal adsorbent for arsenic removal. Therefore, combining the advantages of TiO₂ and ZIF-8, TiO₂ was loaded on ZIF-8 to form a composite TiO₂@ZIF-8 for the treatment of arsenic in biogas slurry.

In this experiment, the total amount of arsenic in the untreated biogas slurry was 64.71 ± 3.47 μg/L with a multiple of 0.29. After light absorption, UV irradiation for 1 h and light irradiation for 2.5 h, arsenic in biogas slurry mainly exists in the form of AS (III), and there is a small amount of As(V) and DMA. The total arsenic concentration after treatment was 14.03 ± 0.81 μg/L, and the removal rate was 78.3%, which reached the standard of farmland irrigation.

Keywords: TiO₂@ZIF-8； arsenic； adsorption； photocatalysis

目录

摘要 I

ABSTRACT Ⅱ

第一章 文献综述 1

1.1 前言 1

1.1.1沼液中砷污染概述 1

1.2砷处理技术研究与发展 1

1.2.1凝聚和絮凝法 1

1.2.2离子互换法 2

1.2.3膜分离法 2

1.2.4微生物法 3

1.2.5吸附法 3

1.3 TiO₂@ZIF-8介绍 3

1.4本课题的研究背景和内容 4

第二章 TiO₂@ZIF-8处理沼液中砷的实验 5

2.1 实验材料及方法 5

2.1.1 实验试剂 5

2.1.2 仪器设备 5

2.1.3 沼液样品及常规指标 7

2.1.4 沼液形态砷分析 9

2.1.5 合成TiO₂@ZIF-8 10

2.1.6 利用TiO₂@ZIF-8处理沼液中的砷 10

第三章 结果与讨论 10

3.1 结论 10

第四章 结论与展望 13

4.1 展望 13

参考文献 14

致 谢 17

第一章 文献综述

1.1 前言

1.1.1沼液中砷污染概述

砷（Arsenic）是一种有色泽的灰色元素,主要有4种价态：As(V)、As(III)、As(0)

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