论文总字数：23617字

摘 要

随着土壤重金属污染对人类健康和环境的危害日益显著，重金属污染土壤修复也越来越受人关注。在多种重金属污染土壤修复技术当中，原位固定/稳定化修复技术因为具有价格低廉、操作简便、环境友好的优点，应用潜力巨大，引起了人们的广泛研究。而选择合适的固定剂是研究原位固定/稳定化修复技术的重点。

目前，对于土壤各种金属污染原位固化技术的研究已经较为成熟，但大多研究只针对使用单一固化剂的情况。而在应用中，由于土壤污染多数是多种重金属离子复合导致的，施用单一固化剂修复效果并不理想。因此，已经有部分人员开展了对复合类固化剂的研究。研究表明，复合类固化剂的修复效果明显优于单一固化剂。但是，目前的研究，一是大多数是研究复合材料的结构性质和去除水体中污染物；二是大多数集中于无机氧化物材料和纳米材料与生物炭的复合，对其他材料研究不多。

生物炭和黏土类天然矿物材料（例如羟基磷灰石、高岭土、凹凸棒土、海泡石、硅藻土、磷酸二氢钙等），对重金属的吸附效果优良，且对环境无害，价格友好，量大易得，是热门的固定剂。因此，本论文重点围绕黏土-生物炭复合材料展开研究。本次研究的内容包括：将不同的黏土矿物和生物炭复合并且制备出黏土-生物炭固化剂，随后通过批量吸附实验筛选出高效的吸附剂。将所选出效果最好的复合材料加入到铜、铅单一污染土壤和铜铅复合污染土壤中，探究投加量和金属初始浓度对固化的影响，研究固化机理。

所得到的结论有：（1）在对高岭土、凹凸棒土、硅藻土、蒙脱石粉、海泡石、羟基磷灰石与生物炭复合材料进行液相吸附实验时，无论是单组份还是双组份吸附，对Cu² 还是Pb² ，都是羟基磷灰石复合材料的吸附量最大，去除率也最高，而且羟基磷灰石复合材料对Pb² 的吸收高达100%；而高岭土、凹凸棒土、硅藻土、蒙脱石粉、海泡石复合材料虽然吸附效果略有差别，但相差不多。

（2）在对高岭土-商业稻壳炭、海泡石-商业稻壳炭、凹凸棒土-商业稻壳炭、蒙脱土-商业稻壳炭、羟基磷灰石-竹粉、羟基磷灰石-商业稻壳炭和羟基磷灰石-稻壳对实际污染土壤的研究中，这六种复合材料中羟基磷灰石-竹粉固化效果最好，这与液相吸附实验中选出的最优材料一致。

（3）以模拟污染土探究初始土壤重金属浓度和复合材料投加比对固化效果影响时，随着初始金属离子浓度上升，固化效果下降；而固化剂添加量越高，固化效果越好。

关键词：原位固化/稳定化，黏土-生物炭，铜，铅

Abstract

As the heavy metal pollution in the soil has become more and more harmful to human health and the environment, the remediation of heavy metal-contaminated soil has attracted more and more attention. Among the various heavy metal-contaminated soil remediation technologies, the in-situ chemical immobilization technology has the advantages of low cost, easy operation, and environmental friendliness, and has great potential for application, and has caused widespread research. The selection of suitable fixatives is the focus of studies on in situ chemical immobilization techniques.

At present, the research on the in-situ solidification technology of various metal contaminations in soil has been relatively mature, but most researches only focus on the use of a single curing agent. In application, due to soil contamination mostly caused by multiple ion recombination, the effect of applying a single curing agent is not satisfactory. Therefore, some people have carried out research on composite curing agents. Studies have shown that the curing effect of compound curing agents is significantly better than that of a single curing agent. However, the current research, first, most of them are to study the characterization of structural properties of composite materials and remove contaminants in water bodies; the second is that most of them are concentrated on the composite of inorganic oxide materials and nano-materials and biochar, and there is not much research on other materials. .

Biochar and clay-based natural mineral materials (eg, apatite, hydroxyapatite, kaolin, attapulgite, sepiolite, diatomaceous earth, calcium dihydrogen phosphate, etc.) have excellent adsorption effects on heavy metals, and are environmentally friendly. It is harmless, price-friendly, and easy to obtain. It is a popular fixative. Therefore, this paper focuses on the development of clay-biochar composites. The contents of this study include: combining different clay minerals with biochar and preparing a clay-biochar curing agent, followed by a batch adsorption experiment to screen out highly efficient adsorbents. The selected composite material with the best effect was added to copper, lead single-contaminated soil and copper-lead composite pollution soil. The influence of the amount of dosing and initial concentration of metal on curing was investigated, and the curing mechanism was studied.

The following conclusions are obtained: (1) In the adsorption experiments of kaolin, attapulgite, diatomite, montmorillonite, sepiolite, and hydroxyapatite, whether single-component or two-component adsorption For both Cu2 and Pb2 , hydroxyapatite has the highest adsorption capacity and the highest removal rate, and hydroxyapatite absorbs Pb2 up to 100%; while kaolin, attapulgite, diatomite, montmorillonite powder Although the absorption effect of sepiolite is slightly different, it is similar.

(2) Kaolin - commercial rice husk charcoal, sepiolite - commercial rice husk charcoal, attapulgite clay - commercial rice hull charcoal, montmorillonite - commercial rice husk charcoal, hydroxyapatite - bamboo powder, hydroxyapatite - Commercial rice husk charcoal and hydroxyapatite-rice husk have the best curing effect of hydroxyapatite-bamboo powder in these six composite materials, which is consistent with the optimal material selected in liquid phase adsorption experiments.

(3) When investigating the effect of initial soil heavy metal concentration and composite material addition ratio on curing effect, the curing effect decreases with the increase of initial metal ion concentration, and the higher the repair agent addition ratio, the better the curing effect.

KEY WORDS: In-situ curing/stabilization, clay-biochar, copper, lead

目录

摘要 I

Abstract III

第一章 绪论 1

1.1 土壤重金属污染 1

1.1.1 土壤重金属污染危害和污染现状 1

1.1.2 土壤重金属污染修复技术 2

1.2 重金属污染土壤原位钝化修复技术 4

1.3 钝化剂种类 4

1.4 本文研究内容及目的 5

第二章 黏土-生物炭对铅铜离子在水相中的吸附研究 6

2.1 主要仪器设备及药品 6

2.2 实验方法设计 6

2.2.1 重金属溶液的配置 6

2.2.2 黏土－生物炭的制备 6

2.2.3 批量吸附实验 6

2.2.4 重金属金属检测方法 6

2.3 实验结果与讨论 7

第三章 黏土-生物炭对实际污染土壤的固化研究 9

3.1 污染土壤采集和保存 9

3.2 主要仪器设备及药品 9

3.3 实验方法设计 9

3.3.1 重土壤总量消解 9

3.3.2 黏土－生物炭的制备 10

3.3.3 土壤固化试验 10

3.3.4 TCLP毒性浸出试验 10

3.4 实验结果与讨论 10

第四章 黏土-生物炭对模拟土壤的固化研究 12

4.1 供试土壤采集与保存 12

4.2 主要仪器设备及药品 12

4.3 实验方法设计 12

4.3.1 模拟污染土配制 12

4.3.2 重土壤总量消解 12

4.3.3 固化试验 13

4.3.4 TCLP毒性浸出试验 13

4.4 实验数据及分析 13

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