海洋生态与环境科学重点实验室知识库

有害藻华是一类典型的海洋生态灾害，严重威胁着海洋生态健康，近年来，人类活动的加剧导致有害藻华暴发次数和面积逐年提升，人们对藻华灾害的全面监测、及时预警和应急处置提出了更高的要求。改性粘土法是一种有效的有害藻华应急处置方法，进一步提高其治理效能一直是该领域的研究热点。本研究采用复合方法强化改性粘土的絮凝作用，融合铁系与铝系絮凝剂的优点，将聚合氯化铝和氯化铁复合，考察了铁铝复合改性粘土的除藻机制，研发不同Fe含量的铁铝复合改性粘土，以期提高铝系改性粘土的絮凝除藻能力。另外，针对有害藻华治理研究中存在实验室用量与现场用量表征不相同问题，进行了改性粘土室内用量和现场用量转换关系的初步探究。上述研究为改性粘土应急消除有害藻华的进一步推广应用提供参考。主要结果如下：

（1）考察了铁铝复合改性粘土对东海原甲藻(Prorocentrum donghaiense)、赤潮异弯藻(Heterosigma akashiwo)、塔玛亚历山大藻(Alexandrium tamarense)和微绿球藻(Nannochloris oculata)的去除效率。结果表明，铁盐的引入对铝系改性粘土去除藻华生物的效率具有提升作用，该作用随Fe含量的增加而增大，最高可达20%-30%。通过现场实验，验证了复合改性粘土的除藻效果，并发现铁系改性粘土更适合用于对微微型藻的去除，相比铝系改性粘土，对微微型藻的去除效率最高可提升30%-40%。

（2）本研究采用扫描电镜、Zeta电位仪和粒子成像测速仪测定了复合改性粘土在海水中的形貌特征、表面特征和絮体特性。结果表明，铁铝复合改性粘土体系中，随Fe含量的增多，铁铝复合改性粘土表面正电位最高可提升15%，有效提升对藻细胞的电中和作用；改性粘土絮体的稳定絮凝体指数(γ)降低，絮体强度增加，从而增强了改性粘土的絮体稳定性；并且改性粘土絮体结构从松散网状结构转变为密实片状结构，有效提升对藻细胞的包埋效果。

（3）实验室和现场分别采用体积浓度和单位面积喷洒量来表示改性粘土的有效用量，如何转换这两者之间的关系呢？本文设计了不同高度和不同面积的容器，探讨了藻细胞不同分布高度和分布面积对改性粘土絮凝效率的影响。研究发现，在体积浓度和单位面积喷洒量两种用量方法下，藻液面积和藻细胞去除率的关系均为减速增长曲线，可用非线性方程来定量描述；对比室内试管实验，模拟现场实验拟合方程的转换结果与室内实验结果相吻合，证明可以通过藻细胞分布面积来进行实验室与现场用量的转换。

Harmful algal blooms seriously threaten the health of marine ecology. In recent years, the increase in human activities has led to an increase in the number and area of harmful algal blooms. People have put forward higher requirements for the comprehensive monitoring, timely warning and emergency response of algal bloom disasters. Modified clay method is an effective emergency treatment method for harmful algal blooms, and further improving its treatment efficiency has always been a research hotspot in this field. This study uses a composite method to strengthen the flocculation of the modified clay, combines the advantages of iron-based and aluminum-based flocculants, combines polyaluminum chloride and ferric chloride, investigates the algae removal mechanism of the iron-aluminum composite modified clay, and develops different Fe-content iron-aluminum composite modified clay, in order to improve the flocculation and algae removal ability of aluminum-based modified clay. In addition, in view of the different characterization of laboratory dosage and field dosage in the study of harmful algal bloom treatment, a preliminary study on the conversion relationship between indoor dosage and field dosage of modified clay was carried out. The above research provides reference for the further popularization and application of modified clay to eliminate harmful algal blooms. The main results are as follows:

(1) The removal efficiency of the iron-aluminum composite modified clay on Prorocentrum donghaiense, Heterosigma akashiwo, Alexandrium tamarense and Nannochloris oculata was investigated. The results show that the introduction of iron salt can improve the efficiency of aluminum-based modified clay to remove algal blooms, and this effect increases with the increase of Fe content, up to 20%-30%. Field experiments have verified the algae removal effect of the composite modified clay, and found that the iron-based modified clay is more suitable for the removal of microalgae. Compared with the aluminum-based modified clay, the removal efficiency of the microalgae is the highest. Increase by 30%-40%.

(2) In this study, scanning electron microscopy, Zeta potential meter and particle imaging velocimetry were used to determine the morphological characteristics, surface characteristics and floc characteristics of the composite modified clay in seawater. The results show that in the iron-aluminum composite modified clay system, with the increase of Fe content, the positive potential of the surface of the iron-aluminum composite modified clay can be increased by up to 15%, which effectively enhances the electric neutralization effect on algae cells; The stable floc index (γ) decreases and the floc strength increases, thereby enhancing the stability of the modified clay floc; and the modified clay floc structure is transformed from a loose network structure to a dense flake structure, which effectively improves the effect on algae cells. The embedding effect.

(3) The laboratory and the field use volume concentration and spray amount per unit area respectively to express the effective dosage of modified clay. How to convert the relationship between the two? In this paper, containers with different heights and different areas are designed, and the influence of different distribution heights and distribution areas of algae cells on the flocculation efficiency of modified clay is discussed. The study found that under the two dosage methods of volume concentration and spraying amount per unit area, the relationship between the area of algae liquid and the removal rate of algae cells is a decelerating growth curve, which can be quantitatively described by a nonlinear equation; compare the indoor test tube experiment and simulate the field experiment. The conversion results of the combined equations are consistent with the results of indoor experiments, which proves that the conversion between laboratory and field consumption can be carried out through the distribution area of algae cells.

摘 要... I

ABSTRACT. III

第一章  引言... 1

1.1 有害藻华现象及防治研究进展... 1

1.1.1 富营养化与有害藻华... 1

1.1.2 有害藻华危害及防治方法... 2

1.2 改性粘土治理有害藻华研究进展... 6

1.2.1 改性粘土絮凝模型及理论... 6

1.2.2 改性粘土除藻机制与絮凝特征... 7

1.2.3 改性粘土分类... 10

1.3 铁系絮凝剂及絮凝强化技术... 11

1.3.1 铁盐絮凝剂种类... 11

1.3.2 Fe(III)水解特性... 12

1.3.3 絮凝强化技术... 13

1.4 本研究的内容、目标和意义... 14

第二章  铁系絮凝剂对铝系改性粘土除藻效果的提升研究... 17

2.1 前言... 17

2.2 材料与方法... 18

2.2.1 室内实验材料... 18

2.2.2 现场实验区域及材料... 20

2.2.3 实验方法... 22

2.3 结果与讨论... 23

2.3.1 铁盐对铝系改性粘土除藻效率提升的影响... 23

2.3.2 不同类型铁盐絮凝剂对改性粘土除藻效率的影响... 27

2.3.3 铁铝复合改性粘土对水体pH的影响... 29

2.4 小结... 29

第三章  铁铝复合改性粘土去除藻华生物的机制初探... 31

3.1 前言... 31

3.2 材料与方法... 32

3.2.1 实验材料... 32

3.2.2 实验方法... 33

3.3 结果与讨论... 34

3.3.1 铁铝复合改性粘土颗粒表面Zeta电位变化及其水解作用... 34

3.3.2 东海原甲藻藻细胞-改性粘土絮团结构... 36

3.3.3 铁铝复合改性粘土对絮体粒径变化的影响... 38

3.3.4 铁铝复合改性粘土对絮体强度及絮体恢复能力的影响... 39

3.4 小结... 42

第四章  改性粘土实验室与现场用量转换方法初探... 43

4.1 前言... 43

4.2 材料与方法... 43

4.2.1 实验材料... 43

4.2.2 实验方法... 44

4.3 结果与讨论... 45

4.3.1 藻细胞分布对改性粘土除藻效率的影响... 45

4.3.2 改性粘土实验室与现场用量的转换关系探讨... 49

4.4 小结... 51

第五章  总结和展望... 53

5.1 结论... 53

5.2 不足与展望... 54

参考文献... 55

致 谢... 67

作者简历及攻读学位期间发表的学术论文与研究成果... 69