实验海洋生物学重点实验室知识库

生物滤器是RAS中核心的水处理单元之一，是循环水养殖系统成功运行的关键，对于养殖水体的净化和循环再利用起到关键作用。传统的浸没式生物滤器虽具有截留悬浮物的功能，但是因容易被堵塞、水流分布不均匀造成乏氧区、老化菌膜不易排除等缺点，限制了其广泛使用。本试验采用一种新型的带有截污功能的自洁生物滤器，其不仅具有悬浮物截留功能，还可以通过自清洗功能克服上述缺点。本实验针对自洁生物滤器，研究不同挂膜方法、不同的自清洗频率、不同生物滤器进出水口流量、不同除污精度以及不同的填料填充率对生物滤器的水处理效果进行研究，取得的主要研究结果如下：

（1） 与自然挂膜相比，添加不同比例成熟生物膜能有效的降低氨氮和亚硝酸盐氮的浓度。自然挂膜（S1）在第15天达到的最高氨氮浓度为1.2 mg/L、添加10%成熟菌膜（S2）在第13天达到的最高氨氮浓度为0.55 mg/L和添加30%成熟菌膜（S3）在第13天达到的最高氨氮浓度为0.36 mg/L；S1处理组在第27天达到的最高亚硝酸盐氮浓度为4.6 mg/L，S2处理组在第15天达到的最高亚硝酸盐氮浓度为0.72 mg/L，S3处理组在第9天达到的最高亚硝酸盐氮浓度为0.35 mg/L，三个处理组的氨氮和亚硝酸盐氮浓度达到最高浓度的时间依次滞后。S1处理组、S2处理组和S3处理组生物膜成熟的时间分别为35天、25天和18天，数据表明添加成熟生物膜的比例越高，挂膜时间越短。在氨氮浓度下降和亚硝酸盐氮浓度下降时分别取样进行微生物测序，在门水平上主要含变形菌门、厚壁菌门、绿菌门、放线菌门、浮霉菌门和拟杆菌门，且菌门占比比例依次减小。亚硝酸盐氮下降时样品的变形菌门相比于氨氮浓度下降时样品的占比减小，而绿菌门、放线菌门和浮霉菌门占比升高。

（2）通过设计清洗频率为0.5次/d、1次/d和2次/d三个处理组，研究清洗频率对生物滤器的水处理影响。结果显示三个处理组均能将氨氮和亚硝酸盐氮降低到较低水平，无明显差异。但清洗频率为2次/d的处理组能显著将固体悬浮物排出系统，且相比另外两个处理组显著降低了系统中的硝酸盐氮含量，而硝酸盐氮作为氮的最终产物，其含量的减少说明系统中氮含量减少，减轻了循环水系统的水处理负荷。因此，综合清洗频率对自洁生物滤器的硝化性能和截污能力的影响，应适当增加生物滤器的清洗频率，在本实验条件下自洁生物滤器自清洗频率2次/d效果较好。

（3）不同流量循环水系统水处理能力不同，在将流量控制在1200 L/h和1500 L/h时有利于维持微生物与养殖水体的接触时间，因此生物滤器具有较好的水处理能力，能及时将氨氮和亚硝酸盐氮转化为养殖生物不敏感的硝酸盐氮，其中流量在1200 L/h（113 个循环量/h）的条件下，化学需氧量的去除量高于流量为900 L/h（1个循环量/h），但和1500 L/h（123 个循环量/h）条件下相比无显著性差异。因此，通当流量达到1200 L/h以上时效果不显著，将流量控制在1200 L/h条件是较好的流量参数。

（4）微滤机的过滤效果与其网目大小有关，微滤机的网目越大，其可滤除的颗粒物含量越多，净水能力也就越强，本实验网目为250目的条件下微滤机的过滤效果优于比120目和200目， 通过250目的微滤机去除大量的固体颗粒物，减少了养殖水体进入生物滤器携带的颗粒物含量，进而显著降低了水体中氨氮和亚硝酸盐氮以及化学需氧量的浓度，提高了自洁生物滤器的水处理能力。

（5）填料的填充率影响生物滤器的处理水处理能力，S2（75%填充率）和S3（100%填充率）填料料层厚度较大，截留较多的颗粒物，自清洗时能排出较多的颗粒物，从而使系统中总固体悬浮物小于S1（50%填充率）处理组，S1处理组化学需氧量浓度高于S2和S3处理组，且S2和S3处理组差异性不明显。S1处理组的氨氮和亚硝酸盐氮浓度显著大于S2和S3，但S2和S3处理组氨氮和亚硝酸盐氮浓度差异性不显著，综合以上，选择填充率为75%是较好的填充率参数。

本实验研究结果对工业化循环水养殖顺应时代发展的需要向着生态化发展具有推动作用，也为形成更加节水、高效的循环水系统提供理论基础。

Biological filter is one of the core water treatment units in RAS, is the key to the successful operation of circulating aquaculture system, and plays a key role in the purification and recycling of aquaculture water. Although the traditional submerged biological filter has the function of intercepting suspended solids, its shortcomings such as being easily blocked, uneven distribution of water causing anoxic zone, and difficult removal of aging bacterial membranes, restrict its wide use. This experiment uses a new type of self-cleaning biological filter with dirt interception function, which not only has the function of intercepting suspended solids, but also can overcome the above shortcomings through the self-cleaning function. This experiment is aimed at the self-cleaning biological filter, and studies the water treatment effect of the biological filter by different filming methods, different self-cleaning frequencies, different N concentration potentials at the inlet and outlet of different biological filters, different decontamination precisions, and different filler filling rates. The main research results obtained are as follows:

(1) Compared with natural film, adding different proportions of mature biofilm can effectively reduce the concentration of ammonia nitrogen and nitrite nitrogen. The highest ammonia nitrogen concentration reached by the natural membrane (S1) on the 15th day is 1.2 mg/L, the highest ammonia nitrogen concentration reached by the addition of 10% mature bacterial membrane (S2) on the 13th day is 0.55 mg/L and the addition of 30% mature bacteria The membrane (S3) reached the highest ammonia nitrogen concentration on the 13th day of 0.36 mg/L; the S1 treatment group reached the highest nitrite nitrogen concentration on the 27th day of 4.6 mg/L, and the S2 treatment group reached the highest on the 15th day The concentration of nitrite nitrogen was 0.72 mg/L, the highest concentration of nitrite nitrogen reached by the S3 treatment group on the 9th day was 0.35 mg/L, the time for the ammonia nitrogen and nitrite nitrogen concentrations of the three treatment groups to reach the highest concentration in sequence Lag. The maturation time of the biofilms in the S1 treatment group, S2 treatment group and S3 treatment group were 35 days, 25 days and 18 days, respectively. The data showed that the higher the proportion of mature biofilms, the shorter the time for the membrane to hang. Samples were taken for microbial sequencing when the ammonia nitrogen concentration decreased and the nitrite nitrogen concentration decreased. At the phylum level, it mainly contains the Proteobacteria, Firmicutes, Chlorophyta, Actinomycetes, Planktomycetes and Bacteroides. And the proportion of bacteria phyla decreased successively. The proportion of Proteobacteria when the nitrite nitrogen decreased was lower than that when the ammonia nitrogen concentration decreased, while the proportions of the green bacteria, actinomycetes and planktomycetes increased.

(2) By designing three treatment groups with a cleaning frequency of 0.5 times/d, 1 time/d and 2 times/d, the effect of cleaning frequency on the water treatment of the biological filter was studied. The results showed that all three treatment groups could reduce ammonia nitrogen and nitrite nitrogen to a lower level, and there was no significant difference. However, the treatment group with a cleaning frequency of 2 times/d can significantly drain the suspended solids out of the system, and significantly reduces the nitrate nitrogen content in the system compared to the other two treatment groups. Nitrate nitrogen is the final product of nitrogen. The decrease in content indicates that the nitrogen content in the system is reduced, which reduces the water treatment load of the circulating water system. Therefore, the comprehensive cleaning frequency affects the nitrification performance and pollution interception capacity of the self-cleaning biological filter, and the cleaning frequency of the biological filter should be appropriately increased. Under the experimental conditions, the self-cleaning biological filter has a better self-cleaning frequency of 2 times/d.

(3) The water treatment capacity of different flow circulating water systems is different. When the flow is controlled at 1200 L/h and 1500 L/h, it is beneficial to maintain the contact time between microorganisms and the aquaculture water body. Therefore, the biological filter has better water treatment capacity and can Transform ammonia nitrogen and nitrite nitrogen into nitrate nitrogen that is not sensitive to aquaculture organisms in time, where the flow rate is 1200 L/h (113  cycles/h), and the removal of chemical oxygen demand is higher than the flow rate. 900 L/h (1 cycle volume/h), but there is no significant difference compared with 1500 L/h (123  cycle volume/h). Therefore, the effect is not significant when the flow rate reaches more than 1200 L/h, and it is a better flow parameter to control the flow rate at 1200 L/h.

(4) The filtering effect of a microfilter is related to the size of its mesh. The larger the mesh of the microfilter, the more particulate matter it can filter out and the stronger the water purification capacity. This experiment has a mesh size of 250 meshes. The filtration effect of the lower microfiltration machine is better than that of 120 mesh and 200 mesh. The 250 mesh microfiltration machine removes a large amount of solid particles, which reduces the content of particles carried by the aquaculture water into the biological filter, thereby significantly reducing the ammonia nitrogen and nitrous acid in the water. The concentration of salt nitrogen and chemical oxygen demand improves the water treatment capacity of the self-cleaning biological filter.

(5) The filling rate of the filler affects the water treatment capacity of the biological filter. S2 (75% filling rate) and S3 (100% filling rate) are thicker, which retains more particles, and can discharge more particles during self-cleaning. , So that the total suspended solids in the system is smaller than the S1 (50% filling rate) treatment group, the chemical oxygen demand concentration of the S1 treatment group is higher than the S2 and S3 treatment groups, and the difference between the S2 and S3 treatment groups is not obvious. The concentration of ammonia nitrogen and nitrite nitrogen in the S1 treatment group was significantly higher than that of S2 and S3, but the difference in the concentration of ammonia nitrogen and nitrite nitrogen in the S2 and S3 treatment groups was not significant. In combination with the above, selecting a filling rate of 75% is a better filling rate parameter.

The results of this experiment will promote the development of industrialized circulating aquaculture to conform to the needs of the development of the times, and also provide a theoretical basis for the formation of a more water-saving and efficient circulating water system.

摘 要. I

Abstract III

第一章 引言. 1

1.1 我国水产养殖业的发展现状. 1

1.2 工厂化循环水养殖系统. 1

1.2.1 循环水养殖系统的定义和特点. 1

1.2.2 海水养殖尾水的危害. 2

1.3 循环水养殖系统的水处理技术. 3

1.3.1 物理处理技术. 3

1.3.2 化学处理技术. 4

1.3.3 生物处理技术. 4

1.4 生物滤器工艺及其发展. 5

1.4.1 国外研究进展. 5

1.4.2 国内研究进展. 6

1.5 本课题的研究目的及内容. 7

1.5.1 研究目的及意义. 7

1.5.2 研究内容及预期目标. 8

1.5.3 技术路线. 8

第二章 自洁式生物滤器不同挂膜方法的过程影响研究. 9

2.1 材料与方法. 10

2.1.1 实验装置. 10

2.1.2 填料及其参数. 11

2.1.3 实验负载. 11

2.1.4 成熟生物膜的驯化培养. 11

2.1.5 实验方法及系统运转. 12

2.1.6 样品采集. 13

2.1.7 实验分析项目及分析方法. 13

2.2 结果与分析. 14

2.2.1 纤维球填料的挂膜. 14

2.2.2 氨氮、亚硝酸盐氮和硝酸盐氮浓度变化. 14

2.2.3 化学需氧量和总固体悬浮物浓度变化. 17

2.2.4 生物信息学. 20

2.3 讨论. 23

2.4 结论. 25

第三章 清洗频率对生物滤器水处理性能的影响. 26

3.1 材料与方法. 26

3.1.1 实验装置. 26

3.1.2 实验负载. 26

3.1.3 实验设计及系统运转. 26

3.1.4 实验分析项目及分析方法. 27

3.2 结果与分析. 27

3.2.1 清洗频率对生物滤器硝化性能的影响. 27

3.2.2 清洗频率对生物滤器截污能力的影响. 29

3.3 讨论. 31

3.3.1 清洗频率对生物滤器硝化性能的影响. 31

3.3.2 清洗频率对生物滤器截污能力的影响. 32

3.4 结论. 33

第四章 不同流量对生物滤器水处理性能影响. 34

4.1 材料与方法. 34

4.1.1 实验装置. 34

4.1.2 实验负载. 34

4.1.3 实验设计. 34

4.1.4 实验分析项目及分析方法. 34

4.2 结果与分析. 35

4.2.1 氨氮、亚硝酸盐氮和硝酸盐氮浓度变化. 35

4.2.2 化学需氧量浓度变化. 37

4.3 结论. 38

第五章 不同微滤机网目对生物滤器的影响研究. 39

5.1 材料与方法. 39

5.1.1 实验装置. 39

5.1.2 实验负载. 39

5.1.3 实验设计. 39

5.1.4 实验分析项目及分析方法. 39

5.2 结果与分析. 40

5.2.1 氨氮、亚硝酸盐氮和硝酸盐氮浓度变化. 40

5.2.2 化学需氧量和总固体悬浮物浓度变化. 42

5.3 结论. 46

第六章 填料填充率对自洁式生物滤器的水处理效果研究. 47

6.1 材料与方法. 47

6.1.1 实验装置. 47

6.1.2 实验负载. 47

6.1.3 实验设计. 47

6.1.4 实验分析项目及分析方法. 47

6.2 结果与分析. 48

6.2.1 氨氮、亚硝酸盐氮和硝酸盐氮浓度变化. 48

6.2.2 化学需氧量和总固体悬浮物浓度变化. 51

6.3 结论. 53

第七章 总结与问题. 54

7.1 结论. 54

7.2 问题. 55

7.3创新点. 55

参考文献. 56

致 谢. 62

硕士在读期间论文发表情况. 64