水力负荷对内循环生物脱氮装置脱氮效能影响及其机理  

Effect of hydraulic loading rate on nitrogen removal efficiency andmechanism of an internal circulation biological nitrogen removal device

作　　者：郑毅凯 李甍[1] 孙佐梁 宋协法[1] 李贤 董登攀[1] ZHENG Yikai;LI Meng;SUN Zuoliang;SONG Xiefa;LI Xian;DONG Dengpan(Ocean University of China,Hydro-Environmental Engineering Laboratory,Qingdao,Shandong 266003,China)

机构地区：[1]中国海洋大学水产学院,海洋生物水环境工程重点实验室,山东青岛266003

出　　处：《渔业现代化》2024年第4期82-94,共13页Fishery Modernization

基　　金：国家重点研究发展计划项目(2023YFD2400404);山东省科技型中小企业创新能力提升工程项目(2023TSGC0925)。

摘　　要：循环水养殖系统(Recirculating Aquaculture Systems,RAS)中高溶氧浓度、低碳氮比等特点限制生物滤池反硝化性能,造成NO_(3)^(-)-N累积,危害养殖动物健康,给水产养殖尾水达标排放带来挑战。本研究使用内循环生物脱氮装置对海水循环水养殖尾水进行处理,探究了水力负荷(HLR)分别为1、2和3 m^(3)/(m^(2)·d)条件下装置中水质指标的变化情况,并在每阶段试验结束后取PCL和K3填料样本进行高通量测序,对其微生物群落特征及功能基因预测结果进行统计分析。结果显示:装置稳定运行期间,HLR为2 m^(3)/(m^(2)·d)时,NO_(3)^(-)-N平均去除率最高,为67.31%±3.03%;NO_(3)^(-)-N去除负荷随HLR的升高而上升,在HLR为3 m^(3)/(m^(2)·d)时,达55.38±6.13 g·N/(m^(3)·d)。门水平上,PCL样本与K3样本中的优势菌群均为变形菌门(Proteobacteria);属水平上,具有反硝化功能的红杆菌科未知属( unclassified_f__Rhodobacteraceae )和鲁杰氏菌属( Ruegeria )在PCL填料与K3填料生物膜中均占据主导,这2种微生物为影响装置脱氮效能的关键属水平微生物。功能基因预测结果表明,当HLR升高时,参与反硝化作用的硝酸盐还原酶(EC 1.7.99.4)、亚硝酸盐还原酶(EC 1.7.2.1)、一氧化氮还原酶(EC 1.7.2.5)和一氧化二氮还原酶(EC 1.7.2.4)的丰度升高。研究表明,生物脱氮装置可将HLR定为2 m^(3)/(m^(2)·d),并在装置中定植、培养红杆菌科未知属和鲁杰氏菌属这2种细菌。该研究成果可为实际生产中生物脱氮装置HLR的设计提供参考,为相关脱氮效能的研究提供新思路。In Recirculating Aquaculture Systems (RAS),nitrifying bacteria in biofilters are responsible for converting toxic substances such as organic nitrogen,NH + 4-N,and NO-2-N in the culture water into less toxic NO_(3)^(-)-N.However,the high dissolved oxygen concentration and low carbon-to-nitrogen ratio in the system limit the denitrification performance of the biofilters,leading to the accumulation of NO_(3)^(-)-N.This accumulation not only poses a threat to the health of cultured animals but also presents challenges for the compliant discharge of aquaculture tailwater.This study employs an internal recirculating biological denitrification device to treat marine RAS wastewater and investigates water quality changes under different Hydraulic Loading Rate (HLR) conditions,specifically setting HLR at 1 m^(3)/(m^(2)·d),2 m^(3)/(m^(2)·d),and 3 m^(3)/(m^(2)·d).At the end of each experimental stage,samples of PCL and K3 fillers from the device were collected for high-throughput sequencing to analyze the characteristics of their microbial communities and the results of functional gene predictions.The results indicate that during stable operation of the device,the average removal rate of NO_(3)^(-)-N was highest at 67.31%±3.03% when the HLR was 2 m^(3)/(m^(2)·d).The removal load of NO_(3)^(-)-N increased with the rise of HLR,reaching 55.38±6.13 g·N/(m^(3)·d) at an HLR of 3 m^(3)/(m^(2)·d).During the stable operation of the device,no accumulation of NH + 4-N,NO-2-N,and COD was detected in the effluent,with the main denitrification area located in the inner circle of the device.At the phylum level,Proteobacteria was the dominant bacterial phylum in both PCL and K3 samples.At the genus level,the denitrifying unclassified_f__Rhodobacteraceae and Ruegeria dominated the biofilms on both types of fillers.The abundance of unclassified_f__Rhodobacteraceae in the PCL samples increased with the increase in HLR,whereas the abundance of Ruegeria increased as the HLR decreased.Functional gene prediction results indicated that the

关 键 词：水力负荷 生物脱氮装置 反硝化 微生物群落 循环水养殖 聚己内酯 

分 类 号：S969.38[农业科学—水产养殖]