| 摘要: |
| 陆源溶解有机氮(DON)是近海环境中的重要氮来源,对海洋生态系统的影响与自身生物可利用性、组分和结构有关。如何表征DON在天然海水老化过程中不断变化的生物可利用性及其结构特征是难点。以畜禽养殖鸡粪作为DON来源,通过1年的天然海水自然降解实验,测定和表征了不同降解阶段DON的理化参数和光谱特征。结果表明,按培养时间划分的生物可利用组分(BDON)中,易利用组分(LBDON,0-12 d)、半易利用组分(HLBDON,12-80 d)和难利用组分(RBDON,80-365 d)占比分别为51.41%、31.79%和2.63%。其中,LBDON和HLBDON主要是三维荧光色氨酸T组分和土壤富里酸D组分,结构上主要是胺基官能团；RBDON主要是可见光富里酸C1组分,主要包括胺基、羟基、稀基和羧基等官能团；而惰性组分(RDON)主要是三维荧光紫外区富里酸A组分和类腐殖酸E组分,结构上主要包括炔基、芳环和羧基等。RDON较BDON在芳香性(SUVA254)、疏水性(SUVA260)和腐殖化指数(HIX)上均显著升高,分别升高了89.8%、86.5%和39.2%。研究结果有助于深入理解海洋中陆源DON的生物可利用性及其生态效应。 |
| 关键词: 溶解有机氮(DON) 生物可利用性 组分结构特征 陆源 莱州湾 |
| DOI：10.11693/hyhz20231200265 |
| 分类号: |
| 基金项目:国家自然科学基金项目（面上项目，重点项目，重大项目） |
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| BIOAVAILABILITY AND COMPONENT STRUCTURE CHARACTERISTICS OF DON, A CHICKEN MANURE SOURCE, AT DIFFERENT DEGRADATION STAGES IN NATURAL SEAWATER |
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ZENG Cui, LI Ke-Qiang, ZHANG Xian-Sheng, ZHAO Jing, SUO Fang-Yi, WANG Xiu-Lin
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Key Laboratory of Marine Chemistry Theory and Engineering Technology,Ministry of Education,OceanUniversity of China
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| Abstract: |
| Terrestrial dissolved organic nitrogen (DON) is an important nitrogen source in nearshore environments, and its impact on marine ecosystems is related to its inherent bioavailability, composition, and structure. It is difficult to characterize DON"s constantly changing bioavailability and structural characteristics during natural seawater aging. This study focuses on a type of DON derived from chicken manure, employing a year-long natural seawater degradation experiment to measure and characterize the physicochemical parameters and spectral features of DON across various degradation stages.The results showed that among the bioavailable components (BDON) divided by cultivation time, the proportions of easily available components (LBDON, 0-12 days), semi-available components (HLBDON, 12-80 days), and refractory components (RBDON, 80-365 days) are 51.41%, 31.79%, and 2.63%, respectively. Notably, LBDON and HLBDON are mainly composed of three-dimensional fluorescent tryptophan T component and soil fulvic acid D component, with amine functional groups as the main structural components. In contrast, RBDON is mainly composed of visible light fulvic acid C1 component, which mainly includes functional groups such as amino, hydroxyl, dilute, and carboxyl groups. The inert components (RDON) mainly consist of three-dimensional fluorescent ultraviolet region fulvic acid A component and humic acid like E component, structurally including alkyne, aromatic ring, and carboxyl groups. RDON showed significant increases in aromaticity (SUVA254), hydrophobicity (SUVA260), and humification index (HIX) compared to BDON, with increases of 89.8%, 86.5%, and 39.2%, respectively. These research outcomes contribute to a more profound understanding of the bioavailability and ecological impacts of terrestrial DON in the ocean. |
| Key words: dissolved organic nitrogen (DON) bioavailability component structure characteristics land source Laizhou Bay |