一种鸡粪来源溶解有机氮在天然海水中不同降解阶段生物可利用性及其组分结构特征  

BIOAVAILABILITY AND COMPONENT STRUCTURE OF DISSOLVED ORGANIC NITROGEN FROM CHICKEN MANURE AT DIFFERENT DEGRADATION STAGES IN NATURAL SEAWATER

作　　者：曾翠 李克强[1] 张现盛 赵婧[1] 所芳屹 王修林[1] ZENG Cui;LI Ke-Qiang;ZHANG Xian-Sheng;ZHAO Jing;SUO Fang-Yi;WANG Xiu-Lin(Key Laboratory of Marine Chemistry Theory and Engineering Technology,Ministry of Education,OceanUniversity of China,Qingdao 266100,China)

机构地区：[1]中国海洋大学海洋化学理论与工程技术教育部重点实验室,化学化工学院,山东青岛266100

出　　处：《海洋与湖沼》2024年第3期675-690,共16页Oceanologia Et Limnologia Sinica

基　　金：国家自然科学基金,42130403号,42076221号;山东省重点海域富营养化监测评估,SDHY2022-014号,SDHY2023-022号。

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、芳基和羧基/酯基等官能团;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、芳基和羧基/酯基等。RDON较BDON在芳香性、疏水性和腐殖化指数上均显著升高,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。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.However,it is difficult to characterize the constantly changing bioavailability and structure of DON during natural seawater aging.By focusing on a type of DON derived from chicken manure,a year-long natural seawater degradation experiment was performed to measure and characterize the physicochemical parameters and spectral features of DON across various degradation stages.Results show that of the total bioavailable DON(BDON)by culture time,the labile bioavailable DON(LBDON,0~12 days),half-labile bioavailable DON(HLBDON,12~80 days),and refractory bioavailable DON(RBDON,80~365 days)fractions occupied 51.41%,31.79%,and 2.63%,respectively.Notably,LBDON and HLBDON were mainly composed of three-dimensional fluorescent tryptophan T component and soil fulvic acid D component,and amine functional groups were the main components in structure.In contrast,RBDON was mainly composed of visible light fulvic acid C1 component,including amine,hydroxyl,aromatic,and carboxyl/ester functional groups.The refractory DON(RDON)consisted of mainly three-dimensional fluorescent ultraviolet region fulvic acid A component and humic acid like E component,including alkyne,aromatic ring,and carboxyl/ester groups in structure.Compared to BDON,RDON showed significant increases in aromaticity by 89.8%,hydrophobicity by 86.5%,and humification by 39.2%.This study contributed to a better understanding of the bioavailability and ecological impacts of terrestrial DON in the ocean.

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 

分 类 号：P734[天文地球—海洋化学]