长江口不同来源溶解有机质光化学/微生物降解作用及机制研究  

Photochemical/Microbial Degradation of Dissolved Organic Matter from Different Sources in Changjiang Estuary

作　　者：王新科 金红 梁生康[1,2] 马浩阳 郭金强 李姗姗 吕浩然 WANG Xin-Ke;JIN Hong;LIANG Sheng-Kang;MA Hao-Yang;GUO Jing-Qiang;LI Shan-Shan;LV Hao-Ran(College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China;The Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China;Qingdao Ecological Environment Monitoring Center of Shandong Province, Qingdao 266003, China)

机构地区：[1]中国海洋大学化学化工学院,山东青岛266100 [2]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,山东青岛266100 [3]山东省青岛生态环境监测中心,山东青岛266003

出　　处：《中国海洋大学学报（自然科学版）》2020年第12期88-97,共10页Periodical of Ocean University of China

基　　金：国家重点研究发展计划项目(2018YFC1407600);中央高校基本科研业务费专项项目(201962011)资助。

摘　　要：本论文应用船基受控培养试验,考察了长江口陆源、海源和混合源溶解有机质(DOM)的光降解、微生物降解、光-微生物同时以及光-微生物依次降解作用,测定培养过程中溶解有机碳(DOC)及其组分总溶解态氨基酸(TDAA)和有色溶解有机质(CDOM)光学特征参数的动态变化,解析不同来源DOM光化学/微生物降解作用机制。结果表明,不同来源DOM对光化学降解和微生物降解的敏感性不同。陆源DOM易被光降解,在12 d的培养周期中,约70%的CDOM被移除。海源DOM易被微生物降解,DOM中TDAA先于其他组分被降解,导致TDAA在DOC中的丰度(TDAA(%DOC))显著降低。混合源DOM的光化学降解和微生物降解作用都较为明显。光-微生物同时作用体系中,光化学降解和微生物降解具有拮抗作用,这是由于紫外辐射及光活性自由基等抑制了微生物生长。光降解然后微生物作用,可协同降解陆源DOM,这是由于光化学作用可将大分子转化成易被微生物利用的小分子物质,DOM的微生物可利用性增大。The ship-based controlled incubation experiment was conducted to investigate the photodegradation,microbial degradation,synchronous and sequential system of photo-and microbial degradation of terrestrial,mixed and marine dissolved organic matter(DOM)in Changjiang estuary.To analyze the photochemical/microbial degradation mechanism of different sources DOM,the dynamic variations of dissolved organic carbon(DOC),total dissolved amino acid(TDAA)and optical characteristic properties of colored dissolved organic matter(CDOM)during incubation experiments were followed.The results showed that DOM from different sources had diverse sensitivities to photochemical and microbial degradation.Terrestrial DOM is vulnerable to photodegradation.During 12 days of incubation experiment,about 70%of CDOM was removed.Marine DOM is easy to be degraded by microorganisms.TDAA were preferentially removed from marine DOM components,resulting in a significant decrease in proportion of TDAA in DOC(TDAA(%DOC)).The photochemical and microbial transformation and degradation of DOM from mixed source were obvious,due to its terrestrial and marine blended characteristics.Owing to the inhibition of microorganisms by ultraviolet radiation and photoactive radicals,there was an antagonistic effect between photochemical and microbial degradation in the synchronous photo-and microbial degradation system.Terrestrial DOM photo-alteration had a positive effect on microbial degradation in sequential system of photo-and microbial degradation.Large molecular organic matter was transformed into high bioavailability small molecular substances by photochemical process,resluting in the elevated bioavailability of DOM.

关 键 词：溶解有机质 光化学降解 微生物降解 陆源 海源 

分 类 号：P734.43[天文地球—海洋化学]