中文关键词蓝藻胞内有机质(I-DOM)生物降解三维荧光-平行因子分析法(EEM-PARAFAC)太湖 英文关键词cyanobacteriaintracellular-dissolved organic matter (I-DOM)biodegradationthree-dimensional fluorescence matrix-parallel factor (EEM-PARAFAC)Lake Taihu

作者	单位	E-mail
张巧颖	中国科学院南京地理与湖泊研究所, 湖泊与环境国家重点实验室, 南京 210008 中国科学院大学, 北京 100049	15806033905@163.com
孙伟	中国科学院南京地理与湖泊研究所, 湖泊与环境国家重点实验室, 南京 210008 江苏省太仓市璜泾镇人民政府, 太仓 215427
杜瑛珣	中国科学院南京地理与湖泊研究所, 湖泊与环境国家重点实验室, 南京 210008	yxdu@niglas.ac.cn
巩小丽	中国科学院南京地理与湖泊研究所, 湖泊与环境国家重点实验室, 南京 210008 南京万德斯环保科技股份有限公司, 南京 211100

中文摘要 蓝藻水华消亡时，藻细胞裂解会产生大量的胞内溶解性有机质（I-DOM）.本研究利用紫外-可见吸收光谱（UV-Vis）和三维荧光-平行因子分析法（EEM-PARAFAC），考察太湖蓝藻I-DOM在微生物降解过程的组成变化，并研究了温度（20、25和30℃）和I-DOM初始浓度（5、10和20 mg·L^-1）对I-DOM生物降解的影响.结果表明，I-DOM能较好被微生物降解，14 d后，DOC的去除率为50%~74%.初始I-DOM主要包含类色氨酸组分C1（80%），存在C2（一种广泛存在的类腐殖质，16.0%）和C3（微生物来源类腐殖质，3.7%）；几乎不含C4（微生物来源类腐殖质，0.3%）.微生物降解过程，这些组分既被消耗，同时又能被产生，呈现以下变化趋势：C1组分减少；C2组分变化趋势复杂，其先下降后增加，随后又下降；C3和C4先增加后减少.S_r、E₂：E₃和HIX指标的变化显示，降解过程中，溶液中DOM分子量增大，腐殖性增强.本实验条件的温度和I-DOM初始浓度范围均不改变各组分的变化趋势；3个温度中25℃条件下降解效果最佳；而随着I-DOM初始浓度的增加，I-DOM降解增强.结合笔者关于I-DOM光降解的研究，推断太湖水华消亡产生的DOM可能有以下的归趋：其中类色氨酸能被有效降解，而各类腐殖质难以完全降解；这些类腐殖质芳香性较强，极可能与金属物质发生作用而从水体中去除，被埋藏在沉积物中.本研究有助于探明太湖蓝藻水华消亡产生DOM的归趋. 英文摘要 A large amount of intracellular dissolved organic matter (I-DOM) is released during the senescent phase of phytoplankton cultures. This research investigated the bio-incubation of I-DOM of cyanobacteria in Lake Taihu under various temperatures (20, 25, and 30℃) and I-DOM initial concentrations (5, 10, and 20 mg·L^-1) with the aid of ultraviolet-visible spectroscopy (UV-Vis) and three-dimensional fluorescence matrix-parallel factor (EEM-PARAFAC). I-DOM was effectively degraded during the incubation. After 14 days, the DOC removal ratio was 50% ~74%. A tryptophan-like component (C1), a ubiquitous humic-like component (C2), and two microbially-derived humic-like components (C3 and C4) contributed 80.0%, 16.0%, 3.7%, and 0.3% to the initial I-DOM, respectively. During the bio-degradation, these components are not only consumed but also produced. C1 decreased during the incubation, while C3 and C4 increased at the beginning of biodegradation and then decreased. The change trend of C2 was complicated, i.e., it decreased firstly and then increased, but decreased again after 7 days. The changes in the optical indices of S_r, E₂:E₃ and HIX revealed that the molecular weight of DOM increased, and the aromaticity was enhanced during degradation. The reaction temperature and the initial concentration of I-DOM did not change the trend of the PARAFAC components. The temperature of 25℃ was the most suitable for I-DOM bio-degradation. Additionally, the degradation of I-DOM was enhanced with the increase in the initial concentration of I-DOM. Combined with our study on the photodegradation of I-DOM, the possible fate of I-DOM in Lake Taihu was proposed. The tryptophan-like compound could be effectively degraded, while the humic-like components could not be degraded completely. These humic-like components would potentially settle through adsorption or coprecipitation with metal substances. These results are helpful to understand the fate of I-DOM released by a cyanobacteria bloom in Lake Taihu.

PDF全文下载地址:

https://www.hjkx.ac.cn/hjkx/ch/reader/create_pdf.aspx?file_no=20210429&flag=1&journal_id=hjkx&year_id=2021