太湖蓝藻水华期可溶有机物的生物降解  

Biodegradation of dissolved organic matter in Lake Taihu during cyanobacterial blooms

作　　者：许明[1] 刘伟京[1] 白永刚[1] 涂勇[1] XU Ming;LIU Wei-jing;BAI Yong-gang;TU Yong(Jiangsu Key Laboratory of Environmental Engineering,Jiangsu Provincial Academy of Environmental Science,Nanjing 210036,China)

机构地区：[1]江苏省环境科学研究院,江苏省环境工程重点实验室,江苏南京210036

出　　处：《中国环境科学》2018年第9期3494-3501,共8页China Environmental Science

基　　金：江苏省科技厅社会发展-面上项目(BE2017765);南京市科技计划项目(201716004)。

摘　　要：以太湖蓝藻水华期产生的可溶有机物(DOM)为代表,研究溶解性有机碳(DOC)、有色DOM(CDOM)以及荧光DOM(FDOM)的生物降解,并结合平行因子分析和二维相关图谱分析(2D–COS)揭示独立FDOM组分的变化特征.结果表明,降解初期DOC浓度剧烈下降,而后缓慢降低,且与CDOM浓度线性相关.G模型拟合确定DOC中活性、半活性以及非活性部分分别占40%,37%,23%,表明藻华期DOC中大部分(77%)可在短期内降解.SUVA_(254)、S_R、HIX等指标变化说明生物降解中DOM的芳香度、平均分子质量、腐殖度等逐渐升高.4个独立FDOM组分的生物活性大小为:类色氨酸组分>类酪氨酸组分>类富里酸组分>类腐殖酸组分,其中类色氨酸和类酪氨酸是活性和半活性FDOM的主要组成,而类富里酸和类腐殖酸组分是非活性FDOM的主要组成.结合2D–COS进一步发现激发波长较低的荧光组分优先被微生物降解.Occurrence of cyanobacterial blooms can induce considerable patchiness in the quantity and quality of dissolved organic matter(DOM).The present study investigated the changes of dissolved organic carbon(DOC),chromophoric DOM(CDOM)and fluorescent DOM(FDOM)in an inoculated 32-day laboratory incubation.The biodegradation of individual FDOM components was further studied using parallel factor analysis(PARAFAC)and two dimension correlation spectroscopy(2D-COS).The results showed that the DOC concentration decreased significantly initially,followed by a slow biodegradation.Fitting by G model successfully separated the DOC into labile(40%),semi-labile(37%)and refractory(23%)pools,suggesting that 77%of the DOC can be metabolized quickly after its production.The values of SUVA254,spectral slope ratio,and HIX indicated that the aromaticity,molecular weight,and humic degree of DOM increased with biodegradation.The bioavailability of 4PARAFAC components followed the order of:tyrosine->tryptophan->fulvic acid->humic acid-like component.Tyrosine-and tryptophan-like component accounted for a large proportion of the labile and semi-labile DOM,while the refractory DOM was mainly composed of fulvic-acidand humic acid-like component.Synchronous fluorescence spectra combined with 2D-COS revealed that the fluorescent compounds with lower excitation wavelengths were preferentially biodegraded.

关 键 词：蓝藻水华 可溶性有机质 生物降解 三维荧光光谱 二维相关分析 

分 类 号：X524[环境科学与工程—环境工程]