亚热带河口陆基养虾塘水体CDOM三维荧光光谱平行因子分析

利用三维荧光光谱平行因子分析(EEMs-PARAFAC)技术,对我国亚热带地区闽江、木兰溪、九龙江河口滨海陆基养虾塘水体的有色溶解性有机质(CDOM)进行了组分及来源分析.研究表明从养虾塘水体CDOM荧光光谱中解析出4个有效PARAFAC荧光组分,包括2种类蛋白质物质和2种类腐殖酸物质,其中类蛋白质组分是河口陆基养虾塘水体中CDOM的主要组成部分.水体的荧光指数FI和自生源指标BIX表明河口区滨海陆基养虾塘水体中CDOM的强自生来源贡献.而腐殖化指标HIX表明养殖塘水体具有弱腐殖化特征.类蛋白质组分与类腐殖质组分之间可能具有相同的来源属性和地化行为,盐度与CDOM呈现极显著负相关,而DOC与CDOM中类腐殖质组分(C2、C3)呈现显著正相关.本研究为进一步揭示养虾塘水体CDOM的光化学性质提供了科学依据.

Parallel Factor Analysis of Fluorescence Excitation Emission Matrix Spectroscopy of CDOM from the Mid-culture Period of Shrimp Ponds in a Subtropical Estuary

Components of chromophoric dissolved organic matter (CDOM) from eight coastal land-based shrimp ponds in the Minjiang, Mulan, and Jiulong rivers of subtropical southeastern China were determined by fluorescence excitation emission matrix spectroscopy combined with parallel factor analysis (EEMs-PARAFAC). Four separate fluorescence components, including two protein-like components (C1, C4) and two humic-like components (C2, C3), were identified as the dominant components of the CDOM in these shrimp ponds. The fluorescence indices (FI, BIX, and HIX) suggest that the CDOM of shrimp ponds shows low humification and is mainly derived from spontaneous sources. The protein-like and humic-like components have similar sources and exhibit a similar geochemical behavior. The salinity is negatively correlated with all CDOM fractions, whereas the DOC concentrations show only a positive correlation with the humic fractions of the CDOM. This study provides a scientific basis for the photochemical properties of CDOM in shrimp ponds.