UV-C辐照对河水溶解有机质降解及微生物可利用性的影响  

Effect of UV-C Irradiation on Dissolved Organic Matter and Its Bioavailability

作　　者：马琼琳 李朋辉[1] 黄清辉[1] 

机构地区：[1]同济大学环境科学与工程学院,长江水环境教育部重点实验室,上海200092

出　　处：《环境科学研究》2014年第3期259-265,共7页Research of Environmental Sciences

基　　金：国家自然科学基金项目(41071301);中央高校科研基本业务费专项(0400219216)

摘　　要：从黄浦江及其上游支流采集表层水样，进行了微生物培养、UV—C辐照和微生物再培养等处理过程，测定水样P（DOC）（DOC为溶解有机碳）、紫外可见吸收光谱和荧光光谱，探讨河水DOM（溶解有机质）的光化学降解和微生物可利用性特征．结果表明：不同处理过程对DOM不同组分去除的贡献率不同，黄浦江河水经微生物培养后，P（DOC）和CDOM（有色溶解有机质）含量[以a335（335nm处的吸收系数）计]分别下降了5％～27％和5％左右，而FDOM（荧光溶解性有机质）含量（以最大荧光强度表示）稍有增加；继续经UV—C辐照24h后，P（DOC）和CDOM含量分别下降了7％～36％和79％～96％，而FDOM含量下降了95％以上，说明水体中大部分CDOM和FDOM可通过UV-C辐照去除，并且去除率显著高于微生物降解．UV—C辐照不仅可以降解DOM，而且可以改变DOM的微生物可利用性，其中一部分SLDOM（半活性溶解有机质）经UV—C辐照后能够再次被微生物利用，其中4％～28％的DOC和5％～14％的CDOM可再次被微生物降解．Laboratory batch experiments of bacterial cultures and ultraviolet-C （UV-C） irradiation were conducted using surface water samples collected from Huangpu River and its upper tributaries. Dissolved organic carbon （DOC） concentrations, UV-Visible absorption spectra and fluorescence spectra were measured to investigate the bioavailability and photodegradation of dissolved organic matter （ DOM）. The results showed that the removals of DOC, fluorescent dissolved organic matter （FDOM） and chromophoric dissolved organic matter （CDOM） varied with different treatments. Approximately 5% -27% of DOC and 5% of CDOM were consumed during the microbial growth progress. However, the FDOM intensity increased slightly. After 24-hour UV-C irradiation, further loss of DOC （7%-36% ） was much lower than those of CDOM （79%-96%） and FDOM （more than 95% ）. The removal rates of CDOM and FDOM during the UV-C irradiation were much higher than those during the microbial degradation. Besides, some SLDOM （ semiactive DOM） , which were difficult to be utilized by microorganisms, can be used once again. It indicated that UV-C irradiation can change the bioavailability of DOM. In this study, 4% -28% of DOC and 5% -14% of CDOM were further biodegraded after UV-C irradiation.

关 键 词：光化学降解 生物降解 溶解有机质 三维荧光光谱 紫外吸收光谱 

分 类 号：X131.2[环境科学与工程—环境科学]