Arguelho Maria de Lara Palmeira de Macedo, Alves José do Patrocínio Hora, Monteiro Adnívia Santos Costa, Garcia Carlos Alexandre Borges
Department of Chemistry, Federal University of Sergipe, São Cristóvão, SE, 49100-000, Brazil.
Environ Monit Assess. 2017 Jun;189(6):272. doi: 10.1007/s10661-017-5966-7. Epub 2017 May 17.
The Sal River estuary, which is located in the state of Sergipe, Northeastern Brazil, stands out as an urban estuary, anthropogenically impacted by untreated and treated wastewater discharge. Synchronous fluorescence spectroscopy and measurement of dissolved organic carbon (DOC) were used for characterization of dissolved organic matter (DOM) in the estuarine water. Dissolved organic carbon concentrations ranged from 7.5 to 19.0 mg L and, in general, the highest values were recorded during dry season. For both seasons (dry and rainy), DOC presented an inverse linear relationship with salinity, which indicates a conservative dilution of organic matter coming into the estuary. During rainy season, anthropogenic organic constituents and humic substances from land-based sources predominated in DOM composition, carried by river flow. Whereas during the dry season, it has been observed a significant increase of products generated by microbial degradation of anthropogenic organic matter. The relationships between fluorescence intensity and salinity suggest a conservative behavior during rainy season and a non-conservative behavior during dry season, with addition of fluorescent organic matter into the intermediate zone of the estuary. Photodegradation by action of sunlight caused a decrease in fluorescence intensity of humic and tryptophan-like constituents and the release of photoproducts, resulting in an increase in fluorescence intensity of protein-like constituents.
萨尔河河口位于巴西东北部的塞尔希培州，是一个受未经处理和经处理的废水排放人为影响的城市河口。同步荧光光谱法和溶解有机碳（DOC）测量被用于表征河口水中的溶解有机物（DOM）。溶解有机碳浓度范围为7.5至19.0毫克/升，一般来说，最高值出现在旱季。在旱季和雨季这两个季节，DOC与盐度均呈反线性关系，这表明进入河口的有机物存在保守性稀释。在雨季，陆源的人为有机成分和腐殖物质在DOM组成中占主导地位，由河流径流携带。而在旱季，观察到人为有机物微生物降解产生的产物显著增加。荧光强度与盐度之间的关系表明，雨季时呈现保守行为，旱季时呈现非保守行为，且有荧光有机物进入河口的中间区域。阳光作用下的光降解导致腐殖和类色氨酸成分的荧光强度降低以及光产物的释放，从而使类蛋白质成分的荧光强度增加。
