Correlation of Dissolved Organic Matter Fluorescence and Several Metals Concentration in a Freshwater System

AbstractDissolved organic matter (DOM) strongly influences several ecosystem processes, including the reduction of solar radiation, control of nutrient availability, modification of contaminant toxicity, and energy cycling. Using fluorescence spectroscopy, one of the most important DOM features, metal binding affinity, has been characterized, due to its direct effect on aquatic ecosystems. This paper presents the analysis of the relationship between type and concentration of metal ions and DOM fluorescence for water sampled from Arges River. The results suggest that certain competitive complexation processes occur among metal ions and that iron and chromium ions have the most significant impact on DOM fluorescence

ASSESSMENT OF URBAN DEVELOPMENT IMPACT ON LIMNOLOGICAL SYSTEMS

The aim of this study is to evaluate the human impact, in terms of organic matter distribution and chlorophyll found in representative lakes from Bucharest city. The water quality of these lakes was evaluated using fluorescence spectroscopy together with conductivity and pH. Fluorescence data, in the form tryptophan/humic acid ratio, was used to evaluate the humification degree and to evidence the level of microbial contaminations of water lakes. Graphical representation of fluorescence ratio, Chl-a intensity, conductivity and pH was used to divide the analyzed samples in two groups. A quality score of 0 or 1 was introduced to delimitate between good or poor water quality using threshold values. The use of quality scores was helpful in realisation of a water quality map with Bucharest’s lakes, indicating the limnological systems’ ecological state. The results showed that the analysis of chromophoric organic matter can be useful in identifying the negative human influence on urban lakes

Evaluation of lentic ecosystems from Bucharest City

Abstract: Bucharest is the capital city and also one of the largest cities in Romania. It disposes of natural and artificial lakes, arranged for different leisure activities and some of them even for bathing. Monitoring and maintaining the quality of lentic ecosystems is important from both an economical and environmental point of view. Several lake water samples were collected from Bucharest city area. The water quality of these lakes was evaluated using, for the first time, fluorescence spectroscopy together with standard indicators (conductivity and pH, oxygen indicators, like dissolved oxygen -DO and chemical oxygen demand -COD and nutrients, specifically nitrates and nitrites). The anthropic influence on the lentic ecosystems was evidenced by the presence of high quantities of ammonia, a clear sign of uncontrolled wastewater spills from the residential settlements on the lake borders. From the fluorescence measurements, various indices were calculated as ratio between regions of the fluorescence maps. A good correlation was found between some of these indices and the standard parameters, thus suggesting that fluorescence spectroscopy might be a potential tool in the monitoring of the lake water quality