Iara Brandão de Oliveira

Inorganic and organic contaminants in drinking water stored in polyethylene cisterns

This work evaluated the presence of contaminants in stored rainwater in 36 polyethylene tanks installed in two rural communities of the semiarid of Bahia, Brazil. Carbonyl compounds were analyzed by High Performance Liquid Chromatography (HPLC-UV), BTEX (Benzene, Toluene, Ethylbenzene and Xylenes) by gas chromatoghaphy (GC-FID), and trace elements by inductively coupled plasma optical emission spectrometry (ICP-OES). Seven carbonyl compounds were quantified including acrolein (<3-115 µg L-1), which is considered a potent mutagenic agent, above the potability limit in 75% of the cases. Trace elements such as copper, zinc, barium, aluminum and lead, more frequently found, were also quantified, and lead (<0,56-99 µg L-1) was above the tolerable limit for drinking water of 10 μg L-1 in 73% of the cases. The results show that the stored water in polyethylene cisterns in the Brazilian semiarid region does not present satisfactory conditions for human consumption.

UVR and PAR absorbing compounds of marine brown macroalgae along a latitudinal gradient of the Brazilian coast

Absorption spectra are indicative of biological sample chemical composition and can be used as a basis for the construction of descriptive and predictive models for biotechnological screening or assays. In marine algae, chemical composition can vary due to species-specific differences in biochemistry, as well as intra-specific responses to unique environmental variables. Different indices (UVCi, UVB+Ai and PARi) were proposed and calculated to evaluate how photoprotective compounds vary in 18 species of Phaeophyceae. In addition, they were correlated to abiotic factors. Through this technique, seven main peaks were detected in the absorbing spectra of marine brown algal extracts. The highest photoprotective indices values were found in species collected in tropical areas, where higher solar radiation is observed compared to the southern Brazilian coast. Considering additional abiotic factors, water temperature and nitrate concentration were negatively correlated with UV indices. PARis indices were positively affected by nitrate. All species collected on the Brazilian coast have absorption peaks in the region of phenolic compounds and carotenoids, suggesting that tropical marine brown macroalgae may have developed an effective antioxidant defense system, suggesting adaptation to environments characterized by high solar radiation. UVR/PAR indices congregated essential information to possible future biotechnological screening, facilitating selection of high priority species or sites, fostering actions to enhance alternative sustainable management strategies of coastal environments.

Application of the index WQI-CCME with data aggregation per monitoring campaign and per section of the river: case study—Joanes River, Brazil

This work applied the Water Quality Index developed by the Canadian Council of Ministers of the Environment (WQI-CCME), to communicate the water quality per section of the Joanes River basin, State of Bahia, Brazil. WQI-CCME is a statistical procedure that originally requires the execution of at least four monitoring campaigns per monitoring location and the measurement of at least four parameters. This paper presents a new aggregation method to calculate the WQI-CCME because, to apply the original method in Joanes River, a huge loss of information would occur, by the fact that, the number of analyzed parameters varied between the monitoring campaigns developed by the Government Monitoring Program. This work modified the original aggregation method replacing it by a data aggregation for a single monitoring campaign, in a minimum of four monitoring locations per section of the river and a minimum of four parameters per monitoring location. Comparison between the calculation of WQI-CCME for river sections, with the index, WQI-CETESB, developed by the Brazilian Environmental Sanitation and Technology Company—CETESB, proved the applicability of the new aggregation method. The WQI-CETESB has it bases on the WQI from the National Sanitation Foundation and uses nine fixed parameters. As WQI-CCME uses the totality of the analyzed parameters without restrictions, it is more flexible, and the results seem more adequate to indicate the real river water quality. However, the WQI-CCME has a more stringent water quality scale in comparison with the WQI-CETESB, resulting in inferior water quality information. In conclusion, the WQI-CCME with a new aggregation method is adequate for communicating the water quality at a given time, per section of a river, respecting the minimum number of four analyses and four monitoring points. As a result, without a need to wait for other campaigns, it reduces the cost of a monitoring program and the period to communicate the water quality. The adequacy of the WQI-CCME was similar to the finding of others.