Evaluation of surface water quality using an ecotoxicological approach: a case study of the Piracicaba River (São Paulo, Brazil)

A long-term study was conducted to evaluate Piracicaba River water (São Paulo state, Brazil) using different methodologies and organisms. During 1 year (February 2011 to January 2012), water samples were collected monthly at six different locations and exposed under laboratory conditions to the microcrustaceans Ceriodaphnia dubia and Ceriodaphnia silvestrii for 7 days and to the fish Danio rerio for 4 days to evaluate effects on reproduction and on gill morphology, respectively. Physical–chemical parameters of the water were also measured. Physical–chemical characteristics demonstrated decreasing water quality from upstream to downstream of the river. Effects on the reproduction of C. dubia and C. silvestrii were observed in 3 months (February and March 2011 and January 2012) and occurred in samples collected close to industrialized cities like Americana and Piracicaba. Evaluation of the gills showed normal function of the organ during all months, except in February, September, and October for some locations.     

Petroleum Hydrocarbons Rhizodegradation by Sebastiania commersoniana (Baill.) L. B. SM. & Downs

Petroliferous activities in Brazil have an accelerated development in the last years. As a consequence, the incidence of environmental accidents such as oil spills and contamination of soils has increased significantly. Therefore, it is extremely necessary to develop remediation techniques with lower costs, decontamination efficiency and impact minimisation. The aim of this work was to evaluate Sebastiania commersoniana phytoremediation potential in soil contaminated by petroleum. This species, which is a native tree, was selected due to its proven capacity for surviving in areas contaminated by petroleum. Experiments were carried out with soils that were vegetated but non-contaminated, soils that were freshly contaminated (25, 50 and 75 g kg^?1) but non-vegetated, and soils that were vegetated and contaminated, samples were collected 60 and 424 days after contamination with the purpose of evaluating the percentage of petroleum degradation in relation to the time. The results obtained in the present study allow us to state that S. commersoniana proves to be tolerant to petroleum contamination with respect to plant’s growth. The degradation of petroleum hydrocarbons was evaluated by gas chromatography with a flame ionisation detector (GC-FID) equipped with a capillary column HP-5 (5% phenyl-methylpolysiloxane, 30 m; 0.25 mm; 0.25 μm). According to chromatographic analysis, samples in contact with S. commersoniana showed a significant area reduction of the hydrocarbon peaks. Analysis of the 60-day samples showed a reduction of petroleum hydrocarbons area higher than 60% and the 424-day samples showed a reduction higher than 94%, which demonstrates that a petroleum degradation process is occurring.     

Acute toxicity of sugarcane vinasse to aquatic organisms before and after pH adjustment

The purpose of this study was to investigate the toxicity of vinasse to cladocerans and fish before and after pH adjustment using an acute toxicity test. Linear and quadratic regression models were adjusted to demonstrate the concentration–response relationship between vinasse and the endpoints evaluated. The median lethal concentrations (LC_50–48h) of vinasse before pH adjustment for Ceriodaphnia dubia and Daphnia magna were 0.67% and 0.80% respectively, and the median lethal concentrations (LC_50–96h) for Danio rerio was 2.62%. After pH adjustment, the values increased for all organisms, demonstrating a decrease in toxicity. This study reported marked toxicity for vinasse to aquatic organisms with toxicity reduction after pH adjustment.     

Effects of oil contamination on plant growth and development: a review

Environmental Science and Pollution Research - Oil spills generate several environmental impacts and have become more common with the increase in petroleum extraction, refining, transportation, and...