Icaro T. A. Moreira

Phytoremediation in mangrove sediments impacted by persistent total petroleum hydrocarbons (TPH’s) using Avicennia schaueriana

This study evaluated the efficiency of Avicennia schaueriana in the implementation of phytoremediation compared with intrinsic bioremediation in mangrove sediments contaminated by total petroleum hydrocarbons (TPHs). The experiment was conducted for 3months at a pilot scale under conditions similar to a mangrove: the dynamics of the tides were simulated, and physical, chemical, microbiological and biogeochemical parameters were monitored. After the 90 days, it was found that the phytoremediation was more efficient in the degradation of the TPHs compared to bioremediation, reducing the initial concentration of 32.2-4.2 mg/g. A. schaueriana was also more efficient in mediating the degradation of different fractions of hydrocarbons, achieving a removal efficiency of 87%. The microbiological results consisted of a higher growth in the model with the plants, demonstrating the phytostimulation ability of the plants. Finally, the experiment showed that phytoremediation is a promising alternative in mangrove impacted by oil.

Critical study using experimental design of the determination of lead by high-resolution continuum source hydride generation atomic absorption spectrometry

The present study critically evaluates quartz tube (QT) atomisation and high-resolution continuum source hydride generation atomic absorption spectrometry (HR-CS HG-AAS) for the determination of lead. A full two-level factorial design was performed to characterise the effects of the following reagent concentrations on the analytical procedure: sodium tetrahydroborate, potassium hexacyanoferrate(III) and nitric acid. This chemometric tool demonstrated that an increasing acid concentration increases hydrogen production, which dilutes the analyte in the quartz tube during analytical measurements. The experimental conditions established in the final procedure were determined using a Box–Behnken design. The method was used to determine the concentration of lead in water samples, with limits of detection and quantification of 0.13 and 0.40 μg L−1, respectively. Method precision, expressed as relative standard deviation (RSD), was 6.36% and was obtained with a 10.00 μg L−1lead solution. The accuracy was confirmed by determining the lead concentration in the NIST standard reference material, SRM 1643d, for trace elements in natural water. This method was then used to determine the lead concentration in eighteen water samples collected in the Sao Paulo River (Bahia State, Brazil). The lead concentrations varied from 0.62 to 3.73 μg L−1. All samples were also analysed by inductively coupled plasma mass spectrometry (ICP-MS). Statistical tests demonstrated that there was no difference between the results obtained by both procedures.

Distribution and ecotoxicology of bioavailable metals and As in surface sediments of Paraguaçu estuary, Todos os Santos Bay, Brazil.

Surface sediments collected in the intertidal zone of Paraguaçu estuary in July, 2013, were analyzed for organic matter, nitrogen, phosphorus, grain size fractions and partial concentrations of 16 metals. The USEPA 3051A method and ICP-OES and CV-AAS techniques were chosen to metal analysis. Pollution indices (EF, Igeo and PIN) and a comparison with sediment quality guidelines (UET, ERL, ERM, TEL and PEL of NOAA) were conducted in order to evaluate the potential metal impacts over the area. Principal Component Analysis (PCA) and Pearson correlation results showed the importance of organic matter content and the fine-grained fraction of sediments on the control of the bioavailable metals distribution. The Paraguaçu estuary already has anthropogenic enrichment relative to the background level, especially for Mn, whose values exceeded almost 30 times the background at one site (Mn: 1197.30 mg kg(-1)). However, metal levels are still below the reference values with the exception of Hg at one site (Hg: 0.25 mg kg(-1), exceeded TEL and ERL).

Capability of Paraguaçu estuary (Todos os Santos Bay, Brazil) to form oil–SPM aggregates (OSA) and their ecotoxicological effects on pelagic and benthic organisms

For experiments concerning the formation of oil-suspended particulate matter (SPM) aggregates (OSA), oil and sediment samples were collected from Campos Basin and six stations of Paraguaçu estuary, Todos os Santos Bay, Brazil, respectively. The sediments samples were analyzed for organic matter determined by the EMBRAPA method, nitrogen determined by the Kjeldahl method, and phosphorus determined by the method described by Aspila. The oil trapped in OSA was extracted following the method described by Moreira. The experiment showed a relationship between the amount of organic matter and OSA formation and consequently the dispersion of the studied oil. On the basis of the buoyancy of OSA and the ecotoxicological effects on pelagic and benthic community, the priority areas for application of remediation techniques are Cachoeira, Maragogipe, and Salinas da Margarida because of the large amount of oil that accumulated at the bottom of the experiment flask (5.85%, 27.95%, and 38,98%; 4.2%, 17.66%, and 32.64%; and 11.82%, 8.07%, and 10.91% respectively).

Chapter 27 – Hydrocarbon Sources and Biotechnology Applications in Todos os Santos Bay, Brazil

Abstract This chapter presents advances in studies related to the monitoring and development of biotechnologies for the restoration of mangrove areas in Todos os Santos Bay that have been impacted by petroleum. The results of surface sediment monitoring show that the estuary of the Sao Paulo River has the most pollution from petroleum-derived hydrocarbons. Our biostimulation and bioaugmentation tests indicated that in relation to a control (natural attenuation), biodegradation was more rapid when using either of these techniques. The results showed greater degradation of the saturated hydrocarbons in the units receiving a nitrogen–phosphorus–potassium fertilizer blend, indicating the better biostimulation efficacy of this fertilizer. The bioaugmentation experiment indicates that the consortiums showed promise for use in bioremediation: they increased the degradation by approximately 30%. Greater efficacy in removing organic compounds from sediments was observed in two phytoremediation models (approximately 89% removal). The three models were effective in the removal of fraction 3A (C16–23), but the two phytoremediation models achieved much greater degradation of fractions 3B (C23–34) and 4 (C34–40). The data indicate that the two phytoremediation models were more effective than the intrinsic bioremediation model in the degradation of petroleum hydrocarbons.

Avaliação do teor de elementos químicos em manguezais da ilha de Itaparica, Bahia, Brasil

The content of Fe, Mn, Mo, Ni, Cu, Ba and V are reported in surface sediments of mangrove of seven settlements: Baiacu, Cacha Pregos, Jeribatuba, Misericordia, Mocambo, Campinas e Ponta Grossa. All of them from the island of Itaparica, Bahia. Values ​​equivalent to the percentage of organic matter and calcium carbonate and particle size analysis are also presented in the samples investigated. Trace and major elements were determined by ICP OES and higher concentrations (µg g-1) were found mainly in the Misericordia (Mn: 36.35 ± 1.14; Ba: 11.01 ± 1.71; V: 10.55 ± 1.81; Mo: 10.77 ±1.82) . Cacha Pregos (Mn: 26.75 ± 2.51; Ba: 9.77 ± 1.42; Cu: 20.38 ± 6.55) and Jeribatuba (Ba: 9.88 ±0.46). High concentrations of Mn in Baiacu and Ponta Grossa were also presented. Statistical analysis expressed by Pearson Correlation Matrix and Principal Component Analysis (PCA) established relationships between variables and samples studied, corroborating metal concentrations found in the samples of Misericordia, Cacha Pregos and Jeribatuba.