Lívian Ribeiro Vasconcelos de Sá

The Use of HRP in Decolorization of Reactive Dyes and Toxicological Evaluation of Their Products

This work studied the potential use of horseradish peroxidase (HRP) in the decolorization of the following textile dyes: Drimarene Blue X-3LR (DMBLR), Drimarene Blue X-BLN (DMBBLN), Drimarene Rubinol X-3LR (DMR), and Drimarene Blue CL-R (RBBR). Dyes were individually tested in the reaction media containing 120 mg·L−1, considering the following parameters: temperature (20–45°C), H2O2 concentration (0–4.44 mmol·L−1), and reaction time (5 minutes, 1 and 24 h). The following conditions: 35°C, 0.55 mmol·L−1, and 1h, provided the best set of results of color removal for DMBLR (99%), DMBBLN (77%), DMR (94%), and RBBR (97%). It should be mentioned that only 5 minutes of reaction was enough to obtain 96% of decolorization for DMBLR and RBBR. After the decolorization reactions of DMBLR, DMR, and RBBR, it was possible to observe the reduction of Artemia salina mortality and the no significant increase in toxicity for the products generated from DMBBLN.

Produção de hidrogênio via fermentação anaeróbia - aspectos gerais e possibilidade de utilização de resíduos agroindustriais brasileiros

Biological production of hydrogen through anaerobic fermentation has received increasing attention and offers a great potential as an alternative process for clean fuel production in the future. Considering biological systems for H2 production, anaerobic fermentation stands out, primarily due to its higher production of H2 compared with other biological processes. In addition the possibility of using different agro-industrial wastes as substrates opens up infinite possibilities. The development and implementation of sustainable processes for converting renewable materials into different value-added products is essential for the full exploitation of Brazilian agro-industrial wastes.

Monitoring of atrazine biodegradation by Pleurotus ostreatus INCQS 40310 through the simultaneous analysis of atrazine and its derivatives by HPLC

Abstract Atrazine is a widely used herbicide on crops of major economic relevance such as corn and sugarcane. The widespread use of this herbicide could result in its accumulation in, or contamination of environmental niches. It is important to emphasize that not only atrazine but also its derivatives should be monitored. The aim of this study was to develop an appropriate methodology for simultaneous separation of atrazine (ATZ) and its derivatives, desethylatrazine (DEA), deisopropylatrazine (DIA), hydroxyatrazine (HA), desethyldeisopropylatrazine (DEDIA), desethylhydroxyatrazine (DEHA), and deisopropylhydroxyatrazine (DIHA) using high-performance liquid chromatography (HPLC). HPLC analyses were performed under gradient elution mode using a Shim-pack VP ODS C18 (250 × 4.6 mm, 4.6 μm) column, 5 mmol.L− 1 of sodium phosphate buffer (pH 7.2) and acetonitrile as the mobile phase at a flow rate of 1 mL.min− 1 and 25°C. Detection was monitored at 221 nm. Some validation parameters, such as selectivity, linearity, precision, accuracy, limit of detection and limit of quantification were evaluated for analyses of atrazine, DEA, and DEDIA. The method was successfully applied to the detection of DEA and DIA, the main degradation products observed after 15 days of incubation in the presence of Pleurotus ostreatus INCQS 40310. The formation of DEA and DIA was unequivocally confirmed by GC-MS.

Productive Chain of Biofuels and Industrial Biocatalysis: Two Important Opportunities for Brazilian Sustainable Development

Abstract The integration between biofuels and chemicals production from biomass stimulates the transition to the inevitable bioeconomy era; this era can be achieved by implementing new technologies in existing industrial units where waste streams and by-products can be used as a renewable source of raw materials for the production of commodities and other value-added chemicals. This synergistic approach requires less capital investment, creates new business and job opportunities, expands the market and reduces the environmental impact caused by the operation of industrial plants. This chapter depicts the current situation of the two main biofuels in Brazil, ethanol and biodiesel, and introduces the discussion of opportunities and bottlenecks in the exploitation of lignocellulosic and oleaginous materials, focusing on the important role of enzymatic and microbial processes to support a sustainable industry.