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Made available in DSpace on 2018-12-11T17:36:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-07-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Technical, economic and environmental aspects of implementing two-phase anaerobic digestion (AD), i.e., acidogenic + methanogenic systems, in sugarcane biorefineries for the treatment of vinasse were assessed based on different strategies to using the hydrogen-rich biogas (biogas-H2) generated via acidogenesis. Phase separation greatly enhanced the bioenergy recovered from vinasse AD compared with single-phase systems (methanogenic phase exclusively). The best results for generating electric energy were observed in combined cycle-based power plants that utilized biohythane (10.8 MW + 5.5 MW for the harvest and inter-harvest, respectively), which is the gaseous biofuel from blending biogas-H2 with the methane-rich stream from the methanogenic phase (biogas-CH4). Moreover, the results of this study indicated that scaling up two-phase AD systems is economically feasible for the treatment of sugarcane vinasse (net present value = USD 208.58–219.86 million) because a better or equivalent economic performance was attained compared with single-phase processes. Optimizing the alkalinization of methanogenic reactors strongly affected both the economic and environmental performance of the process, with better results observed with the use of low sodium hydroxide dosages (4 g NaOH kg−1COD). In summary, our results highlighted that two-phase biodigestion may enhance energy production from vinasse by 20–30% without impairing the profitability of the biorefinery and could lead to slight improvements in the environmental performance of the ethanol production chain via the use of an optimized alkalinization strategy. Biological Processes Laboratory (LPB) São Carlos School of Engineering (EESC) University of São Paulo (USP), Av. João Dagnone, 1100, Santa Angelina Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE) Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Rua Giuseppe Máximo Scolfaro, 10000, Polo II de Alta Tecnologia, P.O. Box 6170 São Paulo State University (UNESP) Institute of Geosciences and Exact Sciences (IGCE), Campus of Rio Claro. Av. 24-A, 1515, Bela Vista São Paulo State University (UNESP) Institute of Geosciences and Exact Sciences (IGCE), Campus of Rio Claro. Av. 24-A, 1515, Bela Vista FAPESP: 2009/15984-0 FAPESP: 2012/15606-9

Made available in DSpace on 2021-06-25T10:59:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-06-01 This work reports the development of a fast and reliable amperometric sensor for the detection of amino acids. The detector was constructed using copper nanoparticles (CuNPs) supported on reduced graphene oxide (RGO) modified glassy carbon electrode (CuNPs-RGO/GCE) and based on the application of high performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). Under optimized isocratic HPAEC-PAD conditions (using 40 mmol L−1 NaOH as mobile phase, flow rate of 0.30 mL min−1 and detection potential of 0.45 V vs. Pd/PdO), the linear dynamic ranges of the concentration of amino acids obtained were 0.50–50 µmol L−1 for lysine, 1.0–100 µmol L−1 for alanine, glycine and serine, and 5.0–100 µmol L−1 for leucine. The limits of detection (S/N = 3) obtained ranged from 0.10 (for lysine and leucine) to 0.50 µmol L−1 (for alanine, glycine and serine) and sensitivity varied from 6.1 (for leucine) to 21.5 nA µmol−1 L (for serine). The average recovery percentages ranged from 97% (for glycine) to 102% (for leucine and serine). The results obtained showed that the CuNPs-RGO/GCE has good long-term stability, repeatability and reproducibility; this makes the device suitable for application as an electrochemical detector. The successful application of the proposed method for the analysis of sugarcane vinasse demonstrates its suitability for separation and determination of amino acids in complex matrices. Analytical Chemistry Department Institute of Chemistry São Paulo State University (UNESP) Bioenergy Research Institute São Paulo State University (UNESP) Analytical Chemistry Department Institute of Chemistry São Paulo State University (UNESP) Bioenergy Research Institute São Paulo State University (UNESP)

This work evaluated the degradation of sugarcane vinasse with the production of biomass by Pleurotus sajor-caju CCB020, considering the combination of temperature and pH effects, using surface response methodology (RSM). A 22 complete central factorial composite experiment was used to analyze the results. The optimum temperature and pH values were respectively 27°C and 5.6 for maximum decolorization yield and 20°C and 6.8 for maximum biomass production. In parallel, scale-up experiments under conditions of 30°C and initial pH 5.0 were evaluated in two different air-lift bioreactors of 7.0L. Under these conditions, reductions of 53% and 58% in chemical oxygen demand (COD) and 71% and 58% in biological oxygen demand (BOD) were obtained respectively with the concentric tube type air-lift bioreactor with an increased degassing zone and without an increased degassing zone. Under these conditions, this study concluded that the systematic combination of P. sajor-caju and vinasse can be applied in the biodegradation process of refractory compounds contained in vinasse, concomitant to obtaining biomass and laccase and manganese peroxidase enzymes. Due to the good performance of the air-lift bioreactors, they can be used in scale studies in future industrial vinasse applications, besides it is possible to emphasize that different configurations in the bioreactor can affect the efficiency of the process., Supplementary data to this article can be found online at: https://doi.org/10.1016/j.chemosphere.2019.125432., info:eu-repo/semantics/publishedVersion

Vinasse is a key by-product of the ethanol manufacturing industry. Several processes have been studied for the first time in order to treat sugarcane vinasse. Removals of the absorbances (220, 254 and 410 nm) and nutrients (Ca, Mg, P, N, K and Na)≤36% were achieved in the H2SO4 precipitation with the production of a low sludge volume (rich in organic matter and magnesium). A nominal chemical oxygen demand (COD) decline = 12% was also noted when using H2SO4 precipitation, owing to the presence of soluble organic acids in vinasse. Operating pH in the Ca(OH)2 precipitation affected the removal of COD, absorbances and nutrients, obtaining high efficiencies (COD = 51%, absorbances = 88–100%, Mg = 91%, N = 74%, K = 37%, P = 95%, Na = 20%) for high precipitation pH (12–12.5). High depletions in the Ca(OH)2 precipitation can be explained by the formation of insoluble species and polymerization and precipitation of fatty acids, producing a sludge rich in Ca, P, K and Mg. Comparable results were attained for the thermocalcic precipitation. NaOH precipitation treatability for the vinasse decontamination was based on the removals of Ca (80%), P (74%), Mg (64%), N (24%), K (19%), generating a sludge rich in organic matter and nutrients (Mg, K, P and Na). The supernatant produced in the Ca(OH)2 precipitation, under optimal conditions, was subjected to: 1) a coagulation-flocculation step with FeCl3 addition (1 g L−1), improving the removals of absorbance at 410 nm, COD, phosphorus and volatile solids (VS); and 2) a novel green technology (natural carbonation) for the atmospheric CO2 mitigation with treatment and neutralization of the effluent.