Optimization of high-concentration trans-anethole production through hydrodistillation of star anise
Abstract Illicium verum Hook essential oil (EO) is composed mainly of trans-anethole (TA), which has therapeutic potential. The extraction is usually by hydrodistillation, taking long hours, leaving the process costly and product with lower quality. Thus, the present study sought to optimize dehydrated fruit fragmentation by Box-Wilson central composite design and EO extraction and EO quality using a 24-1 fractional factorial design. It is concluded that the fruits must be fragmented to sizes smaller than 425 μ m using a knife mill. For hydrodistillation, the condition reported as ideal was granulometry< 0.425 mm, 8% m...
Source: Brazilian Journal of Chemical Engineering - October 1, 2019 Category: Chemistry Source Type: research

Effect of disc-blade intercepting angle on mixing performance in a multiphase stirred vessel
In this study, the effect of disc-blade intercepting angle on power number, just suspended speed and mass transfer coefficient was investigated in a multiphase system under turbulent conditions. The impellers used in this study were fabricated with 3D printing. The interactions between the experimental parameters were analysed using Response Surface Methodology (RSM). The impeller power number was found to have a linear positive relation with disc-blade intercepting angle from 30 ° to 90°. Beyond 90°, the impeller power number became lower with increment in the disc-blade intercepting angle. The results confirmed better...
Source: Brazilian Journal of Chemical Engineering - October 1, 2019 Category: Chemistry Source Type: research

CHARACTERIZATION-PERFORMANCE OF ZnO AND ZnO/ZnFe2O4 CATALYST USING ARTIFICIAL AND SOLAR LIGHT FOR MERCURY (II) REDUCTION
This study describes the application of ZnO commercial oxide and ZnO/ZnFe2O4 mixed oxides to reduce the mercury ion (Hg2+) in the aqueous phase. The catalysts synthesized were characterized by thermogravimetric analysis, adsorption and desorption of N2, scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, photoacoustic spectroscopy and M össbauer spectroscopy. The heterogeneous photocatalysis process was studied in synthetic effluent treatment containing mercury chloride (HgCl2) in a batch and solar reactor. The results indicated that commercial ZnO catalyst totally reduced the Hg (II)...
Source: Brazilian Journal of Chemical Engineering - October 1, 2019 Category: Chemistry Source Type: research

Effectiveness of phosphorus removal in an sbr using co-precipitation with ferric chloride, and its effects on microbial activity
Abstract The present study evaluated the phosphorus removal in a Sequencing Batch Reactor (SBR - 2,500L) used to treat the wastewater from an office building in two steps: phase I-Enhanced biological phosphorus removal (EBPR) and phase II-co-precipitation using FeCl3 as precipitant. The raw sewage presented a high organic load variation ranging from 0.11 (phase I) to 0.66 (phase II) kgCOD.m-3.d-1. A better phosphorus removal performance was obtained during co-precipitation (from 19.0 to 1.2 mg.L-1 = 93% of efficiency) compared with biological removal (from 15.6 to 9.0 mgL-1 = 42% of efficiency). FISH analyses did not demon...
Source: Brazilian Journal of Chemical Engineering - October 1, 2019 Category: Chemistry Source Type: research

Regulated air pollutant emissions from higher emitters stationary sources in belo horizonte, minas gerais, brazil
Abstract Belo Horizonte, capital of Minas Gerais state, is a highly urbanized city located in the third largest metropolitan area of Brazil, being one of the most important cities in the country. There are several potential air pollutant emission sources in the studied area, such as industry and the vehicular fleet (1,669,884 vehicles in 2015). These can affect the air quality, which can have an impact on population health. Despite this critical scenario, few studies have been developed with the objective of evaluating the air quality in this city, especially regarding the identification of pollutant emission sources. Thus...
Source: Brazilian Journal of Chemical Engineering - October 1, 2019 Category: Chemistry Source Type: research

Co-treatment of leachate and domestic sewage and its influence on nitrogen removal
Abstract This research investigated the performance of two pilot-scale treatment plants: an activated sludge and a hybrid model type IFAS (Integrated Fixed-Film Activated Sludge), combining sanitary landfill leachate with domestic sewage treatment with the objective of removing organic substances. In order to assess the possible impacts on the treatment, three experimental phases were developed with leachate inputs in the influent composition: 5%, 10% and 20% of the total load of BOD. As can be seen from the results, even with the highest levels of leachate input, there were no significant changes in the behavior of the bi...
Source: Brazilian Journal of Chemical Engineering - October 1, 2019 Category: Chemistry Source Type: research

BIODEGRADATION OF ACACIA AND CHESTNUT TANNINS BY NATIVE ISOLATES OF THE GENUS Penicillium AND Aspergillus
Abstract In the present work, the potential of native isolates of fungi strains to biodegrade vegetable tannins used in the tanning industry was evaluated. Penicillium citrinum showed to be more efficient for consumption of acacia tannin, reaching 94.85%. Aspergillus chevalieri needs a greater adaptation phase (48 h) in both acacia and chestnut medium, evidenced by the slow growth (0.022 h-1) and low biomass productivity (0.31 g.L-1. h-1). The acacia tannin presented a higher COD/BOD ratio (2.97) and lower total phenol content (68%) when compared to chestnut tannin. In addition, there was greater consumption of this tannin...
Source: Brazilian Journal of Chemical Engineering - October 1, 2019 Category: Chemistry Source Type: research

Potential of autochthonous sulfate-reducing microbial communities for treating acid mine drainage in a bench-scale sulfidogenic reactor
In this study, the performance and microbial diversity of anaerobic batch reactors used for sulfate reduction was evaluated. A medium COD/sulfate ratio of 1.14 ± 0.10 was used, and the evaluation was performed in two steps: Phase 1, based on the inoculum source (autochthonous, AUT, and non-autochthonous, N-AUT); and Phase 2, based on the carbon source (lactate, ethanol, and formate) and low pH. In Phase 1, the sulfate removal using both AUT and N-AUT biom asses were similar, 53% and 59%, respectively. In Phase 2, ethanol and lactate as electron donors yielded similar sulfate removal efficiencies of 42% and 44%, respective...
Source: Brazilian Journal of Chemical Engineering - October 1, 2019 Category: Chemistry Source Type: research

THERMOPHILIC BIOMETHANE PRODUCTION BY VINASSE IN AN AnSBBR: START-UP STRATEGY AND PERFORMANCE OPTIMIZATION
Abstract Thermophilic anaerobic digestion treatment of industrial wastewater generated at high temperatures can be used as an alternative for environmental pollution control and bioenergy production. Therefore, this study investigated thermophilic anaerobic reactors containing immobilized biomass (AnSBBR) to treat vinasse for methane production, in batch and fed-batch mode, in a three-step approach. In Step I (batch), the biomass was properly adapted to the thermophilic condition (55 °C) with a feed containing vinasse plus molasses as a co-substrate. In Step II (batch), the applied volumetric organic load (AVOL) was incre...
Source: Brazilian Journal of Chemical Engineering - October 1, 2019 Category: Chemistry Source Type: research

REMOVAL OF NITRATE FROM DRINKING WATER BY USING PdCu STRUCTURED CATALYSTS BASED ON CORDIERITE MONOLITHS
Abstract Structured catalysts were prepared, characterized and evaluated in NO3 - removal from drinking water. Different suspensions containing a previously optimized PdCu/5wt% ZrO2-Al2O3 powder catalyst (hereinafter PdCu/5ZAp) were prepared and deposited on cordierite monoliths by washcoating. The effect of suspension concentration, the particle size, the immersion number, the use of suspension stabilizer agent, and an alumina pre-coating on the coating adherence and catalytic performance were studied. All the prepared structured catalysts were active for the elimination of NO3 - and presented good selectivity to N2 (>...
Source: Brazilian Journal of Chemical Engineering - October 1, 2019 Category: Chemistry Source Type: research

Effect of aluminum sulfate and cationic polymer addition in the mixed liquor of a submerged membrane bioreactor (smbr): sludge characteristics and orthophosphate removal in batch experiments
This study evaluated the effect of aluminum sulfate and cationic polymer in the orthophosphate removal and sludge filterability improvement in the mixed liquor of a SMBR pilot system. Parameters such as coagulant concentration, filtration time, extracellular polymeric substances (EPS) reduction and orthophosphate removal were evaluated by using a jar-test and a stirred cell. As results, aluminum sulfate and polymer additions improved the filtration index (FI30) from 25% to 32 %, for both chemicals. Time-to-filter (TTF) results evidenced a positive and significant correlation between aluminum sulfate dosage and colloidal EP...
Source: Brazilian Journal of Chemical Engineering - October 1, 2019 Category: Chemistry Source Type: research

EFFECT OF Acidithiobacillus thiooxidans-CYSTEINE INTERACTIONS ON PYRITE BIOOXIDATION BY Acidithiobacillus ferrooxidans IN THE PRESENCE OF COAL COMPOUNDS
This study evaluated the biooxidation of pyrite contained in a Colombian coal (2.38 mm< particle size< 0.50 mm). The variables were cysteine concentration (0-600 mg/L) and culture type (pure Acidithiobacillus ferrooxidans (ATCC 23270) and a consortium of Acidithiobacillus thiooxidans (ATCC 15494) and Acidithiobacillus ferrooxidans). Pyrite oxidation for the assays without cysteine was 31.14% after 12 days. In the presence of pure A. ferrooxidans, oxidation increased by 8.18% in the assays containing 60 mg Cys/L. In contrast, the counterpart using the consortium exhibited a significant increase in redox potential, whi...
Source: Brazilian Journal of Chemical Engineering - October 1, 2019 Category: Chemistry Source Type: research

REMOVAL OF TRIBUTYL PHOSPHATE FROM AQUEOUS SOLUTIONS BY TiO2 HETEROGENEOUS PHOTOCATALYSIS SUPPORTED OVER A NEW METAL PLATE WITH KINETIC STUDY
Abstract The aim of this investigation was to study the degradation of tributyl phosphate (TBP) in aqueous solution by heterogeneous photocatalysis (UV-C/TiO2). To perform the investigation, aqueous solutions containing the contaminant were exposed to UV radiation in the absence or presence of TiO2 in suspension or supported on a Fe-Cr metal alloy plate. TBP analyses before and after the treatment were performed by Ultra-Performance Liquid Chromatography (UPLC) in order to quantify the contaminant degradation. The results showed that the TiO2 photocatalytic system was able to remove TBP from the solution and the formation ...
Source: Brazilian Journal of Chemical Engineering - October 1, 2019 Category: Chemistry Source Type: research

SYNTHESIS AND CHARACTERIZATION OF FRUCTOSYLTRANSFERASE FROM Aspergillus oryzae IPT-301 FOR HIGH FRUCTOOLIGOSACCHARIDES PRODUCTION
Abstract Fructooligosaccharides (FOS) are mainly produced by microbial fructosyltransferases (FTase, E.C.2.4.1.9), and Aspergillus oryzae IPT-301 has shown high fructosyl transferring and low hydrolytic activities, which leads to high FOS production yields, but the main operating parameters for its best performance have been scarcely studied. Thus, this work aimed to evaluate the cellular growth, production and characterization of mycelial and extracellular FTases by Aspergillus oryzae IPT-301. Experimental design showed that the extracellular FTase performance was optimized (high transfructosylation activity and low hydro...
Source: Brazilian Journal of Chemical Engineering - October 1, 2019 Category: Chemistry Source Type: research

LIPIDS AS COMPETITIVE INHIBITORS OF SUBTILISIN CARLSBERG IN THE ENZYMATIC HYDROLYSIS OF PROTEINS IN RED TILAPIA (Oreochromis sp.) VISCERA: INSIGHTS FROM KINETIC MODELS AND A MOLECULAR DOCKING STUDY
The objective of this research article was to study the effect of lipids on the enzymatic kinetics of red tilapia viscera (RTV) hydrolysis with subtilisin Carlsberg. The RTV were hydrolyzed in an enzyme/substrate ratio of 0.153 (U/g), at 53 ° C, at a pH of 9.5, initial concentrations of lipids of 1, 19 and 50 g/L, and different initial substrate concentrations for each initial lipid concentration. To explain the lipid action mechanism, we evaluated a Michaelis-Menten model and another semi-physical model based on kinetic expressions a nd mass balances. Additionally, a molecular docking analysis was performed between subti...
Source: Brazilian Journal of Chemical Engineering - October 1, 2019 Category: Chemistry Source Type: research