Brazilian Journal of Chemical Engineering This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

Different stages of liquid film growth in a microchannel: two-phase lattice boltzmann study
Abstract A free energy model is used to describe the droplet formation and break-up process in a T-junction bio-microchannel. Droplets are created as a result of interaction of two immiscible liquids. Different stages for the droplet formation process are analyzed which are: a) growing in the x and y directions, b) growing in the x direction and c) detachment process. The effects of capillary number and flow rate ratio on the droplet formation stages are also studied. The influences of Capillary number, flow rate ratio, viscosity ratio and geometrical parameters on droplet break up, droplet size and detachment time are sys...
Source: Brazilian Journal of Chemical Engineering - January 21, 2019 Category: Chemistry Source Type: research

Statistical optimization of ettringite precipitation in landfill leachate
Abstract In the present study, experiments were conducted to optimize sulfate removal efficiency with ettringite precipitation from landfill leachate using Response Surface Methodology (RSM) and Central Composite Design (CCD). The statistical analysis of the results showed that the operating parameters such as molar rates of Ca/SO4 and Al/SO4, and pH had a significant effect on sulfate removal efficiency. Aluminum hydroxide and calcium hydroxide were used for external sources of aluminum and calcium. The goodness of the model was checked by different criteria including the coefficient of determination (R2 = 0.94), p value ...
Source: Brazilian Journal of Chemical Engineering - January 21, 2019 Category: Chemistry Source Type: research

Evaluation of direct photolysis, electrooxidation and photoelectrooxidation for rhodamine-b degradation
Abstract The focus of this study is to evaluate the efficiency of oxidation processes in the treatment of a solution containing Rhodamine-B (RhB) used in various industrial applications. The advanced oxidation processes of electrooxidation (EO) and photoelectrooxidation (PEO) were used. At the same time, direct photolysis (DP) was also applied. Total organic carbon (TOC) reduction and color removal were evaluated. There was an efficient color removal when DP was performed, and the color removal efficiency was the highest when NaCl was used as supporting electrolyte for PEO and EO. However, the TOC reduction was low, indica...
Source: Brazilian Journal of Chemical Engineering - January 21, 2019 Category: Chemistry Source Type: research

Modeling and optimization of removal of cefalexin from aquatic solutions by enzymatic oxidation using experimental design
Abstract Antibiotics are used globally and, after use, they enter water sources in different ways. The presence of these compounds in the environment has created concerns about the toxicity of aquatic organisms and the emergence of antibiotic-resistant bacteria. The purpose of this study was to remove cefalexin from aqueous solutions by enzymatic oxidation using response surface methodology (RSM). For this purpose, batch experiments were performed to evaluate the effect of independent variables, including temperature, pH, contact time, enzyme activity, HBT mediator concentration, and antibiotic concentration. The residual ...
Source: Brazilian Journal of Chemical Engineering - January 21, 2019 Category: Chemistry Source Type: research

Gold recovery from printed circuit boards of mobile phones scraps using a leaching solution alternative to cyanide
Abstract Currently, the printed circuit boards (PCB) of waste electrical and electronic equipment (WEEE) are attracting interest among researchers for environmental concern reasons and mainly for their content of precious metals such as gold. Thus, this study aims to characterize different types of PCBs from mobile phones in relation to the amount of gold contained, to evaluate alternative leaching agents for the gold (ammonium and sodium thiosulfate) and compare these to commercial stripping (cyanide-based) and then the recovery of gold by the electrometallurgical route. First, the amount of gold was determined. Then, alt...
Source: Brazilian Journal of Chemical Engineering - January 21, 2019 Category: Chemistry Source Type: research

Separation of copper from a leaching solution of printed circuit boards by using solvent extraction with d2ehpa
Abstract Global generation of waste electrical and electronic equipment (WEEE) is increasing quickly. Metals from WEEE can be recovered by using unit operations of chemical engineering. This paper describes a combined hydrometallurgical route (sulfuric oxidant leaching + solvent extraction) to recover copper from printed circuit boards (PCBs). A non-magnetic fraction from comminuted PCBs was used to perform leaching tests at 75 ºC for 6 hours in an oxidizing media (sulfuric acid + hydrogen peroxide). In order to separate zinc, aluminum, and copper from the leaching liquor, solvent extraction tests were carried out using D...
Source: Brazilian Journal of Chemical Engineering - January 21, 2019 Category: Chemistry Source Type: research

Ultrasonic pre-treatment of wastewater sludge from a meat processing industry
Abstract This investigation deals with ultrasonic disintegration of sludge taken from a meat processing wastewater treatment plant. Different specific energy inputs ranging between 0 and 100 MJ/kg Total Solids (TS) were used in the study. The effect of ultrasonic pre-treatment on anaerobic biodegradability and filterability characteristics of sludge were evaluated using lab-scale experiments. 30 MJ/kg TS of supplied energy is efficient for cell lyses. Ultrasonic pre-treatment significantly enhanced the biodegradability of sludge. Biochemical methane potential test results also supported this result. For 30 MJ/kg TS, 2.4 ti...
Source: Brazilian Journal of Chemical Engineering - January 21, 2019 Category: Chemistry Source Type: research

CAN VINASSE BE USED AS CARBON SOURCE FOR POLY(3-HYDROXYBUTYRATE) PRODUCTION BY Cupriavidus necator DSM 545?
Abstract Vinasse is the main liquid waste of the ethanol industry and its valorization by a bioprocess as a substrate for production of a value-added product contributes to the ethanol process. This work aimed to study the possibility to use vinasse for poly(3-hydroxybutyrate) (PHB) production by Cupriavidus necator. The growth of C. necator was evaluated using different vinasse concentrations and no inhibitory effect was observed. Cultivations in a bioreactor were carried out with pure vinasse, vinasse with nitrogen and vinasse with nitrogen and mineral salts. The best values of total biomass (5.1 g.L-1) and PHB (26% of t...
Source: Brazilian Journal of Chemical Engineering - January 21, 2019 Category: Chemistry Source Type: research

HIGHLY EFFICIENT PRODUCTION OF L (+)-LACTIC ACID USING MEDIUM WITH POTATO, CORN STEEP LIQUOR AND CALCIUM CARBONATE BY Lactobacillus rhamnosus ATCC 9595
The objective of this study was to optimize the composition of the fermentation medium through a Central Composite Rotational Design (CCRD) for the production of L (+)- latic acid (LA) using Lactobacillus rhamnosus ATCC 9595 and potato, corn steep liquor (CSL) and calcium carbonate as raw materials. A CCRD with three independent variables (potato fl our (PF), CSL and CaCO3 concentrations) was performed for a total of 17 treatments. Kinetic studies were conducted, and samples were taken at time intervals of 0 to 72 h. Cell count, pH, reducing sugars and LA concentrations were determined. LA productivity and yield, sugar co...
Source: Brazilian Journal of Chemical Engineering - January 21, 2019 Category: Chemistry Source Type: research

MODELING THE CORE METABOLISM OF Komagataeibacter hansenii ATCC 23769 TO EVALUATE NANOCELLULOSE BIOSYNTHESIS
Abstract Genome-scale metabolic models based on a combination of genome sequence and biochemical information have strongly influenced the field of systems biology. However, basic principles of the operation of metabolic networks, in particular the central metabolism can be easily studied in smaller metabolic (core) models. Komagataeibacter hansenii ATCC 23769 has been used for bacterial nanocellulose (BNC) biosynthesis, and the recent availability of its genome sequence allowed the development of a metabolic model. The core metabolic model was constructed from an initial draft metabolic reconstruction including 74 reaction...
Source: Brazilian Journal of Chemical Engineering - January 21, 2019 Category: Chemistry Source Type: research

SIMULTANEOUS PRODUCTION OF BIOSURFACTANTS AND LIPASES FROM Aspergillus niger AND OPTIMIZATION BY RESPONSE SURFACE METHODOLOGY AND DESIRABILITY FUNCTIONS
In this study the simultaneous production of biosurfactants and lipases by Aspergillus niger in a submerged bioprocess was analyzed. Full Factorial Design (23) was conducted to assess the influence of the malt extract (g ·L-1; 25, 50, 75) and soybean oil concentrations (% v/v; 0.0, 1.25, 2.5) and agitation rates (rpm; 0.0, 100, 200) on biosurfactant and lipase production. Higher levels of the factors favored microbial growth, while their lower levels favored the production of biosurfactants and lipases. The variabl es were optimized through the response surface methodology and desirability functions, obtaining simultaneou...
Source: Brazilian Journal of Chemical Engineering - January 21, 2019 Category: Chemistry Source Type: research

APPLICABILITY OF WOOL COVALENT BONDED Bacillus circulans 25 CELLS FOR MILK-CLOTTING ENZYME PRODUCTION BY BATCH, REPEATED BATCH AND CONTINUOUS PROCESS
Abstract The production of milk-clotting enzyme (MCE) by free and immobilized Bacillus circulans 25 cells was investigated. The investigation evaluates cell immobilization through entrapment and covalent binding to different carriers. B. circulans 25 cells immobilized covalently via glutaraldehyde (cross-linker) to natural wool exhibited higher effectiveness factor (0.76) compared to other carriers. Immobilized cells produce maximum level of MCE and highest ratio of milk-clotting activity/proteolytic activity (MCA/PA) after 24 h using 0.4g wet weight cells/g wool. In batch operation, decreasing biomass loading to 0.2 g enh...
Source: Brazilian Journal of Chemical Engineering - January 21, 2019 Category: Chemistry Source Type: research

Production of polyunsaturated fatty acids by microorganisms isolated in the brazilian pampa biome
Abstract One hundred fifty fungal strains were isolated from the Pampa biome for production of polyunsaturated fatty acids (PUFA). Microbial oil was produced by submerged cultivation at 120 rpm, 28 ºC for 7 days. Seven strains showed the best results for lipids accumulation, and they were selected in order to evaluate the influence of the temperature (15 and 28 ºC) on the lipid production and profile. The fungus Nigrospora sp. produced the highest lipid level: at 28 ºC were produced 11.28% of lipids and 51.94% of PUFA and at 15 ºC were produced 6.02% of lipids and 42.39% of PUFA. Plackett Burman design was performed to...
Source: Brazilian Journal of Chemical Engineering - January 21, 2019 Category: Chemistry Source Type: research

Liquid-liquid equilibria for systems containing fatty acid ethyl esters, ethanol and glycerol at 333.15 and 343.15 k: experimental data, thermodynamic and artificial neural network modeling
In this study, the liquid-liquid equilibrium (LLE) data of systems containing ethyl linoleate/oleate/palmitate/laurate, ethanol and glycerol at temperatures ranging from 323.15 to 353.15 K were used to evaluate the performance of the NRTL, UNIFAC, Cubic-Plus-Association Equation of State (CPA EoS), and artificial neural network (ANN) models. The systems evaluated correspond to the most important components formed at the end of the ethanolysis reaction of soybean, palm and coconut oils. The temperature range selected is very important for heterogeneous catalysts, especially for high-pressure systems. The accuracy of the mod...
Source: Brazilian Journal of Chemical Engineering - October 5, 2018 Category: Chemistry Source Type: research

Development and optimization of a single-step cation chromatographic whey protein fractionation process: evaluation and comparison of scale-up strategies
Abstract This manuscript presents evaluation of various strategies used for the scale-up of chromatographic purification systems. Towards that end, the manuscript provides development and optimization of a single-step whey protein concentrate (WPC) fractionation process at lab scale on a 1.0 × 19 cm column using UNOsphere S. Subsequently, scale-up of this newly developed process and conduction of trials at higher scale is also undertaken by applying various scale-up strategies. For these trials, this work categorized various scale-up factors into constant velocity (CV) and constant bed volume per hour (CBVH) scale-up met...
Source: Brazilian Journal of Chemical Engineering - October 5, 2018 Category: Chemistry Source Type: research