Biosorption of BF-4B Reactive Red Dye by using Leaves of Macrophytes Eichhornia crassipes

The removal potential on BF-4B reactive red dye by Eichhornia crassipes dried leaves has been investigated. Furthermore, the influence of process parameters such as solution pH, agitation, and particle size on the dye adsorption efficiency was assessed. Both kinetic and equilibrium experiments were performed in batch operation of the system. Kinetic results demonstrated that the equilibrium state was achieved after 45 min process time. The kinetic experimental data were best described by applying a pseudo-second order model that evaluated the value of rate constant 0.22 g/mg/min and an equilibrium dye concentration 8.20 mg/g. A set of isotherm models, taken from knowledge database, was tested in order to represent the equilibrium adsorption data. The Langmuir model performed the best when fitting experimental data where the maximum adsorption capacity of 20.38 mg/g was achieved. The results demonstrated that the E. crassipes has good potential to be used as a biosorbent in industrial treatment systems to remove reactive dyes from textile effluents

Desenvolvimento de um modelo da cinética enzimática da transesterificação de óleos vegetais para produção de biodiesel = Development of the enzymatic kinetics model of vegetable oils transesterification for biodiesel production

Atualmente, a tecnologia de produção enzimática do biodiesel é mais uma alternativa em relação aos métodos químicos que utilizam catalisadores ácidos ou básicos. A enzima lipase utilizada como catalisador desse processo pode ser obtida de microrganismoscomo Pseudomonas fluorescens, P. cepacia, Candida antarctica, dentre outros. Neste trabalho, propomos um mecanismo da transesterificação de triglicerídeos catalisada por enzima lipase. O processo foi formalizado em três reações consecutivas, nas quais são formados osdiglicerídeos e monoglicerídeos. Outras três etapas intermediárias das reações envolvendo a lipase foram consideradas. A identificação dos parâmetros do modelo desenvolvido foi feita para condições reacionais em que a alimentação é feita na proporção estequiométrica dos reagentes. O modelo desenvolvido foi testado com dados experimentais em diversas condições operacionais encontradas na literatura. Os resultados das simulações mostram boa flexibilidade do modelo, ajustando os dados em várias condições de transesterificaçãoenzimática para produção de biodiesel.Currently the technology of enzymatic production of biodiesel is more promising than that based on chemical methods, using acidic orbasic catalysts. The enzyme lipase used as catalyst in this process can be isolated from microorganisms such as Pseudomonas fluorescens, P. cepacia, Candida antarctica among others. In this work, a mechanism for the transesterification of triglycerides catalyzed by lipase for production of biodiesel is proposed. The process was modeled in three consecutive reactions where diglycerides and monoglycerides were formed. Other three intermediate stages involving lipase were considered. The identification of parameters with the developed model was performed for reaction conditions where stoichiometric amount of reagents were used. The developed modelwas tested for different operational conditions with experimental data found in the literature. The simulation results showed good model flexibility

<b>Desenvolvimento de um modelo da cinética enzimática da transesterificação de óleos vegetais para produção de biodiesel</b> - DOI: 10.4025/actascitechnol.v29i1.79

Atualmente, a tecnologia de produção enzimática do biodiesel é mais uma alternativa em relação aos métodos químicos que utilizam catalisadores ácidos ou básicos. A enzima lipase utilizada como catalisador desse processo pode ser obtida de microrganismos como <em>Pseudomonas fluorescens, P. cepacia, Candida antarctica</em>, dentre outros. Neste trabalho, propomos um mecanismo da transesterificação de triglicerídeos catalisada por enzima lipase. O processo foi formalizado em três reações consecutivas, nas quais são formados os diglicerídeos e monoglicerídeos. Outras três etapas intermediárias das reações envolvendo a lipase foram consideradas. A identificação dos parâmetros do modelo desenvolvido foi feita para condições reacionais em que a alimentação é feita na proporção estequiométrica dos reagentes. O modelo desenvolvido foi testado com dados experimentais em diversas condições operacionais encontradas na literatura. Os resultados das simulações mostram boa flexibilidade do modelo, ajustando os dados em várias condições de transesterificação enzimática para produção de biodiesel

A comprehensive evaluation of heavy metals removal from battery industry wastewaters by applying bio-residue, mineral and commercial adsorbent materials

We present a feasibility study of different adsorbent materials, namely residual fish scales biosorbent (FS), mineral dolomite (DL) and commercial resin (CR) in the heavy metals removal in multicomponent solution based on the properties of a real effluent from automotive battery recycling industry. Considering the effluent complex characteristics, the materials were assessed aiming to provide not only the heavy metals removal, but also the effluent neutralization and lower sludge generation. For this, all the studied materials were physicochemically and morphologically characterized with the aim of understanding the mechanisms involved in the process. Further, the elemental compositions of the solid and liquid phases generated from each treatment process were assessed by X-ray fluorescence spectrometry. The effluent presented highly acidic characteristics and heavy metals above the legislated limits for discharge (Fe, Zn and Pb). Each adsorbent material followed different mechanisms which led to dissimilar removal and neutralization capacities. The CR showed remarkable heavy metals removal capacity governed by an ion exchange mechanism; conversely, it did not show a neutralization effect. In contrast, FS and DL presented lower removal capacities by complex simultaneous phenomena (ion exchange, precipitation and/or complexation), but a great neutralization potential related to leaching of alkaline constituents. When sludge generation is considered as a key factor, mitigation and enhancement of treated effluent quality could alternatively be addressed by employing the materials in hybrid processes. Hence, the associated use of such materials could be viable yet very challenging for both neutralization and removal of heavy metals from the battery effluent531179767995CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ480107/2013-

Micellar curcumin improves the antibacterial activity of the alkylphosphocholines erufosine and miltefosine against pathogenic Staphyloccocus aureus strains

In the light of the emerging bacterial resistance to broad-spectrum antibiotics, the search for new antibacterial therapeutics and drug combinations is one of the most challenging topics nowadays. In the present study, we investigated for the first time the antibacterial and biofilm inhibitory effects of the third generation anticancer alkylphosphocholine (APC) erufosine against pathogenic Staphylococcus aureus strains in comparison to the prototype of this pharmacological class of drugs, miltefosine. We also searched for synergistic antibacterial combinations between both APCs and curcumin incorporated in copolymeric micelles based on Pluronic® P123 or a mixture of Pluronic® P123 and Pluronic® F127 (P123/F127). The obtained quantitative redox-activity experimental data and drug–drug interactions were evaluated by using mathematical models in the MAPLE software. Similar to miltefosine, erufosine showed a moderate bacteriostatic effect in clinically relevant concentrations (50 ÷ 60 µmol/L) and inhibited the redox activity of the treated bacteria up to 90% at minimal inhibitory concentrations. The effect of both APCs towards methicillin resistant staphylococci was enhanced by combinations with P123/F127 micellar CRM at a ratio of 1:1. Erufosine showed a stronger median biofilm inhibition at lower concentrations (MBIC50 = 1.87 µmol/L) than miltefosine (MBIC50 = 6.0 µmol/L) and curcumin (MBIC50 = 24.84 µmol/L) as demonstrated by quantification of biofilm-bound bacteria. In conclusion, the estimated antibacterial activity of erufosine widens the spectrum of its useful pharmacological effects, which is important for its clinical development. The established synergistic and additive drug combinations could be beneficial for the application of both APCs in cancer therapy, since numerous malignancies are accompanied by bacterial infections

Chromium ions phytoaccumulation by three floating aquatic macrophytes from a nutrient medium

In the present work, the trivalent and hexavalent chromium phytoaccumulation by three living free floating aquatic macrophytes Salvinia auriculata, Pistia stratiotes, and Eicchornia crassipes was investigated in greenhouse. These plants were grown in hydroponic solutions supplied with non-toxic Cr3+ and Cr6+ chromium concentrations, performing six collections of nutrient media and plants in time from a batch system. The total chromium concentrations into Cr-doped hydroponic media and dry roots and aerial parts were assayed, by using the Synchrotron radiation X-ray fluorescence technique. The aquatic plant-based chromium removal data were described by using a nonstructural kinetic model, obtaining different bioaccumulation rate, ranging from 0.015 to 0.837 1 mg(-1) d(-1). The Cr3+ removal efficiency was about 90%, 50%, and 90% for the E. crassipes, P. stratiotes, and S. auriculata, respectively; while it was rather different for Cr6+ one, with values about 50%, 70%, and 90% for the E. crassipes, P. stratiotes, and S. auriculata.Brazilian Synchrotron Light Laboratory (LNLS)The Brazilian Light Synchrotron Laboratory (LNLS)[3364]Brazilian Synchrotron Light Laboratory (LNLS)The Brazilian Light Synchrotron Laboratory (LNLS)[4652

Adsorption of Direct of Yellow ARLE Dye by Activated Carbon of Shell of Coconut Palm: Diffusional Effects on Kinetics and Equilibrium States

In this paper, the characteristics and potential removal of direct yellow ARLE (DYA) dye by using coconut palm shell-based activated carbon (CPS-AC) were assessed. Both kinetic and equilibrium experimental data were obtained from a series of DYA dye sorption experiments. All the sorption experiments were performed in closed batch system under constant temperature and stirring speed, at the predetermined pH of initial solution. The kinetic mathematical models of pseudo-first order, pseudo-second order, Elovich and intra-particle diffusion model were used in order to better interpret the adsorption kinetics phenomenon. Equilibrium data were described by applying the isotherm models of Langmuir, Freundlich, Tóth, Sips and Khan. The best description of DYA sorption equilibrium data was achieved for the Langmuir isotherm model, reaching a maximum adsorption capacity of 100 mg·g-1. Finally, the DYA dye adsorption functional groups characterizations were successfully accomplished and the results elucidated the most important groups linked with CPS-AC surface where molecular interactions could occur. Hence, the quantitative evaluation of equilibrium and kinetic experiments of adsorption process have demonstrated that the CPS-AC adsorbent was a promising high effective adsorbent and its potential can be successfully used for DYA dye removal

Antimicrobial and Antioxidant Potential of Scenedesmus obliquus Microalgae in the Context of Integral Biorefinery Concept

Small-scale photobioreactors (PBRs) in the inoculum stage were designed with internal (red or green) and external white LED light as an initial step of a larger-scale installation aimed at fulfilling the integral biorefinery concept for maximum utilization of microalgal biomass in a multifunctional laboratory. The specific growth rate of Scenedesmus obliquus (Turpin) K&uuml;tzing biomass for given cultural conditions was analyzed by using MAPLE software. For the determination of total polyphenols, flavonoids, chlorophyll &ldquo;a&rdquo; and &ldquo;b&rdquo;, carotenoids and lipids, UHPLC-HRMS, ISO-20776/1, ISO-10993-5 and CUPRAC tests were carried out. Under red light growing, a higher content of polyphenols was found, while the green light favoured the flavonoid accumulation in the biomass. Chlorophylls, carotenoids and lipids were in the same order of magnitude in both samples. The dichloromethane extracts obtained from the biomass of each PBR synergistically potentiated at low concentrations (0.01&ndash;0.05 mg/mL) the antibacterial activity of penicillin, fluoroquinolones or oregano essential oil against the selected food-borne pathogens (Staphylococcus aureus, Escherichia coli and Salmonella typhimurium) without showing any in vitro cytotoxicity. Both extracts exhibited good cupric ion-reducing antioxidant capacity at concentrations above 0.042&ndash;0.08 mg/mL. The UHPLC-HRMS analysis revealed that both extracts contained long chain fatty acids and carotenoids thus explaining their antibacterial and antioxidant potential. The applied engineering approach showed a great potential to modify microalgae metabolism for the synthesis of target compounds by S. obliquus with capacity for the development of health-promoting nutraceuticals for poultry farming