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The present work presents the results of the production of vanillin-doped alginate biofilm. Alginate dressings are already a therapeutic reality, but they act only by maintaining the appropriate environment for healing. With the intention of improving their properties, the incorporation of vanillin was proposed due to its antioxidant and antimicrobial potential. Different biofilms were produced employing experiment planning through response surface analysis, which allowed determining the best region for a medium value of solubility and high degree of intumescence. This region refers to values above 0.07 g of CaCl2 and concentrations above 0.024 g of vanillin, triggering a solubility between 25% and 30% and a degree of intumescence above 100% and with fixed values of alginate (0.85 g). As for the optimization of the process, the Normal Boundary Intersection (NBI) method was able to analyze concave regions, predicting the optimal points and generating the Pareto chart with equidistant limits The antimicrobial test allowed the observation of antimicrobial activity against Escherichia coli and Pseudomonas aeruginosa microorganisms from the biofilms, as well as a solution of vanillin with calcium chloride and glycerol obtaining a halo of inhibition only in the presence of vanillin. Thermal analysis of thermogravimetry and differential exploratory calorimetry showed that the material has thermal stability, in the temperature range ideal for application as a biomaterial, for example as biocuratives.

Made available in DSpace on 2020-12-10T17:34:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-08-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Biodiesel quality is dependent upon the fatty acids distribution of the raw material used in the trans/esterification reactions. While microalgae cells are regarded as potential oil suppliers for the biodiesel production chain, a common criticism is related to the low lipid productivities and often to a poor fatty acid distribution. In the present work we propose to submit microalgal cultivation to a second stage with nutritional stress by a simple addition of a 70% nitrate source depleted medium at the beginning of stationary phase, without harvesting cells, saving time and water. Chlorella minutissima was cultivated in a novel unconventional photobioreactor, named Internally Illuminated Integrated Photobioreactor (ILIPBR), to verify the efficiency of the proposed strategy. Biomass concentration, lipid content and volumetric lipids productivity increased 24.9%, 120.7% and 55.6%, respectively, from Stage 1 to Stage 2, when ILI-PBR was illuminated by constant blue LED and 0.5 vvm of aeration. The fatty acid profiles, evaluated in terms of LED illumination (white, red and blue), showed a predominance of palmitic acid in all cases (59.49%, 57.28% and 46.51%, respectively), which allowed to enhance some biodiesel properties such as cetane number, cold filter plugging point, density and kinematic viscosity, according to international specifications. (C) 2020 Elsevier Ltd. All rights reserved. Univ Sao Paulo, Engn Sch Lorena, Lorena, SP, Brazil Univ Fed Ouro Preto, Inst Exact & Biol Sci, Dept Chem, Lab Technol & Environm Chem, Ouro Preto, MG, Brazil Ctr Fed Educ Tecnol Celso Suckow Fonseca, Angra Dos Reis, RJ, Brazil Univ Fed Sao Joao del Rei, Alto Paraopeba Campus, Ouro Branco, MG, Brazil Univ Estadual Paulista, Engn Fac Guaratingueta, Guaratingueta, SP, Brazil Univ Estadual Paulista, Engn Fac Guaratingueta, Guaratingueta, SP, Brazil

Biopolymers are sustainable materials derived from renewable sources that have relevant and industrially attractive properties such as biodegradability, biocompatibility and antimicrobial effect. Thus, these were the target of several experimental studies, widely published in the literature and used in our daily lives. This paper presents a preliminary investigation on the polyesterification of a malic acid/glycerol mixture in order to obtain the poly(glycerol-co-malic acid) to be evaluated as a bioadhesive. For this, different reaction conditions were evaluated by varying the concentrations of malic acid, glycerol and zinc chloride(II) as catalyst, carried out according to the central composite rotatable design. The polymerizations were monitored by acidity index, hydroxamic acid test and conversion rate and the obtained materials characterized by FTIR. Poly(glycerol-co-malic acid) was obtained in yields of 38 to 68% which show that such method is promising for obtaining this new biopolymer aimed as bioadhesive.

The current competitive market demands that manufacturing companies have a survival strategy which should totally focus on providing high-quality products, being consistent in the level of service provided, having lower inventory levels and higher flexibility in operations. In this context, Kanban can be classified as a tool that assists in the proper sizing of inventory levels and production control of the system. However, numerous studies have been developed with the aim of reliably reducing stock levels in Kanban supermarkets, yielding different optimization techniques, but for fixed demands. This work proposes the minimization solution of the supermarket from randomly different demands, using environments with simulated experiments from the ARENA® software, from a response surface methodology (RSM) along with a weighted minimization of the mean standard error and compare with the results provided by the use of optimizer Arena OptQuest®, thus, it is possible to evaluate the robustness question.

The main objective of this study is the degradation of a synthetic solution of atrazine by a modified vermiculite catalyzed ozonation, in a rotating packed bed (RPB) reactor. A 0.5 L RPB reactor was used to perform the experiments, using a Central Composite Design (CCD) response surface to construct the quadratic model based on the factors: pH, catalyst concentration and reactor rotation frequency. The response variable was the removal of the organic load measured in terms of Chemical Oxygen Demand (COD). After the complete quadratic model was constructed through the response surface, the COD degradation process had an optimal removal of 41% under the following conditions: pH 8.0, rotation of 1150 rpm and catalyst concentration 0.66 g L

Several studies have focused in the tannery industry due to the high polluting potential of the effluent generated in leather processing; high concentrations of total chromium and organic load. However, the high costs attributed to the treatment of tanning residues explains why this material is not treated within the tannery industry. The extract from the flower of Musa sp, condensed and hydrolisable tanins, yet to be explored in literature was applied to remove organic matter from chemically enhanced primary treatment (CEPT) of total solids, turbidity and total chromium from a tanning industry and leather processing. The use of the flower extract of Musa sp. proposed in this study does not require flocculant polymers after the coagulation step. A central composite design response surface (CCD) was modelled by the factors: coagulant volume, pH and rotation. The optimization was performed according to the NBI algorithm in a mixed arrangement to determine optimal weights. The modeling from CCD and minimization of Global Standard Error determines the optimized conditions, turbidity removal, total cromium, hexavalent chromium and trivalente chromium of 78% and 65.4%, 39.43% and 61.02%, respectively, increasing the biodegradability from the ratio biochemical oxygen demand (COD) and chemical oxygen demand (COD) of 0.12–0.63.

One of the main problems that affects Ruhrstahl-Heraeus (RH) degasser circulation rate is the obstruction of the gas-injection nozzles. This study aims to elucidate the effects of obstructions in quantity and location using a physical model that depicts 16 injection nozzles on the up-leg distributed symmetrically in 2 rings (8 nozzles/ring). We simulated six, symmetric and nonsymmetric, obstruction conditions to gas flow. The gas-flow rate was varied from 30 to 130 NL/min. The results for symmetric obstructions when the gas-flow rate is kept constant, indicates that the circulation rate in the equipment does not significantly change. However, when these obstructions are non-symmetric, the circulation rate varies drastically, even when the gas-flow rate is kept constant. The analysis of the experimental data generated from this study allowed to determine an equation for the circulation rate that takes into consideration the number and distribution of blocked nozzles.

The search for a renewable source as an alternative to fossil fuels has driven the research on new sources of biomass for biofuels. An alternative source of biomass that has come to prominence is microalgae, photosynthetic micro-organisms capable of capturing atmospheric CO2 and accumulating high levels of lipids in their biomass, making them attractive as a raw material for biodiesel synthesis. Thus, various studies have been conducted in developing different types of photobioreactors for the cultivation of microalgae. Photobioreactors can be divided into two groups: open and closed. Open photobioreactors are more susceptible to contamination and bad weather, reducing biomass productivity. Closed photobioreactors allow greater control against contamination and bad weather and lead to higher rates of biomass production; they are widely used in research to improve new species and processes. Therefore, many configurations of closed photobioreactors have been developed over the years to increase productivity of microalgae biomass.

Made available in DSpace on 2021-06-25T11:22:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-10-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Microalgae have received special attention due to the biotechnological potential of their biomass, which can be used to produce biofuels, food formulations and pharmaceutical products. In order to improve biomass productivity, the present work proposes an internal light integrated photobioreactor (ILI-PBR), which integrates two configurations of photobioreactors (PBRs) already consecrated and widely used (tubular and bubble column) in a single system, combining the benefits of each configuration in a single PBR. To evaluate the applicability of ILI-PBR, a comparative test was conducted with the internal light bubble column photobioreactor (ILBC-PBR); both PBRs were illuminated with blue light-emitting diodes (LED).The PBR's performance was evaluated in terms of specific growth rate (mu(max)) and cell productivity (P-X) of the microalgae Chlorella minutissima. The mu(max) and P-X in ILI-PBR were at least 42.85 and 58.06 % higher than ILBC-PBR, respectively. ILI-PBR was 36 % more efficient in terms of electricity consumption than ILBC-PBR. Univ Fed Ouro Preto, Inst Exact & Biol Sci ICEB, Dept Chem, Lab Technol & Environm Chem, Campus Univ Morro Cruzeiro, Ouro Preto, Brazil Univ Sao Paulo, Sch Engn Lorena EEL USP, Lorena, SP, Brazil Ctr Fed Educ Tecnol Celso Suckow Fonseca CEFET R, Angra Dos Reis, RJ, Brazil Univ Fed Sao Joao del Rei UFSJ, Campus Ouro Branco, Ouro Branco, MG, Brazil Sao Paulo State Univ, Fac Engn Guaratingueta, Ave Doutor Ariberto Pereira da Cunha 333, BR-12516410 Guaratingueta, SP, Brazil Sao Paulo State Univ, Fac Engn Guaratingueta, Ave Doutor Ariberto Pereira da Cunha 333, BR-12516410 Guaratingueta, SP, Brazil

In the search for new solid fuels that can mitigate emissions of greenhouse gases and reduce municipal solid waste, it is proposed to produce a solid fuel from elephant grass charcoal (EGC) and blend it with the following binding recyclable materials, polyethylene terephthalate (PET) and high-density polyethylene (HDPE) with the aim of increasing their mechanical strength. Immediate analysis results indicate that there was an increase in volatile material content from 21.18% to 28.02% and a reduction in fixed carbon from 65.00% to 58.40% with the addition of binding agents. The higher heating value of pure charcoal was 5924.16 kcal/kg and there was no significant alteration by adding HDPE, however, with the addition of PET, there was an average reduction of 4.82%. According to the elemental analysis of charcoal, there were no significant amounts of sulphur, but silicon and potassium oxides were predominantly composed followed by aluminium, titanium, magnesium and iron according to the analysis of ashes. The addition of thermoplastic binders allowed producing pellets and it was found that those produced by using HDPE are stronger than those produced with PET.

This work studies low-cost coagulants and flocculants with satisfactory efficiency, using the flower from Musa sp. as raw material. Many coagulants already used in the market, have high application cost and they may also be polluters. The tannins, natural biocoagulants, coming from the secondary mechanism of plants, are somewhat chemically reactive and they have already been used in processes. The present work has the objective of obtaining tannins using hot percolation as the extraction method, with the following factors: extraction solvent type, batch extraction number and percolation time. To evaluate the best extraction condition, a response surface methodology characterized by a Central Composite Design (CCD) was used, which could analyze each of the respective factors in five levels. The optimization of the model generated from the response surface aiming at a higher concentration of tannins was done using the Generalized Reduced Gradient (GRG) algorithm. Under these conditions, the tannin concentration was 0.93 μg/mL in the experimental conditions defined by the following factors: acetic acid solution 12.5% v/v, 6 batch with 45 min each. Under these conditions, the efficiency of the extract in the coagulation and flocculation of sludge from the mining industry was 98.78% for turbidity removal and 99.24% for solid removal.

Tannins condensed and hydrolyzable, extracted from the flower of Musa sp. was used in the process of reducing turbidity of effluents from the processing of iron ore. A great deal of attention has been given to coagulation and flocculation processes in the separation of the ore fines that remain adhered to silica after processing, aiming at the reuse of process water and the iron itself with percentages between 15 and 35%. The coagulation and flocculation tests were performed in a jar test, verifying the influence of the factors: pH, coagulant volume and frequency of agitation aiming at turbidity reduction. Response surface methodology was used to construct a model and verify the influence of the levels of each of the factors on the turbidity reduction. From the constructed model, it was possible to optimize the turbidity removal through the generalized reduced gradient algorithm (GRG) leading to an initial turbidity reduction of 86500 NTU in 97.58%.

O presente trabalho consistiu na utilizacao do processo oxidativo avancado (POA) Foto-Fenton, para o tratamento de um efluente mimetizado de agua e gasolina comercial, de forma a simular aguas residuarias de postos de gasolina. Para tanto foi utilizado um reator tubular – Plug Flow Reactor (PFR) de tres modulos, sendo cada modulo concentrico, contendo em seu interior uma lâmpada de UV de 15 W encamisada em tubo de vidro de borosilicato de uma polegada de diâmetro. Foram coletadas 52 amostras de efluente sob diferentes condicoes de pH, concentracao de Fe2+ e peroxido de hidrogenio (H2O2) de forma a avaliar as possiveis interacoes entre essas variaveis e a porcentagem de carga orgânica removida do efluente. Dessa maneira, foi avaliada a relacao entre as variaveis pH, [Fe2+ ] e [H2O2], e sua influencia na remocao de demanda quimica de oxigenio (DQO). Os resultados obtidos demonstraram que as melhores condicoes para a realizacao do experimento foram: pH = 3, [H2O2] = 100 mM e [Fe2+] = 1,0 mM, condicoes essas que possibilitaram a maxima remocao de DQO alcancada neste estudo. The present work consisted in the use of the advanced oxidative process (AOP) Photo-Fenton for the treatment of a commercial water and gasoline effluent, in order to simulate wastewater from gas stations. A three - module plug flow reactor (PFR) was used, with each module being concentric, containing a 15 W UV lamp jacketed in a one - inch diameter borosilicate glass tube. A total of 52 effluent samples were collected under different pH, Fe 2+ and hydrogen peroxide (H 2 O 2 ) conditions, in order to evaluate the possible interactions between these variables and the percentage of organic matter removed from the effluent. In this way, the relationship between pH, [Fe 2+ ] and [H 2 O 2 ], and its influence on the removal of chemical oxygen demand (COD) were evaluated. The results showed that the best conditions for the experiment were: pH = 3, [H 2 O 2 ] = 100 mM and [Fe 2+ ] = 1.0 mM, conditions that allowed the maximum removal of COD reached in this study.

Optimized models of landfill leachate processes that could lead to the production of fuel oils from the pyrolysis of plastics and cultivation of microalgae, can be high-efficient and sustainable activities. Studies using advanced oxidation processes in combination with biological processes showed to be efficient in treating leachate. The complexity of this type of waste, as well as the continuous modification of its properties due to local seasonality, prevent kinetic and thermodynamic studies to predict the steady state at the final disposal. Environmental management system using Lean Six sigma accompanied with process modeling and optimization tools, whether statistical or computational, generate reliable models. These models can reproduce reductions on contaminants by confirming the initial conditions of each leachate enabling the scale-up of the process. This Review provides data survey, types of treatment and models linked to optimization tools in wastewater decontamination processes from municipal solid waste (MSW). This review includes the synthesis and proposal for treatment and management from of the classification of the garbage until the generation of leachate, aiming to contributing to future researches in the leachate treatment.

This paper presents the multiobjective optimization of methyl orange treatment with ozone using Normal Boundary Intersection and response surface models of rotated principal component factor scores for the expected value E[f(x)] and prediction variance Var[f(x)] of dye removal (Y 1 ) and chemical oxygen demand removal (Y 2 ). The innovation and the main contribution of this paper consists of building a 2-dimensional equispaced and convex Pareto Frontier for rotated factor scores representing the original multivariate set, reducing the number of objective functions without inverting the correlation among the original responses. Furthermore, this proposal provides a practical way to generate the narrowest possible prediction confidence intervals for a desired optima using the fuzzy membership function criterion in order to select the best compromise solution between E[f(x)] and Var[f(x)]. To illustrate the proposal's feasibility, a central composite design for the ozonation process of methyl orange solution with three factors (x 1 = pH, x 2 = air flow and x 3 = ozone dosage) was run. The optimization results showed a maximum dye removal of 94.1% ± 4.3 with a respective chemical oxygen demand removal of 88.4% ± 5.3 obtained at x* = [9.5; 7.1 l.min-1; 18.4 g h −1 ]. However, this point have presented the largest 95% prediction confidence interval. Based on the fuzzy membership of Pareto set it was possible to select the narrowest 95% confidence intervals with maximum removal rates (Y 1 = 90.5 ± 2.2 and Y 2 = 88.3 ± 2.7), obtained at x* = [7.9, 5.6 l min −1 , 18.4 g h −1 ]. Confirmation runs and comparisons among several optimization methods were done and indicated that the results fell within the respective confidence intervals for predictions, which corroborates the good adequacy of the proposal.

Pechini method was applied for the first time to synthesize CeNb3O9 perovskite at different calcination temperatures (600, 800 and 1000 °C). A solution of water, citric acid, ethylene glycol, ammonium niobium oxalate and cerium ions was polymerized and calcined at 300 °C for 2 h. The precursor gels were submitted to a second calcination at 600, 800 and 1000 °C to obtain perovskite at different temperatures. These materials were characterized through X-ray diffraction (XRD), thermogravimetric analysis (TGA), N2 physisorption, scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS), diffuse reflectance spectroscopy (DRS-UVvis) and Fourier transform infrared spectroscopy (FTIR). Results showed the formation of perovskite only at 1000 °C and Nb2O5-CeO2 mixed oxides at lower temperatures with some interesting characteristics. Pechini technique allows the synthesis of cerium niobate perovskite at lower temperatures than those presented in the literature (prepared by different methods).

The use of dispersed catalysts in aqueous medium inside reactors in advanced oxidative processes is common among researchers. However, due to the difficult separation of these species after treatment, in many cases, the treatment process is unfeasible. In this context, the main target of the work was the evaluation of degradation of the phenolic solution by ozonation titanium dioxide (TiO2/P25), supported on zeolite spheres. The process was investigated through the response surface methodology (RSM) and optimized by the generalized reduced gradient (GRG) algorithm. The effects of various operating parameters including pH, power ozone (O3) generation, flow rate, and treatment time were investigated, using as a response to removal of chemical oxygen demand (COD). It was made in optimum conditions the ratio of biochemical oxygen demand (BOD)/chemical oxygen demand to check the increasing biodegradability, aiming ozonation as preliminary treatment, with the possibility of subsequent biological treatments. There was an increase in this ratio from 0.17 to 0.50 in 48 min, which would facilitate the use of the subsequent biological process. The proposed model showed good fit to the experimental data with R2 and R2adj correlation coefficients of 0.9964 and 0.9932, respectively.

Conventional processes fail to improve the treatment of landfill leachate. Thus, the use of advanced molecular ozone oxidation processes combined with Rotating Packed Bed (RPB) reactor provides greater gas diffusion to the medium in a catalytic bed with vermiculite and it is a process likely to remove organic discharge. This study aimed to increasing the ratio between biochemical oxygen demand (BOD) and chemical oxygen demand (COD) as well as improving color removal through a modified vermiculite-catalyzed ozonation process in an RPB reactor. The factors of rotation of the bed in the reactor, initial pH and ozone flow were analyzed through experimental design represented by the central composite design (CCD) and later optimized through the Normal Boundary Intersection (NBI) algorithm. In the optimized operational conditions: rotation of 915 rpm, pH of 5.8 and ozone flow of 3.9 L min−1, the COD and color removal were 16.5% and 40.54%, respectively. An increase in biodegradability (BOD5/COD), from 0.13 to 0.49, under optimized conditions, demonstrated the efficiency of the process as a pretreatment of landfill leachate enabling further biological treatment.

Ozone and a Fe2+/TiO2-based catalyst were examined in the degradation of a synthetic solution of benzene toluene and xylene (BTX) in an advanced oxidation process (AOP). The catalyst beads were made from the slurry waste of aluminum production process, by inserting the TiO2 content and subsequent calcination. The reduction of the BTX concentration load was monitored by the reduction of chemical oxygen demand (COD) and BTX concentration. Different levels were used on factors: pH, time of treatment, initial concentration of BTX, and percentage of TiO2. The process was conducted in a bubble column reactor with the insertion of catalyst beads. A response surface methodology technique (CCD) was used to build a model based on COD reduction results. The model was optimized using the normal-boundary intersection (NBI) algorithm to maximize COD reduction and minimize the variance attributed to the process. Optimization led to COD reductions of 80% in 2 h of experiment. Correlation analysis of coefficient models from experimental data R2adj was 0.9966, showing a good fit of model data. In the optimized conditions, the possible increase of the biodegradability ratio of the BTX solution, through the biochemical oxygen demand (BOD) and COD, was also analyzed. Under pre-treatment conditions, the BOD/COD ratio was 0.13. After the treatment, it increased to 0.56.

The use of dispersed catalysts in aqueous medium inside reactors in advanced oxidative processes is common among researchers. However, due to the difficult separation of these species after treatment, in many cases, the treatment process is unfeasible. In this context, the main target of the work was the evaluation of degradation of the phenolic solution by ozonation titanium dioxide (TiO

Ozone and a Fe

RESUMO Foram estudados catalisadores a base de níquel (Ni) e cobre (Cu) suportados em Hbeta cuja atividade e seletividade foram avaliadas na reação de Hidrodesoxigenação (HDO) do benzaldeído. Para isso, sintetizaram-se catalisadores com 10,0 % de NiO (em massa) e adicionaram-se diferentes teores de CuO: 2,5 %, 5,0 %, 7,5 % e 10,0 % (em massa). Para efeito de comparação, foram sintetizados, também, os monometálicos NiO 10,0 % e CuO 10,0 % (em massa). A reação foi realizada em reator batelada com agitação magnética a 220 °C. Os catalisadores foram caracterizados pelas técnicas de difratometria de raios X (DRX), fisissorção de N2, redução com hidrogênio à temperatura programada (RTP-H2), espectroscopia por reflectância difusa nas regiões do ultravioleta e do visível (ERDUV-Vis) e análise termogravimétrica (TG/DTG). Pelos resultados de avaliação catalítica observou-se que o benzaldeído foi convertido em álcool benzílico, tolueno e benzeno. O catalisador Ni10Cu7,5/Hbeta apresentou conversão de 84,7 %, com seletividade para tolueno em torno de 91,0 %, apresentando maior seletividade a produtos desoxigenados que o catalisador com maior teor metálico (Ni10Cu10/Hbeta), fato que, possivelmente, possa estar associado à maior quantidade de sítios ácidos no catalisador. Os catalisadores bimetálicos apresentaram-se mais ativos que os monometálicos Ni e Cu. Dessa forma, a adição do Cu pode contribuir para a melhor performance dos catalisadores de Ni/Hbeta na reação de HDO. ABSTRACT The activity and selectivity evaluation of nickel (Ni) and copper (Cu) catalysts supported over Hbeta in the hydrodeoxygenation (HDO) reaction of benzaldehyde were studied. For this purpose, monometallic (10 wt.% of NiO or CuO) and bimetallic catalysts with 10 wt.% of NiO with different CuO (2.5 %, 5 %, 7.5 % and 10 % by wt.) were synthesized. The reaction was carried out in batch reactor with magnetic stirring at 220 °C. The catalysts were characterized by X-ray diffraction (XRD), N2 physisorption, hydrogen temperature programmed (TPR-H2), diffuse reflectance spectroscopy in ultraviolet and visible regions (DRSUV-Vis), thermogravimetric analysis (TG / DTG). Results of the catalytic evaluation showed that the benzaldehyde was converted to benzyl alcohol, toluene and benzene. Ni10Cu7.5/Hbeta catalyst presented a conversion of 84.73 %, with selectivity to toluene around 91 %, presenting higher selectivity to deoxygenated products than Ni10Cu10/Hbeta, which can be related to the higher acidic sites present in the catalyst. The bimetallic catalysts were more active than the monometallic Ni and Cu. Thus the addition of Cu can contribute to a better performance of the Ni/Hbeta catalysts in the HDO reaction.

Amoxicillin is a useful antibiotic to combat bacterial infections. However, this drug can cause serious problems when discarded in waterways due to its great bioaccumulation potential. This compound can be treated via advanced oxidation processes (AOPs), which are capable of converting amoxicillin into carbon dioxide and water. In this context, the use of ozone as an oxidizer has excelled in amoxicillin degradation. This paper aims at treating a synthetic solution of amoxicillin (0.1 g L−1) in a reactor with ozone bubbling. A Design of Experiment (DoE) with a response surface known as Central Composite Design (CCD) was used to optimize the treatment process. In addition, a Normal Boundary Intersection (NBI) method was used in the construction of a Pareto boundary chart. Results after 1-h treatment showed a reduction of 53% of the initial organic matter from a designed model using factors, such as pH, ozone generator power, and O3 flow. A model was built from the CCD with score of 0.9929. Thus, the model was able to represent the real scenario with confidence.

A glicerina loira, um coproduto obtido na produção do biodiesel pela reação de transesterificação, tem sido gerado na última década, em grandes quantidades cada vez maiores, devido ao aumento na produção desse biocombustível. Dessa forma, tornam-se importantes pesquisas relacionadas ao desenvolvimento de materiais e produtos que agreguem valor e destino ecologicamente adequado à esse resíduo. Nesse contexto, o presente estudo trata do reaproveitamento da glicerina loira na síntese de um biopolímero biodegradável, o poli(citrato de glicerol). As polimerizações foram estudadas empregando-se ácido cítrico/glicerina loira e ZnCl2 como catalisador. Obtiveram-se conversões de 58,2 % em 120 min de reação, usando-se a glicerina loira, sem tratamento prévio. Tais dados indicam a viabilidade do reuso da glicerina loira, sem pré-tratamentos, na preparação do respectivo biopolímero, um material com valor agregado e vantajoso ambientalmente.

Minimizing the variability of any process can become a way to reduce costs and at the same time keep the process stable. The use of the Normal Boundary Intersection (NBI) algorithm to construct the Pareto frontier can be applied to a better choice of a particular setup that can give the process a better response and less variability. The objective of this research is to propose the modelling and optimization for the maximum removal of the Chemical Oxygen Demand (COD) and the minimization of the variance associated the COD removal, to the UV/TiO2/O3 process, in the treatment of Eriochrome Black T. The factors studied in the COD removal were: pH, ozonator power, ozone flow and reaction time. The process of modelling used the response surface through the Central Compound Design (CCD) arrangement. In addition to the optimization, a Pareto Frontier using the NBI algorithm was utilized. The optimized results showed a COD removal of 33.7 ± 1.29 obtained X* = [7.7; 160 W; 5.6 L min−1; 22.6 min]. The confirmation of this point belonging to the Pareto frontier from the validation of the method was performed within a 95% confidence interval, the number of experiments being determined from the power sample size, comparing the ratio between the variances, weights w1 = 1 and w2 = 0.45.

RESUMO – Pelo trabalho avaliou-se a ativacao termica e quimica da lama vermelha, residuo do processo Bayer de obtencao de alumina, para ser usada como meio de reacao Fenton no tratamento de efluentes texteis. Da amostra recebida e seca, foram separadas aliquotas, as quais receberam tratamentos distintos, variando-se volume de solucao de H2O2, tempo de agitacao, temperatura de calcinacao e pH do meio. Apos sua ativacao, cada amostra foi empacotada em um tubo, formando uma coluna por onde percolou uma solucao de corante azul de metileno, analogo ao efluente textil. Verificou-se a eficiencia da remocao do corante atraves de analise em espectrofotometro de UV visivel da solucao contendo o corante antes e apos passar pela coluna de lama vermelha. Atraves dos resultados obtidos, determinou-se os valores de melhor eficiencia de remocao para cada umas das variaveis trabalhadas, demonstrando que o metodo e uma boa alternativa para o tratamento de efluentes texteis e aproveitamento da lama vermelha.

Advanced Oxidation Processes (AOP) have attracted much interest of scientific and industrial communities. Therefore, this process was employed experimentally to determine its efficacy in treating dairy effluents. For this, it was employed an artificial light reactor using photolysis (UV), hydrogen peroxide (H2O2) as an oxidant, and zinc oxide (ZnO) as an alternative catalyst. The variables studied in the photocatalysis were: H2O2, ZnO, under different values of pH, both in relation to the interferences with the reaction rate and with the process efficiency. First order differential equations were applied in determining the degradation rate over the hydraulic retention time (HRT); the F-test and the signal: noise ratio comparison were used to test the significance of variables. The AOP using photolysis UV, H2O2 and ZnO was effective in COD removal with 80% efficiency. As for the sterilization, in terms of total and fecal coliforms the efficiency was 100%, with the most probable number of total and fecal coliforms (MPN 100 mL -1 ) equal to zero. A catalyst/oxidant/pH ratio was observed at 1 g 30 mL -1 4 -1 for a better kinetic-chemical reaction, for 1 hour lighting.

Advanced Oxidation Processes (AOP) have attracted much interest of scientific and industrial communities. Therefore, this process was employed experimentally to determine its efficacy in treating dairy effluents. For this, it was employed an artificial light reactor using photolysis (UV), hydrogen peroxide (H2O2) as an oxidant, and zinc oxide (ZnO) as an alternative catalyst. The variables studied in the photocatalysis were: H2O2, ZnO, under different values of pH, both in relation to the interferences with the reaction rate and with the process efficiency. First order differential equations were applied in determining the degradation rate over the hydraulic retention time (HRT); the F-test and the signal: noise ratio comparison were used to test the significance of variables. The AOP using photolysis UV, H2O2 and ZnO was effective in COD removal with 80% efficiency. As for the sterilization, in terms of total and fecal coliforms the efficiency was 100%, with the most probable number of total and fecal coliforms (MPN 100 mL-1) equal to zero. A catalyst/oxidant/pH ratio was observed at 1 g 30 mL-1 4-1 for a better kinetic-chemical reaction, for 1 hour lighting.

Com o crescente número de indústrias pertinentes à área química, atrelada a grande quantidade de novos produtos, grande variedade de resíduos tem sido gerado diariamente. A maior parte do descarte dessas indústrias constitui-se de cargas muito poluentes e de difícil degradação, sendo em muitos casos incinerada. Resíduos desta classe, devido ao poder tóxico, devem como primeira etapa passar por um tratamento químico, visto que o tratamento biológico utiliza bactérias decompositoras as quais não suportariam o meio agressivo. Os processos muito utilizados hoje como tratamento químico são os processos oxidativos avançados (POAs), os quais podem ser utilizados de várias formas diferentes, sendo como caracteristica final a formação de radicais hidroxila. Desta forma, os processos heterogêneos têm recebido muito destaque na descontaminação de águas, principalmente industriais. Desta maneira, o presente trabalho teve como delineamento a construção e aplicação de um reator Counpound Parabolic Concentrator (CPC), para posterior tratamento de água de reação da produção de resina fenólica. Como fonte de radiação utilizada pelo reator, foi utilizada a própria radiação solar com o prematuro intuito de redução de custo do processo. Como fonte de radicais hidroxila, optou-se pelo uso de peróxido de hidrogênio, utilizando como catalisador o dióxido de titânio P25 Degussa. O reator teve como tempo de operação uma hora para cada batelada de 20 litros, onde amostras foram coletadas a cada dez minutos. As condições a serem avaliadas neste projeto, foram definidas de acordo com trabalhos previamente consultados pela literatura. A árvore de dados obtida pós-tratamento foi analisada segundo método de Taguchi utilizando assim uma matriz ortogonal com 16 experimentos, todos eles realizados em duplicata. Como variável resposta do processo foram analisadas a redução de Demanda Química de Oxigênio bem como o Carbono Orgânico Total. Entretanto para as condições dos fatores utilizadas neste trabalho, foi observada uma não redução satisfatória dos paramentros analisados, o que pode ser atribuído ao tempo para cada batelada atrelado a elevada carga orgânica inicial. With the growing number of industries relevant to the chemical area, linked to large amount of new products, great variety of waste has been generated daily. Most of the disposal of these industries is made up of loads very difficult to clean and degradation, and in many cases burned. Waste from this class, due to the toxic power, as a first step must go through a chemical treatment, since the biological treatment uses decomposing bacteria which can not handle the aggressive media. The processes commonly used today as chemical treatment are advanced oxidation processes (AOPs), which can be used in several different ways, as being characteristic final formation of hydroxyl radicals. Thus, the heterogeneous processes have received much emphasis on clean water, mainly industrial. Thus, this study was to design and implement the construction of a reactor Counpound Parabolic Concentrator (CPC) for further treatment of water from the reaction of phenolic resin production. As a source of radiation used by the reactor itself was used solar radiation with the early effort to reduce the cost of the process. As a source of hydroxyl radicals, we chose to use hydrogen peroxide, using as catalyst titanium dioxide Degussa P25. The reactor had the time of operation an hour for each batch of 20 liters, where samples were collected every ten minutes. The conditions to be evaluated in this project were defined in accordance with those previously found in the literature. The tree of data obtained after treatment was assessed by using Taguchi method as an orthogonal matrix with 16 experiments, all performed in duplicate. As response variable of the process were analyzed to reduce Chemical Oxygen Demand and Total Organic Carbon. However for the conditions of the factors used in this study, we observed no satisfactory reduction of paramentros analyzed, which can be attributed to the time for each batch tied to high organic load stage.

A busca por uma fonte de matéria prima renovável alternativa aos combustíveis fósseis tem impulsionado o desenvolvimento de novas fontes de biomassa para os biocombustíveis. Uma fonte de biomassa alternativa que vêm ganhando destaque são as microalgas, microorganismos fotossintéticos capazes de capturar o CO2 atmosférico e acumular altos teores de lipídeos em sua biomassa, tornando-os muito atrativos como matéria-prima para a síntese de biodiesel. Nesse sentido, muitos trabalhos têm sidos conduzidos para o desenvolvimento dos mais variados tipos de fotobiorreatores para o cultivo de microalgas. Assim, o presente trabalho propôs um fotobiorreator integrado (coluna de bolhas e tubular), internamente iluminado com luz de LED, para estudar os efeitos dos fatores: cor da iluminação, fotoperíodo, aeração e vazão de circulação de meio, no cultivo foto-autotrófico da microalga marinha Chlorella minutissima em duas fases, utilizando o planejamento estatístico de Taguchi (L9), com vistas à formação de biomassa e ao acúmulo de lipídeos nessa microalga, para a produção de biodiesel. Foi alcançada a máxima concentração de biomassa de 506 mg L -1 e a máxima produtividade volumétrica de biomassa de 62,5 mg L -1 com 20,2 % de lipídeos para o cultivo da Chlorella minutissima no fotobiorreator integrado internamente iluminado com a cor azul, em fotoperíodo de 24 h diárias de iluminação, provido com 0,5 vvm de aeração e 5,1 L min -1 de vazão de recirculação de meio de cultivo. O perfil dos ácidos graxos presentes no extrato lipídico da Chlorella minutissima apresentou predominância de ácidos graxos saturados, com destaque para o ácido palmítico (C 16 : 0), com 59,49 %, 57,28 % e 46,5 %, nos cultivos iluminados com as cores, branco, vermelho e azul, respectivamente. A partir dos lipídeos extraídos, atingiu-se 96,6 % de conversão em biodiesel utilizando etanol via catálise ácida com ácido sulfúrico (10 % m / m) durante 8 h de reação à 80 ?C. The search for a renewable source alternative to fossil fuels has driven the development of new sources of biomass for biofuels. An alternative source of biomass that have come to prominence are microalgae, photosynthetic micro-organisms capable of capturing atmospheric CO2 and accumulating high levels of lipids in their biomass, making them very attractive as a raw material for biodiesel synthesis. In this way, many studies have been conducted for the development of the many types of photobioreactors for the cultivation of microalgae. Thus, the present work proposed an integrated photobioreactor (bubble and tubular column), internally illuminated with LED light, to study the effects of the factors: illumination color, photoperiod, aeration and culture medium recirculation flow rate, in photo-autotrophic cultivation of the Chlorella minutissima, in two phases, using design of the experiment (Taguchi - L9), aiming the biomass production and lipid accumulation, for the biodiesel production. The maximum biomass concentration of 506 mg L -1 and the maximum biomass volumetric productivity of 62.5 mg L-1 with 20.2% of lipids were obtained with the cultivation of Chlorella minutissima in the integrated photobioreactor internally with blue illumination, 24h of photoperiod, 0.5 vvm of aeration and 5.1 L min -1 of culture medium recirculation flow rate. The fatty acids profile present in the lipid extract of Chlorella minutissima showed a predominance of saturated fatty acids, with emphasis on palmitic acid (C 16: 0), with 59.49%, 57.28% and 46.5%, to cultivations illuminated with white, red and blue, respectively. From the extracted lipids, 96.6% were converted in biodiesel via acid catalysis using ethanol with sulfuric acid (10% w / w) for 8 h of reaction at 80 ° C.