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In the photo-chemical conversion of hydrogen peroxide (H2O2) into radical ⦁OH, the impact of radiation dose (the quantum yield) on the oxidation kinetics has been properly reported, whereas the H2O2 dose is mostly treated as an attempt-and-error variable. This present work formally analyses the oxidant dose in terms of the efficiency of ⦁OH consumption by the micropollutant mineralization, which ultimately enables a generalist strategy for more cost-effective dosimetry of the oxidant. The experimental time-dependent measure of two reagents (pollutant and oxidant) and one product (CO2) enables assessment to the micro-kinetics from the perspective of the chemical dynamic. The analysis was demonstrated for photo-Fenton (FP) oxidation of hydrochlorothiazide (HCT) using a tubular photo-reactor and UVA radiation. The average value of ~ 38% was on top of the best efficiencies in association with some of the fastest rates of mineralization. Such efficiencies are demonstrated to depend on the stochiometric concentration of the oxidant. Here, the variable stoichiometric H2O2 excess for mineralization is proposed as a universal metric to quantify the (under-) over-dose of H2O2. Overall, H2O2 excess between 2 and 5 leads to H2O2 consumption efficiencies above 30% together with a fast rate of CO2 formation (mineralization), whereas any value below 1 invariably leads to a sluggish oxidation rate, leading even to the full depletion of the oxidant. Aside from proposing a selection criterion for the most cost-effective H2O2-dose and providing some examples, this work carefully analyzes the commitment of the H2O2 excess with respect to the energy costs (EEO).

Produced water, a mixture of inorganic and organic components, comprises the largest effluent stream from oil and gas activities. The removal of contaminants from this wastewater is receiving special attention of the researchers since most of them are persistent and difficult to remove with simple techniques. Several technologies from conventional to advanced oxidation processes have been employed to treat produced water. However, the achievement of greater efficiency may be conditioned to a combination of different wastewater treatment techniques. Hereupon, the present paper discusses three important aspects regarding produced water treatment: analytical methods used for characterization, relevant aspects regarding photochemical systems used for advanced oxidation processes, and combined techniques for treating oil field wastewaters. Analytical methods employed for the quantification of the main species contained in produced water are presented for a proper characterization. Photochemical aspects of the reaction systems such as operating conditions, types of irradiation sources, and technical details of reactors are also addressed. Finally, research papers concerning combined treatment techniques are discussed focusing on the essential contributions. Thus, this manuscript aims to assist in the development of novel techniques and the improvement of produced water treatment to obtain a high-quality treated effluent and reduce environmental impacts.

2030-12 The presence of toxic chlorinated compounds in drinking water, generated during the disinfection step in water treatment plants, is of great concern for public health. In the present study, the performance of the UVC/H2O2 process, preceded by zero-valent-copper reduction, was evaluated for degrading 2,4,6-trichlorophenol (TCP). With this aim, the oxidation performed alone or in combination with the pre-reductive step was evaluated regarding TCP concentration over time, removal rate, mineralization, and toxicity to Vibrio fischeri, as well as oxidant dosage and the effect of water matrix. The UV/H2O2 process achieved fast (kobs = 1.4 min-1) and complete TCP degradation, as well as important mineralization (40.4%), with best results obtained for initial H2O2 concentration of 0.056 mmol L–1. Coupling of reductive and oxidative processes intensified contaminant mineralization, due to the synergistic effect of copper ions leached in the reductive process, particularly Cu(I), providing an additional route of H2O2 activation for generating HO• radicals (photo-Fenton-like process). High toxicity removals and increased mineralization could be successfully accomplished by the combined processes even in tap water, which is a clear advantage for practical application

Distillation columns are important separation equipment that comprise most of the investment needed in a petroleum refining plant. Utilities and energy demands, though, are a concerning factor in the current economic and environmental scenario. The present work proposes a methodology to optimize the energy consumption of a crude oil distillation column using the Distop Calibration technique that allows faster convergence than the Tray-to-Tray method. The methodology presented involves process simulation, sensitivity analysis, factorial design, and the use of response surface methodology. Results show that it is possible to achieve significant gains by changing feed temperature and rectifying vapor flow, causing a relevant reduction in energy consumption. Hence, the methodology can be used as an optimization tool to increase energetic efficiency.

Hydrochlorothiazide (HCT) is a pharmaceutical micropollutant highly toxic to the environment, being absolutely necessary to oxidize it completely to CO

The present work had the objective to study oxygen carriers (OCs) in Chemical Looping Combustion (CLC) using ethanol as fuel. Copper-based OCs in different mass concentrations and addition of 1% cerium were evaluated for their reactivity, as well as the kinetics process, applying the shrinking core and nucleation models to obtain the kinetic constants. A thermodynamic study, regarding equilibrium constant, was also carried out. The results showed that all Cu-based OCs reached maximum conversion, showing to be quite reactive, and well described by the nucleation model. It was also verified that a lower content of metallic oxide, promotes a higher rate of reaction. Regarding the CuO/Cu redox system, it was observed that high values of the equilibrium constant (Keq) were obtained in the investigated temperatures, showing that an almost complete conversion of the fuels, is possible.

The production of oil and gas is usually accompanied by the production of waste water, which contains several organic pollutants. The objective of this work is to investigate the removal of organic load from synthetic oilfield produced water by adsorption process, using activated carbons from vegetable and animal origin. The synthetic oilfield produced water was constituted by a mixture of xylene, n–heptane, phenol, and NaCl in aqueous solution. The structural properties of the samples were investigated by X–ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N2 adsorption–desorption isotherms, and scanning electron microscopy (SEM). Effects of temperature and type of adsorbent on the adsorption process were investigated. According to the results, the temperature of 25 °C was more favorable in adsorption of organic load from synthetic oilfield produced water. Pseudo–first order, pseudo–second order, and Elovich equations were able to represent the adsorption kinetics. The vegetable activated carbon delivered the best results, being the most efficient to remove the organic load due its high surface area. The adsorption capacities were 28 and 15 mgTOC g–1, for vegetable and animal activated carbons, respectively.

Monoethylene glycol (MEG) is a gas hydrate inhibitor widely applied for natural gas flow assurance. A series of density and electrical conductivity measurements of water + MEG + NaCl mixtures are reported, allowing the supervision of the MEG regeneration unit. Density (509 data points) and electrical conductivity (212 data points) measurements were performed in wide ranges of temperature, T = 278.15−363.15 K, and concentration of solvents and NaCl up to almost saturation. The theory of solutions was applied for density description using excess volume, which was correlated with the Redlich−Kister equation. The resulting absolute and relative mean deviations are 0.00127 g·cm−3 and 0.12%, indicating accurate representation. A semi- empirical correlation with 15 adjustable parameters was considered for electrical conductivity of water + MEG + NaCl mixtures. The obtained absolute and relative mean deviations are 1.49 mS·cm−1 and 5.70%. The properties functions presented an approximately orthogonal behavior to each other, allowing the determination of mixture composition from experimental density and electrical conductivity data. The Matlab environment was found to be robust in solving the nonlinear system of two equations with constraints. The proposed methodology was extensively tested, and deviations less than 0.0060 and 0.0011 in solvents and NaCl mass fractions were obtained, respectively, demonstrating the required accuracy for industrial application

Produced water, a mixture of inorganic and organic components, comprises the largest effluent stream from oil and gas activities. The removal of contaminants from this wastewater is receiving special attention of the researchers since most of them are persistent and difficult to remove with simple techniques. Several technologies from conventional to advanced oxidation processes have been employed to treat produced water. However, the achievement of greater efficiency may be conditioned to a combination of different wastewater treatment techniques. Hereupon, the present paper discusses three important aspects regarding produced water treatment: analytical methods used for characterization, relevant aspects regarding photochemical systems used for advanced oxidation processes, and combined techniques for treating oil field wastewaters. Analytical methods employed for the quantification of the main species contained in produced water are presented for a proper characterization. Photochemical aspects of the reaction systems such as operating conditions, types of irradiation sources, and technical details of reactors are also addressed. Finally, research papers concerning combined treatment techniques are discussed focusing on the essential contributions. Thus, this manuscript aims to assist in the development of novel techniques and the improvement of produced water treatment to obtain a high-quality treated effluent and reduce environmental impacts.

2030-12 Monoethylene glycol (MEG) is used to prevent hydrate formation in subsea pipelines of natural gas production. MEG is recovered at an offshore regeneration unit. Sodium chloride is the predominant salt in the water−MEG streams. Thus, knowledge of NaCl solubilities in the process conditions is relevant for the design and operation of a MEG regeneration unit. Six isotherms of NaCl solubility were measured (76 data points) from T = (293.15 to 403.15) K in the whole solvent concentration range. The analytical method for salt solubility was based on the reproducibility of the concentration of two successive samples. Density measurements were accurately applied for these analyses. The temperature dependence on NaCl solubility is relatively weak. A reverse behavior with increasing temperature was observed for MEG contents higher than 90 wt %. Salt solubilities were successfully correlated with Redlich−Kister expansion (AADwNaCl = 0.0006 and ΔwNaCl = 0.47%). Electrical conductivity of NaCl - saturated solutions were measured (44 data points) at T = (293.15 to 363.15) K and correlated with a semiempirical model. A large difference in electrical conductivity for the two solvents was observed. The correlation adequately represented the data set (AADκ = 5.67 mS·cm−1 and Δκ = 5.94%). NaCl solubilities and electrical conductivities were accurately determined and are useful for the MEG regeneration process

Hydrochlorothiazide (HCT) is a pharmaceutical micropollutant highly toxic to the environment, being strictly mandatory to oxidize it completely toward CO2. In this context, how could the HCT oxidation via advanced oxidative processes benefit from the accelerated oxidation rates promoted by the mineralization stoichiometric excess of H2O2 ? Overall, this work elucidates the role of stoichiometric H2O2 concentration on promoting fast degradation/mineralization rates across Advanced Oxidative Processes (AOP). Employing 0.68 excess of H2O2, it was found absolute (100%) HCT degradation within 60 minutes and 95% within 30 min for UVC-H2O2 oxidation; however, the mineralization of HCT suffered limited optimization even at high H2O2 excess, being at the best performance 26.76% HCT mineralized via UVC photo-Fenton within 60 min at initial 2.00 H2O2 excess. Very presumably, the evaporation of H2O2 was the underlying reason for a low mineralization performance. Together with a detailed mathematical methodology, the time-synchronized evolution of both the residual H2O2 concentration and the TOC depletion were employed to infer the quantity of radical ∙OH that effectively was consumed by the micropollutant mineralization. The global mean efficiency of radicals •OH consumption by the HCT mineralization laid around 15% for UVC Fenton considering H2O2 excess of 2.00. Under these conditions, the residual H2O2 concentration depletes significantly within 30 minutes of UVC photo-Fenton oxidation, which indicates that either the solution heating or stirring is very likely to promote a substantial loss of H2O2 by evaporation in the beaker-assembled reactor

2030-12-30 Vapor−liquid equilibrium (VLE) data for aqueous systems in the presence of electrolytes have many industrial applications. VLE data for water + monoethylene glycol (MEG) mixtures in the presence of sodium chloride at low pressures are important to describe the effects of composition, temperature, and pressure on a MEG (gas hydrate inhibitor) regeneration unit. A modified version of the Othmer ebulliometer was applied to measure reliable VLE data for water + MEG + NaCl at 101.325, 65, and 35 kPa. Binary systems (water + MEG and MEG + NaCl) were also experimentally studied. Vapor pressures for water and MEG were determined and compared with the selected literature data via Antoine correlation. The electrolyte nonrandom two-liquid and universal quasi-chemical activity coefficient models were successfully parameterized to describe the VLE behavior for water + MEG + NaCl systems. Thermodynamic consistence of the data sets was also checked. Interaction parameter estimation followed a systematic strategy: (1) water−MEG, (2) water−NaCl, and finally (3) MEG−NaCl with the experimental data of MEG + NaCl and ternary data. MEG + NaCl solutions presented an inverted colligative property, that is, the addition of salt decreases the boiling point. VLE data indicated that water separation is less efficient due to the addition of salt. The parameterized models allow an evaluation of the MEG regeneration process as a function of temperature, pressure, and composition

2030-12 Creosote is a multicomponent oil classified as a dense non-aqueous phase liquid (DNAPL) produced from coal tar distillation. The concept of phase distribution is critical in decision-making to remediate contaminated sites. The creosote mass transfer between sorbed, aqueous, vapor, and DNAPL phases is controlled by physicochemical characteristics, geology of the site, and environment conditions. This study evaluated phase distribution of the main polycyclic aromatic hydrocarbons (PAHs) of creosote in a sandy soil with low organic matter content. The creosote was collected from a contaminated site in São Paulo, Brazil, and was characterized by gas chromatography–mass spectrometry (GC-MS). Clean soil was collected upgradient from the same area. Initially, the soil was artificially contaminated with creosote. After, the contaminated soil was put in contact with clean water in sealed vials for 72 h. Samples of the soil, vapor, and liquid phases were collected and analyzed by GC-MS. In total, 50 compounds were identified in the creosote, and 9 PAHs were selected to be studied, which represented around 30% of total creosote mass. The major contaminant concentration was detected in the sorbed phase. For instance, naphthalene mass was distributed in sorbed (33.0%), DNAPL (1.5%), aqueous (3.4%), and vapor (0.2%) phases. The results provided an understanding of the contaminant species partitioning that occurs in a real contaminated site

The presence of toxic chlorinated compounds in drinking water, generated during the disinfection step in water treatment plants, is of great concern for public health. In the present study, the performance of the UVC/H

Hydrocarbon contaminated sites are a critical issue. Soil is a complex substrate and its heterogeneity makes soil remediation a difficult task. Studies involving in situ chemical oxidation focusing on soil remediation are scarce in literature. Heterogeneous catalysts for oxidation process can be supported in clays. In this work, different clay-based catalysts were synthesized. Concentrations of sodium hydroxide (NaOH), ferrous sulfate (FeSO4), and ferric sulfate (Fe3(SO4)2) were varied in accordance with a 23 experimental design. Modified clay catalysts (MCC) were applied in oxidation assays of phenanthrene (PHE) contaminated soil to evaluate the activation of two oxidants: sodium persulfate (SP) and hydrogen peroxide (HP). The experimental design response was the PHE removal. Most of the catalysts proved to be efficient in activating both oxidants and achieved around 80 % of PHE removal. Control assays showed that around 20 % of PHE can be naturally transferred from soil to the liquid phase. PHE removal did not occur during oxidation with raw clay (RC). The highest PHE removal was obtained using MCC 16 with HP, reaching 83 %. XRF analysis of MCC 16 indicated an increase of 160 % in iron content and the Mossbauer spectroscopy showed higher values of relative Fe3+ doublet area for MCC 16 than for RC. BET surface area measurements and scanning electron microscopy analysis suggested the impregnation of iron minerals on the MCC 16 surface. The catalyst proposed in this study can be applied in both in situ or ex situ remediation circumstances, reducing the environmental effects of organic contaminants.

Chemical oxidation was applied to an artificially contaminated soil with naphthalene (NAP). Evaluation of NAP distribution and mass reduction in soil, water and air phases was carried out through mass balance. Evaluation of NAP distribution and mass reduction in soil, water and air phases was carried out through mass balance. The importance of the air phase analysis was emphasized by demonstrating how NAP behaves in a sealed system over a 4 hr reaction period. Design of Experiments method was applied to the following variables: sodium persulfate concentration [SP], ferrous sulfate concentration [FeSO4], and pH. The system operated with a prefixed solid to liquid ratio of 1:2. The following conditions resulted in optimum NAP removal [SP] = 18.37 g/L, [FeSO4] = 4.25 g/L and pH = 3.00. At the end of the 4 hr reaction, 62% of NAP was degraded. In the soil phase, the chemical oxidation reduced the NAP concentration thus achieving levels which comply with Brazilian and USA environmental legislations. Besides the NAP partitioning view, the monitoring of each phase allowed the variabilities assessment over the process, refining the knowledge of mass reduction. Based on NAP distribution in the system, this study demonstrates the importance of evaluating the presence of semi-volatile and volatile organic compounds in the air phase during remediation, so that there is greater control of the system as to the distribution and presence of the contaminant in the environment. The results highlight the importance of treating the contaminant in all its phases at the contaminated site.

2030 BACKGROUND Over recent years, several studies exploring new technologies capable of degrading persistent organochlorine compounds have been published. Special attention has been dedicated to atrazine (ATZ), due to its ecotoxicological relevance together with its frequent detection in the environment. Degradation of organochlorines via zero-valent metals has gained great importance given its practicality and versatility, zero-valent-iron (ZVI) being the most applied metal for this purpose. Alternatively, zero-valent-copper (ZVCu) was proved to exhibit higher reactivity against chlorinated aromatics, therefore deserving further investigation. RESULTS The optimum degradation conditions for ATZ removal with ZVCu were explored through a Doehlert experimental design. The same conditions were tested for the traditional ZVI, which confirmed that ZVCu was more reactive. The analysis of the degradation products suggests that both reductive and oxidative pathways coexist in the studied process. CONCLUSIONS ZVCu was effective in ATZ degradation, both by reductive and oxidation pathways, within a wide range of pH values, although faster in acidic media. The resulting solution from the experiment that promoted the fastest degradation is less toxic than ATZ against microalgae Chlorella vulgaris, which is a positive output regarding the application of this process as a pre-treatment step of ATZ-contaminated water matrices. © 2018 Society of Chemical Industry

In general, the oil industry has been searching for ways to alleviate the abundant disposal of oilfield produced water, which contains dissolved hard-removal and highly toxic organic compounds. Advanced oxidative processes (AOPs) have revealed to be effective in the degradation of organic compounds, because they generate hydroxyl radicals with high oxidizing potential which are capable of degrading these compounds. The present study has demonstrated the degradation efficiency of effluents containing organic compounds although the photo-Fenton process using a tubular photochemical reactor under different energy sources. This reactor allowed the use and evaluation of two ultraviolet irradiation sources, the sun and black light lamps, besides other relevant variables to the process, such as reagents concentration and the irradiated area, using a model effluent containing phenol. A sample of oilfield produced water was photochemically degraded through the optimum experimental conditions found for the phenol degradation. Solar irradiation was more efficient than lamplight, and it corresponds an important factor for the reduction of operating costs of this process. The solar reaction system applied to the oilfield produced water showed a removal of organic components up to 76%

The oil reservoirs are underground and have the oil and gas contained in the porous rock at high temperatures and pressures. Only 5–20% of the oil is withdrawn in primary production. Further recovery can be achieved by injecting carbon dioxide (CO2) that displaces and dissolves part of the remaining oil; this process is called enhanced oil recovery. Although the characterization and fractionation of petroleum are well-known and studied, each oil sample represents a unique multicomponent system; therefore, an individual study of the sample is required. Real samples of condensate gas (CG) and light crude oil (LCO) were collected and analyzed for density, viscosity, atmospheric distillation and fractionation, and aiming characterization. Synthetic visual and non-visual methods for high pressure were successfully applied for bubble point measurements of the systems composed of supercritical CO2 and CG or LCO. Phase envelope calculations were developed on the basis of pseudo-components obtained by atmospheric ...

Ampicillin belongs to the class of beta-lactam antibiotics, which corresponds the most prescribed antibiotics in medicine. This justifies the importance of elucidating the effect of several variables for the synthesis process (pH, temperature, co-solvent) on the behavior of the compounds involved in the enzymatic reaction. This paper aims to present new ampicillin solubility data in aqueous medium and the characterization of the solid phase of the antibiotic. In the phase equilibrium experiments it was considered the effect of pH (3 up to 7.5), temperature (283.15 K up to 298.15 K) and the ethanol concentration in the aqueous solution (varying between 0 and 70 wt% ethanol). The solubility curves deviate from U-shape solubility curves with respect to pH in the range of 0e70 wt%. This is due to ampicillin anhydrous becomes trihydrated molecule in the solid phase at alkaline pH region, changing the antibiotic properties significantly. This change in crystalline structure was confirmed by characterization of antibiotic solid phase carried out from thermogravimetric (TGA), Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) analyses. Dissociation constants have also been measured at the studied values of temperature and ethanol composition, using potentiometric titration. Finally, a thermodynamic model considering the ideal solution was applied to describe mathematically the solubility curves measured close to experimental uncertainties

Monoethylene glycol (MEG) is used as hydrate inhibitor in natural gas exploitation. During the process, MEG mixed with produced water and salts must be regenerated. Therefore, salt solubility and physicochemical properties of MEG aqueous mixture with electrolytes are useful to operate the regeneration unit. This work determines density and electrical conductivity data at 298.15 K for water+MEG+CaCl2 systems. The density data were correlated applying the excess volume approach and Redlich Kister expansion, resulting absolute and relative mean deviations of 3 × 10–4 g‧cm–3 and 0.028%. For electrical conductivity correlation a semiempirical model was applied resulting absolute and relative mean deviations of 1.27 mS‧cm–1 and 3.53%. CaCl2 solubilities in water-MEG mixtures at 298.15 and 323.15 K were also measured. The proposed analytical method used precise density measurements to determine salt solubility. Moreover, the solid phase composition was determined by thermogravimetry analysis. Four different solid phases were identified as function of the solvent composition. At 298.15 K the addition of MEG changed the solid phase from CaCl2•4H2O to CaCl2•3H2O•MEG for w’MEG ≥0.36. Regarding 323.15 K, solid phase changed from CaCl2•2H2O to CaCl2•H2O•MEG for w’MEG≥0.30. Density, electrical conductivities and CaCl2 solubilities were accurately determined and are of interest to the natural gas industry.

Fructose (1,3,4,5,6-pentahydoxyhex-2-one) is an important sugar in the global market because of its unique characteristics when compared to other sugars, which makes fructose economically attractive, even though it is not easily produced. Crystalline fructose may be produced by crystallization of its aqueous solution, with the addition of ethanol as anti-solvent. After the separation of the crystals, the recovery of (ethanol + water + fructose) mother-liquor becomes feasible. Then, a distillation step may recover ethanol, and vapour-liquid equilibrium (VLE) data for (water + ethanol + fructose) mixtures are consequently necessary, despite not being available in the literature. In this work, VLE results for (water + ethanol) and (water + ethanol + fructose) were determined using a modified ebulliometer based on vapour recirculation. VLE measurements for (water + ethanol) were used to verify the thermodynamic consistency applying the Global Area Test developed by Redlich-Kister-Herington. Group contribution activity coefficient models were selected and evaluated to predict VLE for the ternary system. S-UNIFAC, A-UNIFAC and mS-UNIFAC models were tested. mS-UNIFAC demonstrated the best results, with average absolute relative deviation between experimental data and values calculated from the model of 0.1%, 3.6%, 3.0% and 3.6% for mole fraction of ethanol vapour when 0, 10.3, 20.7 and 31.0 mass percent of fructose were used.

Durante a extração do petróleo ocorre a produção de uma corrente aquosa denominada água de produção de petróleo. Este efluente contém compostos orgânicos e inorgânicos de alta periculosidade, e seu destino tem sido um desafio para a indústria petrolífera. Dessa forma, esta pesquisa propõe uma alternativa para a inertização desses compostos através do processo de Flotação por Ar Induzido (FAI), esta operação unitária apresenta simplicidade, alta eficiência na remoção de contaminantes, capacidade para médias e altas vazões, baixo custo operacional e tempo de residência curto, o que implica em menores espaços e economia na construção. Para avaliar este método, foram analisados os teores de carbono orgânico (TOC) e inorgânico (IC) para a água produzida e industrial, de modo a observar a quantidade de contaminante ao longo do processo Inertization process of the oil drilling waste through the Flotation by Induced Air process During the oil extraction occurs the production of an watery current named water produced. This effluent contains highly dangerous organic and inorganic compounds, and its destiny has been a challenge to the oil and gas industry. In this way, this research suggests an alternative to the inertization of these compounds through the Flotation by Induced Air (FIA) process. The device shows simplicity, high efficiency of the removal of contaminants, capacity for medium and high flows, low operational cost and short residence length, which implies in lower spaces and the economy in construction. To evaluate this method, were analyzed the organic and inorganic carbon contents to the industrial and produced water, with the aim to observe the quantity of contaminants during the process

Growing interest in the study of production conditions in the presalt led to the need to study complex systems at high pressures and temperatures, such as up to 70 MPa and up to 393 K. The aim of this work is to obtain vapor–liquid equilibrium data at high pressures and temperatures for hydrocarbon systems with carbon dioxide (CO2). To obtain these data, an experimental setup and procedure using a synthetic cell were designed. Experimental data of the binary system CO2 + cyclohexene (C6H10) and CO2 + squalane (C30H62) over a range of temperature between 303 and 398 K and the ternary system CO2 + C6H10 + C30H62 at various temperatures (318–393 K) and compositions are reported. It is noteworthy that the reported measurements in this work were not studied in the literature, and experimental data may contribute to industrial and scientific interests. The phase behavior of the system was also described using the Soave–Redlich–Kwong equation of state together with Mathias–Copeman alpha function. Interaction par...

2030-12 Emerging pollutants have been the subject of worldwide study because their continuous entry into the environment presents a risk to ecosystems and human health. Advanced oxidation processes show promise for eliminating or reducing the concentrations of emerging pollutants in water. This study aimed to investigate the treatment of aqueous systems containing the synthetic hormone 17α-ethinylestradiol. An innovative method for persulfate activation catalysed by ironmodified diatomite (heterogeneous system) was compared to conventional homogeneous activation methods (iron activation, alkaline activation, and heat activation). Iron-modified diatomite was more efficient in activating persulfate than traditional processes, achieving 98% of pollutant removal. Experimental results indicated that the catalyst can be reused without loss of removal efficiency, with potential environmental and economic benefits

This work aimed to study nickel-based oxygen carriers (OC) for Chemical Looping Combustion (CLC) using H2 and CH4 as fuel. The reactivity and reaction kinetics of the OC were investigated, applying the shrinking core, nucleation and diffusion models in three dimensions, as well as whether the OC is thermodynamically favorable for the reaction. The results showed that the OC achieved high conversion for both fuels, proving to be quite reactive, while the fuel gas concentration and the temperature have a strong effect on the solids conversion. For the H2 combustion, the reaction rate can be described well by the shrinking core model, whereas for CH4 the nucleation model may better represent the experimental data. With respect to reactions that occur in the reduction reactor with the NiO/Ni redox system, it was observed that, for the investigated temperatures used in CLC, high values of the equilibrium constant were obtained, showing that practically complete conversion of the fuels is possible.

The presence of toxic chlorinated compounds in drinking water, generated during the disinfection step in water treatment plants is of great concern for public health. Therefore, special attention has been given to the development of effective organochlorine-removal techniques. The reductive degradation via zero-valent-metals is recognized as a promising alternative. In this study, the capacity of zero-valent-copper (ZVC) containing materials to degrade 2,4,6-thichlorophenol (TCP) was investigated, using a bench-scale recirculating packed column system. The results indicate that this metal is effective for TCP degradation and dechlorination, even when derived from scrap. The kinetic model that better suits the degradation profiles is a second-order model, with an average normalized surface area rate constant (kSA’) of (2.44 ± 1.27) × 10−3 L² min−1 m−2 for ZVC-containing materials. The ZVC scrap-derived material was found attractive for field applications due to its reusability and low leachability, despite its performance being affected in the presence of water natural constituents. The degradation by-products elucidated confirm that dechlorination is the main degradation pathway, leading to the formation of totally dechlorinated by-products such as phenol-like compounds and cyclohexanone. However, these may still pose a threat to aquatic organisms as revealed by toxicity assays and activity-structure relationship model (ECOSAR USEPA) predictions. Further investigation is therefore required aiming at following by-products formation with degradation time in order to find the best residence time that generates innocuous and/or adequate effluents for environmental disposal.

2030-12-30 In order to represent the thermal effects of the operational conditions of a monoethylene glycol (MEG) regeneration unit, 86 wt % MEG aqueous solutions with salt concentrations up to 5.52 wt % were heated for 56 h in an ebulliometer. Seven analytical techniques were applied to the samples, aiming to evaluate MEG degradation. Results demonstrated that increasing the sodium chloride concentration from 0 to 5.52 wt % reduced the MEG thermal stability time from 44 to 8 h. Thermogravimetric analysis was the most adequate studied technique to quantify MEG thermal degradation. Measurements of MEG degradation were correlated, using an allometric expression for each sodium chloride concentration. The salt-free solutions presented 7.2% MEG degradation after 56 h heating, while for 5.52 wt % NaCl it increased to 21.1%. As expected, sodium chloride concentration and time of exposure to temperatures up to 140 °C are important variables for monitoring MEG thermal degradation, especially in the flash evaporator

From experimental studies in literature, it has been proven that the phase behavior of supercritical carbon dioxide with pure or mixed solvents or solutes may not be simple, and in many cases, a second liquid phase appears. In this work, we considered the phase behavior of supercritical carbon dioxide with two essential oils, namely, eucalyptus oil and rosemary oil. We investigated the phase behavior of each system of CO2 + eucalyptus oil and CO2 + rosemary oil separately, and we observed that both systems form a second liquid phase. We measured the bubble point pressures of both systems for five different concentrations of CO2, and also the three phase line of liquid-liquid-vapor of these systems. Based on the observed upper solution critical points, we concluded that the phase behavior of these two systems is Type-III based on the Scott and Van Konynenburg phase classification.

The aim of this work is to examine the performance of a glass column filled with a sand filter in oil removal from oilfield produced water (OPW) and synthetic produced water (SOPW). This paper investigated the influence of process parameters such as physical characteristics of sand, column height, types of effluent (oilfield produced water and synthetic produced water), and oil concentration on oil removal efficiency. An OPW sample was taken from effluents of the oilfield unity located at Rio Grande do Norte State (Brazil), and the SOPW sample was prepared using two types of oils and salts (NaCl and KCl). The results showed that the oil concentration decreased significantly after the filtration process. The oil removal efficiency was influenced by the sand particle size and bed height, reaching 90% using a 30 cm high sand bed composed by mixed grain sizes.

Ampicillin is one of the most consumed antibiotics. Due to environmental issues the production of ampicillin has been forbidden by the conventional chemical route. An alternative is the enzymatic route followed by crystallization of the antibiotic. Therefore, this work aims the determination of a series of ampicillin and phenylglycine solubility data in aqueous media using an analytical method. The measurements were carried out at 283.15 and 298.15 K, varying the pH between 3 and 8, and ethanol composition up to 70 wt%. Dissociation constants (pKa's) have also been measured at the studied temperatures and ethanol compositions. It is demonstrated that ideal thermodynamic model with the predetermined pKa's is able to describe satisfactorily solubility profiles. Solubility measurements of ampicillin and phenylglycine have been determined at different conditions of industrial interest. These data may be applied for the evaluation of the crystallization step of ampicillin in the enzymatic synthesis.