Mecanismos del proceso de degradación de etanol amina en la captación de CO2 y efecto de los gases de combustión asociados

Se evaluaron los sistemas EA-H2O-Aire y EA-H2O-O2. La pérdida de EA en el sistema EA-H2O-Aire se realizó durante las dos primeras horas, siendo mayor a flujos bajos en comparación con los flujos altos, con un flujo de 11.27 mL/s se perdió en promedio 10.5 %, mientras que con flujo de 35.14 mL/s la pérdida fue de 2.44 %. La pérdida de EA disminuyó a medida que se incrementó el flujo de aire sin depender de los tiempos de suministroCon el objetivo de establecer la contribución del aire y del O2 en ausencia de CO2 en la pérdida de etanol amina (EA) en una solución acuosa al 30 %, para el proceso de captura de CO2 se evaluaron los sistemas EA-H2O-Aire y EA-H2O-O2. Los experimentos se realizaron con suministro de aire y de O2 a temperatura ambiente durante 16 h registrando cada 2 h el pH, la temperatura y la concentración de EA. La pérdida de EA en el sistema EA-H2O-Aire se realizó durante las dos primeras horas, siendo mayor a flujos bajos en comparación con los flujos altos, con un flujo de 11.27 mL/s se perdió en promedio 10.5 %, mientras que con flujo de 35.14 mL/s la pérdida fue de 2.44 %. La pérdida de EA disminuyó a medida que se incrementó el flujo de aire sin depender de los tiempos de suministro. La pérdida de EA en el sistema EA-H2O-O2 no fue significativa cuando el oxígeno se alimentó 16 h en los flujos estudiados.ININ y UAE

Feasibility analysis of a sewage sludge treatment by an irradiation plant in Mexico

Technical and economic analyses of an irradiation plant for sewage sludge treatment determined that an appropriate place for the first sludge electron irradiator in Mexico would be the sewage water treatment plant located north of Toluca in the State of Mexico. This treatment plant is mainly used for domestic wastewater and produces an approximate volume of 70 ton d-1 liquid sewage sludge. Considering a 50 kW power of a 10 Mev electron linear accelerator, an irradiation dose of 5 kGy and a treatment capacity of 346 tons per day, it is estimated that the treatment cost would be of $9.00 US dollars per ton

Comparison of cadmium adsorption by inorganic adsorbents in column systems

Carbonaceous material obtained from industrial sewage sludge and Na-zeolitic tuff were used to adsorb cadmium from aqueous solutions in column systems. The Bohart, Thomas, Yoon–Nelson, and mass transfer models were successfully used to fit the adsorption data at different depths, and the constant rates were evaluated. The parameters such as breakthrough and saturation times, bed volumes, kinetic constants, adsorption capacities, and adsorbent usage rates (AUR) were determined. The results show that the breakthrough time increases proportionally with increasing bed height. The adsorption capacity for cadmium for Na-zeolitic tuff was higher than carbonaceous material. The results indicated that the Na-zeolitic tuff is a good adsorbent for cadmium removal.CONACYT, project 131174Q, and PROMEP/103.5/13/6535 project

Electrocoagulation-Adsorption to remove anionic and cationic dyes from aqueous solution by PV-Energy

The cationic dye malachite green (MG) and the anionic dye Remazol yellow (RY) were removed from aqueous solutions using electrocoagulation-adsorption processes. Batch and continuous electrocoagulation procedures were performed and compared. Carbonaceous materials obtained from industrial sewage sludge and commercial activated carbons were used to adsorb dyes from aqueous solutions in column systems with a 96–98% removal efficiency. The continuous electrocoagulation-adsorption system was more efficient for removing dyes than electrocoagulation alone. The thermodynamic parameters suggested the feasibility of the process and indicated that the adsorption was spontaneous and endothermic (Δ = 0.037 and −0.009 for MG and RY, resp.). The Δ value further indicated that the adsorption process was spontaneous (−6.31 and −10.48; = 303 K). The kinetic electrocoagulation results and fixed-bed adsorption results were adequately described using a first-order model and a Bohart-Adams model, respectively. The adsorption capacities of the batch and column studies differed for each dye, and both adsorbent materials showed a high affinity for the cationic dye.Thus, the results presented in this work indicate that a continuous electrocoagulation-adsorption system can effectively remove this type of pollutant from water. The morphology and elements present in the sludge and adsorbents before and after dye adsorption were characterized using SEM-EDS and FT-IR

Properties of carbonaceous materials from sewage sludge to remove organic matter. Phenol as a particular case

Carbonaceous material obtained from the pyrolysis of sewage sludge, activated carbon (AC), a composite CM(Fe-Cu) (carbonaceous material/nanoparticles of Fe-Cu) and nanoparticles N(Fe-Cu) were used to evaluate and compare their abilities to remove phenol from aqueous solutions by adsorption followed by oxidation. The adsorbents were characterized by scanning electron microscopy, transmittance electron microscopy, Brunauer–Emmett–Teller (BET) surface area, X-ray diffraction and Infrared (IR) spectroscopy. The presence of Fe-Cu nanoparticles was confirmed by the TEM technique. Sorption kinetics and isotherms were determined in the presence and absence of hydrogen peroxide. The experimental kinetic data of the activated carbon and the carbonaceous material were treated with Lagergren, Elovich and Ho models. The results show that both materials are best fit to the second order model indicating a chemisorption mechanism. The adsorption equilibrium of phenol by the different adsorption materials was observed in 24 h. The adsorption capacity of CM(Fe-Cu) for phenol was not affected by the pH, and the adsorption capacities for CM and AC decreased as the pH increased. The isotherms were lineal in all cases. N(Fe-Cu) was the most efficient material for the removal of phenol from aqueous solutions. The adsorption capacities decreased as the doses increased and the adsorption capacities of the materials were not affected by the temperature when it was between 30 and 50°C; only the composite CM(Fe-Cu)in the presence of hydrogen peroxide showed an endothermic behavior. The highest adsorption capacities were for N(Fe-Cu) in the presence and absence of hydrogen peroxide

Removal of indigo carmine by a Ni nanoscale oxides/Schoenoplectus acutus composite in batch and fixed bed column systems

Removal behavior of indigo carmine by Schoenoplectus acutus and Ni nanoscale oxides/Schoenoplectus acutus composite was determined. The characterization of both materials was done by TEM, SEM/EDS, DRX, and BET. Experimental data were best fitted to pseudo second order and Langmuir-Freundlich models for kinetics and isotherm, respectively; these results indicate a chemisorption mechanism on heterogeneous materials. Adsorption capacity of Ni nanoscale oxides/Schoenoplectus acutus composite was high in comparison with other adsorbents (760 mg/g). Adsorption of dye is not affected by pH (3 to 9). Metal nanoparticles supported on cheap and eco-friendly adsorbents are an alternative for the removal of dyes from wastewater

Efficient removal of crystal violet dye from aqueous solutions by vitreous tuff mineral

Textural, structural and morphological characteristics of the vitreous tuff were determined by means of several physicochemical techniques. The nitrogen adsorption isotherm at 77K was fitted with the Brunnauer–Emmet–Teller model and together with the results of the average pore distribution showed a mesoporous material. Samples of vitreous tuff were used as adsorbent to study the removal of crystal violet from aqueous solution. The presence of -OH moieties in the material seems to be responsible for the removal of the dye showing that vitreous tuff can be used as an organic dye adsorbent material. The pseudo-second-order model was the best fit model for describing the sorption process of crystal violet; intraparticle diffusion being the controlling step in the process. The experimental adsorption isotherm was fitted with Langmuir, Freundlich and Langmuir–Freundlich models, showing better correlation with the second one. The adsorption capacity was 170.01 mg/g, being among the highest compared with other inorganic and organic common sorbent materials. The design of single stage of the adsorber can predict the behaviour to potential scale up. This mineral has a very good potential as an adsorbent material for organic dyes.CONACYT scholarship [Grant No. 507915], Universidad Autónoma del Estado de México, project 3211–2012 and PROMEP/103.5/13/6535 project

Starch Modified With Chitosan and Reinforced With Feather Keratin Materials Produced by Extrusion Process: An Alternative to Starch Polymers

They also reached up to 3800% and 3150% in maximum strength, respectively, compared to the matrix. The lysozyme test showed relevant changes in the degradability rate, because the weight loss of the films at 3 weeks decreased from 53% for starch-chitosan matrix and up to 34% for composites with 5wt% of modified quill. The results corroborated that chicken feather materials can be useful for the development of a manufacturing process for starch composites, and the decomposition of starch-chitosan composites can be controlled depending on the content and type of keratin.Starch (potato), chitosan, and feather keratin are used for processing biodegradable films produced by extrusion. The morphology of the films is examined with a scanning electron microscope and showed the excellent dispersion of keratin. The dispersion is the result of compatibility between the polysaccharides and proteins, as well as the proper operation of the extrusion process. Water solubility of the starch-chitosan films decreased with an increase of keratin materials. The storage modulus increased up to 137% for the composites with unmodified ground quill, and by 192% for composites with modified ground quill. In a tensile test, the composites with unmodified and modified quill reached outstanding increments up to 8160 and 7250% in elastic modulus, respectively, compared to the matrixUniversidad Autonoma del Estado de Mexico Tecnologico Nacional de Mexico Universidad Nacional Autonoma de Mexico Universidad Autonoma de Cd. Juare

Estrés oxidativo producido por antiinflamatorios no esteroideos sobre el bioindicador Hyalella azteca

capitulo de libroCon base en los resultados obtenidos en el presente estudio de toxicidad aguda y a la clasificación europea, que considera peligroso ambiental- mente a aquellos fármacos cuya concentración letal media sea menor a 100 mg/L, los AINE; diclofenaco, paracetamol, ibuprofeno, naproxeno y ácido acetilsalicílico, pueden ser considerados dañinos para los ecosiste- mas acuáticos. Los AINE (diclofenaco, paracetamol, ibuprofeno, naproxeno y ácido aceti- lsalicílico) son capaces de producir estrés oxidativo sobre Hyalella azteca, reflejándose en los incrementos de lipoperoxidación y del contenido de proteínas carboniladas, y en los cambios producidos en la actividad de las enzimas antioxidantes SOD, CAT y GPx.conacy

Chitosan–Starch–Keratin composites: Improving thermo-mechanical and degradation properties through chemical modification

The lysozyme test shows an improved in the degradability rate, the weight loss of the films at 21 days is reduced from 73 % for chitosan-starch matrix up to 16 % for the composites with 5wt% of quill; but all films show a biodegradable character depending on keratin type and chemical modification. The outstanding properties related to the addition of treated keratin materials show that these natural composites are a remarkable alternative to potentiat-ing chitosan–starch films with sustainable featuresChitosan–starch polymers are reinforced with different keratin materials obtained from chicken feather. Keratin materials are treated with sodium hydroxide; the modified surfaces are rougher in comparison with untreated surfaces, observed by Scanning Electron Microscopy. The results obtained by Differential Scanning Calorimetry show an increase in the endothermic peak related to water evaporation of the films from 92 °C (matrix) up to 102–114 °C (reinforced composites). Glass transition temperature increases from 126 °C in the polymer matrix up to 170–200 °C for the composites. Additionally, the storage modulus in the composites is enhanced up to 1614 % for the composites with modified ground quill, 2522 % for composites with modified long fiber and 3206 % for the composites with modified short fiber. The lysozyme test shows an improved in the degradability rate, the weight loss of the films at 21 days is reduced from 73 % for chitosan-starch matrix up to 16 % for the composites with 5wt% of quill; but all films show a biodegradable character depending on keratin type and chemical modification. The outstanding properties related to the addition of treated keratin materials show that these natural composites are a remarkable alternative to potentiat-ing chitosan–starch films with sustainable featuresUniversidad Autónoma del Estado de México Tecnológico Nacional de México, Instituto Tecnológico de Querétaro Universidad Nacional Autónoma de México Tecnológico Nacional de México, Instituto Tecnológico de Celaya Universidad Autónoma de Cd. Juáre