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Se evaluó la calidad del agua de seis manantiales que abastecen de agua potable y riego agrícola a la comunidad El Platanal, en Michoacán. Se realizaron dos campañas de colecta, (estiaje y precipitación pluvial). Se evaluaron parámetros fisicoquímicos, microbiológicos y elementos traza. El tipo de agua predominante en la zona fue Ca2+-HCO3-. Se encontraron concentraciones de Fe (0.8 mg/L) superiores a los límites máximos permisibles por las normas mexicanas para agua potable. El sitio (S6) presentó las concentraciones más elevadas de algunos parámetros (NO3-, PO43-, coliformes fecales). El cálculo del Índice de Calidad del Agua (ICA) mostró que el agua en el área de estudio no es apta para uso potable, pero sí para riego agrícola.

The use of guava seeds (GS) and acid-modified guava seeds (MGS) for the removal of Cr(VI) from aqueous solutions was investigated. Batch-type experiments were performed with Cr(VI) aqueous solutions and biosorbents to determine the kinetic and equilibrium sorption parameters. Results indicated that GS and MGS were capable of reducing and remove Cr(VI) from solutions, but the reduction was only observed at some experimental conditions. Infrared analysis showed that several functional groups were involved in the reduction, and biosorption of Cr(VI), particularly alcohol, phenolic, carboxylic, and methoxymethyl structures. The mechanisms of reduction and biosorption depended upon the type of biosorbent, pH, and temperature of the system. The pseudo-second-order kinetic model describes the kinetic sorption data, and the Langmuir-Freundlich (L-F) model describes the isotherm data in most cases. Significantly high total chromium biosorption capacities were obtained. Acid modification of guava seeds improves chromium biosorption performance.

In this paper, the removal of Pb(II) ions from aqueous solutions using cellulose nanofibers (NFC) and crystalline nanocellulose (CNC) was studied. These adsorbents were obtained from water hyacinth (Eichhornia crassipes) by the Kraft process. Characterization was carried out to NFC and CNC by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), showing excellent structural properties and high availability of surface functional groups. The influence of different parameters on the adsorption process was evaluated through batch-type adsorption experiments. The results showed effective lead removal reaching adsorption equilibrium at 180 min. Isotherms results showed maximum adsorption capacities (Qmax) of 80.02, 84.64, and 87.10 mg/g for NFC at 25, 30 and 45 °C, respectively. Results of Pb(II) adsorption isotherms by CNC showed a Qmax of 17.90, 28.20, and 30.36 mg/g at 25, 30 and 45 °C, respectively. Isotherm data were best described by the Langmuir–Freundlich model for NFC, and the Freundlich model best-described CNC isotherm. Lead adsorption mechanisms were different for both biosorbents. The thermodynamic parameters of the process were calculated. Endothermic reactions were observed for both materials. NFC and CNC materials have great potential as biosorbents for the removal of lead ions from water.

Acid mine drainage was evaluated using a galvanic (GV) electrochemical system, Al–Cu (anode/cathode), based on a 32 factorial design. The factors analyzed were anodic area/volume ratios (A/V) of 0.037, 0.072, and 0.112 cm2/cm3, and treatment time from 0.25–8 h, and analyses were performed in duplicate with 11 degrees of freedom. The response variables were the total dissolved solids and concentrations of As, Cu, Co, Cr, Pb, Fe, Ni, and SO42−. The pH, electrical conductivity, and temperature were monitored during the process. Significant differences between treatments were determined by analysis of variance with Tukey’s test (p < 0.05) using Statgraphics Centurion XVI.I software. The results showed that a greater electrode surface, A/V ratio, and treatment time improved pollutant removal. The spontaneous reactions generated by the galvanic cell, through the current that flows owing to the potential difference between the Al and Cu electrodes, allows the removal of heavy metals, arsenic, and SO42− by coagulation and precipitation mechanisms. The removal efficiencies achieved were Cu (99.1%), As (76.6%), Ni (80.2%), Pb (83.6%), Cr (100%), Fe (93.71%), and 92.9% for sulfates. The X-ray diffraction and Raman analyses of the solid fraction indicated that cuprite was formed with a purity of 96%, and the recovery of Cu by the GV system may be a viable option for mining companies.

This work informs on the green synthesis of a novel adsorbent and its adsorption capacity. The adsorbent was synthesized by the combination of iron nanoparticles and cellulose nanofibers (FeNPs/NFCs). Cellulose nanofibers (NFCs) were obtained from Moringa (Moringa oleifera Lam.) by a pulping Kraft process, acid hydrolysis, and ultrasonic methods. The adsorption method has advantages such as high heavy metal removal in water treatment. Therefore, cadmium (Cd) and lead (Pb) adsorption with FeNP/NFC from aqueous solutions in batch systems was investigated. The kinetic, isotherm, and thermodynamic parameters, as well as the adsorption capacities of FeNP/NFC in each system at different temperatures, were evaluated. The adsorption kinetic data were fitted to mathematical models, so the pseudo-second-order kinetic model described both Cd and Pb. The kinetic rate constant (K2), was higher for Cd than for Pb, indicating that the metal adsorption was very fast. The adsorption isotherm data were best described by the Langmuir&ndash, Freundlich model for Pb multilayer adsorption. The Langmuir model described Cd monolayer sorption. However, experimental maximum adsorption capacities (qe exp) for Cd (&gt, 12 mg/g) were lower than those for Pb (&gt, 80 mg/g). In conclusion, iron nanoparticles on the FeNP/NFC composite improved Cd and Pb selectivity during adsorption processes, indicating the process&rsquo, spontaneous and exothermic nature.

This work assessed the groundwater hydrogeochemistry and the drinking water quality of 10 wells supplying the urban area of Zamora, Michoac&aacute, n, Mexico. Two sampling campaigns were conducted in May 2018 (dry season) and November 2018 (wet season) to describe the chemistry of the water and its interaction with the rock. Physical and chemical constituents (temperature, pH, electrical conductivity, color, turbidity, solids, total hardness, total alkalinity, chemical and biochemical oxygen demands), major components (Ca2+, Mg2+, Na+, K+, SO42&minus, PO43&minus, HCO3&minus, CO32&minus, Cl&minus, N-NO3&minus, and N-NH3), as well as trace elements (As, Fe, Mn, Ba, Al, Sb, Co, V, Cu, Cd, Cr, Ni, Zn, Tl, Pb) were analyzed. Results showed groundwater with a slight tendency to alkalinity. The hydrogeochemical facies observed are Ca2+-HCO3&minus, in all sites. Hydrochemical diagrams indicate immature, cold, non-saline, and uncontaminated water with short residence time. Water&ndash, rock interaction predominates. The water in the study area is appropriate for drinking use according to Mexican and international regulations with an excellent quality in 7 wells and good in the other 3.

The removal of fluoride from aqueous solutions by pine sawdust chemically modified with aluminum in batch systems was investigated. The loading process of aluminum in this biomaterial was achieved by the hydrolysis of metal salts. The kinetics andsorption capacities of the unmodified and modified pine sawdust were evaluated. The effect of different parameters such initial fluoride concentration, pH and contact time was studied on the sorption process. Since the presence of other ions may affect the sorption of fluoride, some studies of binary or multiple systems have simulated a real natural water effluent. The aim of this study was the evaluation of competitive ions in the sorptionof fluoride using pine sawdust in fluoride (F−) single systems and F−/HCO3− and F−/SO42− binary systems. Batch-type contact experiments were performed to evaluate the kinetics and equilibrium fluoride sorption, all at 25 °C, 100 rpm and pH values adjusted to 6, 7 and 8 depending on the conditions of the binary or single systems. It was found that the Lagergren model described the F− sorption kinetic data and the Langmuir and Freundlich equations described the equilibria of the sorption binary systems. These results suggested that the sorption mechanism was chemisorption on a heterogeneous material. The pH effects governing sorption capacities were also evaluated, showing a decrease as pH value rises, indicating that this sorption process is highly pH-dependent. The physical characterization of the biosorbent after fluoride removal by infrared analyses showed fluoride removal in different functional groups on the surface of the modified and unmodified biosorbents. The point of zero charge and co-existing ions affected the efficiency of defluoridation significantly. The pine sawdust showed a high affinity for fluoride ions compared with conventional adsorbents; therefore, it can be considered as a good low cost biosorbent for the defluoridation of water.

The contamination of groundwater by arsenic and fluoride is a major problem worldwide, causing diseases in the population that uses these waters for their consumption. Therefore, the removal of these types of pollutants from groundwater is a very important issue. In this work, the removal of arsenate and fluoride from aqueous solutions by using aluminum-modified guava seeds (Al-GSs) was evaluated. Batch-type adsorption experiments were carried out with aqueous solutions of As(V) and F− and Al-GSs. The kinetic and equilibrium parameters of adsorption were determined, as well as the effects of adsorbent dose and pH. The adsorbent was characterized by scanning electron microscopy and infrared spectroscopy in order to determine its morphology and the functional groups present in the material. The results showed that hydroxyl and carboxyl are the main groups involved in the adsorption of As(V) and F−. The fluoride adsorption kinetics indicate that the equilibrium time was reached at 150 min and it can be described by the Lagergren model, while for As(V) the equilibrium time was lower (120 min) and the kinetic data were fitted well to the pseudo-second-order model. The Langmuir-Freundlich model can describe the adsorption equilibrium data in all cases. The fluoride adsorption capacity by Al-GS was 0.3445 mg/g, and for As(V) it was 4 mg/g. It can be established that the removal of arsenates and fluoride in Al-GSs is due to chemisorption on a heterogeneous surface.

Lerma River is one of the largest rivers in Mexico. Over the past 20 years, unplanned population growth occurred along its course and the river has been used as the only outlet for industrial and domestic wastewater disposal. The aim of the present study was to determine trace metals such as Cr, Ni, Cu, Zn, Fe, Pb, and arsenic concentrations at the upper layer of sediments of the Lerma River meander in La Piedad, Michoacan, Mexico. Sediment samples were collected from eight different sites during the rainy and dry seasons. All samples were physically characterized, and concentration values of trace metals and As were determined. On the basis of protection criteria for freshwater sediments, concentrations of Fe, Zn, Cu, Ni, and Pb were found to exceed the lowest effect level; moreover, the concentrations were found to exceed the severe effect level at some sites, particularly for Cu. Statistical analyses showed significant differences between sampling seasons for Fe and As, and among sites for Ni, Cu, Zn, and Pb. In addition, the enrichment factor indicates the following order Zn > Cr > Cu > Ni > Pb > As, and the geoaccumulation index (I geo) indicates contamination in the following order Zn > Cr > Cu > Ni > As > Pb. The Lerma River meander in La Piedad shows a reduction in pollution by trace metals and arsenic near the drain area and downstream of the meander. However, there are significantly higher concentrations of these elements in sediments of sites located in the middle part of the city.

The biosorption of As(V) from aqueous solutions by pine sawdust chemically modified with iron in batch systems was investigated. The loading process of Fe in this biomaterial was achieved by hydrolysis of two different ferric salts. This modification of sawdust is an attempt to improve As(V) biosorption for practical applications. The kinetics and maximum biosorption capacities of the unmodified and modified pine sawdust were evaluated. It was found that the pseudo-second order model described the As(V) biosorption kinetic data and the Langmuir-Freundlich equation described the arsenate sorption equilibrium. These results indicated that the sorption mechanism was chemisorption on a heterogeneous material. The pH effects governing biosorption capacities were also evaluated, showing a decrease as pH value rises, indicating that this biosorption process is highly pH-dependent. The estimated maximum biosorption capacities of As(V), based on the Langmuir-Freundlich fit to the data were, at pH 4, 4.4 mg/g of untreated sawdust, (UN-SW), 12.85 mg/g of ferric chloride modified sawdust (FeCl-SW), and 6 mg/g of ferric nitrate modified sawdust (FeNit-SW); and at pH 7, 2.6 mg/g of UN-SW, 5.9 mg/g of FeCl-SW, and 4.6 mg/g of FeNit-SW. Sorption capacities of iron-modified pine sawdust were evidently higher than other similar biosorbents previously reported.

The sorption of cesium by two different clinoptilolite-rich tuffs from Mexico considering both batch and continuous flow systems was investigated. The kinetic and thermodynamic parameters as well as the sorption capacities of the zeolitic materials at different temperatures were evaluated. It was found that the second order model describes the cesium sorption kinetics and the Langmuir–Freundlich model describe the isotherms, in all cases. According with the thermodynamic parameters the cesium sorption mechanism is ion exchange and endothermic in nature. The mineral and chemical composition of the clinoptilolite-rich tuff influences on the cesium sorption properties.

Summary Corn tortillas are produced using the traditional nixtamalisation process (TP). Nevertheless, one of the greatest problems that the tortilla industry faces is the high level of losses of solids. The aim of this research was to evaluate the nutritional value of a whole-grain tortilla, produced using an ecological process (EP). In the EP corn was cooked at 90 °C with 1.8% (w/w) calcium sulphate. The grains were steeped, washed and grounded to obtain the masa, which was baked to produce tortillas. Also, tortillas were prepared using the TP and following the same steps as those used in the EP, except that 1.0% (w/w) of calcium hydroxide was used. The tortillas from EP retained 14.05, 6.03, and 54.02% more fat, protein and fibre than tortillas produced by the TP. The PER value of rats fed whole-grain tortillas (1.81) was not different from that of rats fed the traditional tortillas (1.85).

The dynamic removal of cadmium from aqueous solutions by natural and surfactant-modified Mexican zeolitic rocks (clinoptilolite–heulandite type) in fixed bed column systems was investigated. The performances of fixed bed columns were described through the breakthrough curves obtained from column experiments and the values of column parameters predicted as a function of bed height. The column adsorption data were evaluated in terms of the bed adsorption capacity and the efficiency of the process. The experimental results fitted well the bed depth service time model (BDST) for both adsorbents, and the empty bed residence time model (EBRT) was used to optimize column operating conditions. The surface modification of the zeolitic rock with surfactant affected the removal of cadmium in fixed bed systems. Moreover, a column experiment with surfactant modified zeolitic rock previously saturated with 4-chlorophenol was carried out and the results showed that this saturation had a negative effect on the performance of the column.

Bacterial influenced corrosion of AISI 316 stainless steels (SS) and ASTM A36 carbon steel by two strains of sulfate reducing bacteria (SRB) were analyzed. Thermophilic and mesophilic bacteria were isolated from the condensate fluid of "Los Azufres", a geothermal electric field located in the State of Michoacan at Central Mexico. Anaerobic corrosion tests were carried out for 15, 30 and 60 days in lactate-containing media at 50 °C and 40 °C. Scanning electron microscopy (SEM) was used to determine corrosion morphology. Pitting density was determined with an optical microscope. Corrosion potential, anodic potentiodynamic polarization curves and pH values were measured under anaerobic conditions. Results show that the microbial activity influenced the overall corrosion process, whereas, pitting corrosion and localized attack corrosion (LAC) were found. The anodic polarization curves show that passivation and activation processes should take place on the steel surface of the sample and pH decreases as the exposure time increases.

The present study involves an investigation on the comparison of a Mexican clinoptilolite‐heulandite zeolitic mineral and the modified zeolitic material with the surfactant hexadecyltrimethylammonium bromide (HDTMA) for the removal of cadmium from aqueous solutions. The effects of pH and contact time on the adsorption process were examined. The optimum pH for adsorption was found to be 7. Cadmium retention reached equilibrium in 32 h and the rate of cadmium adsorption by the zeolites was rapid in the first 10 h. Elovich's model best described the reaction rate. Batch adsorption experiments conducted at room temperature showed that the adsorption pattern followed the Langmuir–Freundlich isotherm model. The cadmium retention capacity decreased very slightly when the zeolite surface was modified with the surfactant HDTMA, and this material has advantages for its use in the removal of some other contaminants, such as anions and nonpolar organic compounds, like phenols. The results showed that natural...

The sorption of cadmium (Cd) and lead (Pb) by calcium alginate beads (CAB) from aqueous solutions in batch systems was investigated. The kinetic and thermodynamic parameters, as well as the sorption capacities of CAB in each system at different temperatures, were evaluated. The rate of sorption for both metals was rapid in the first 10 minutes and reached a maximum in 50 minutes. Sorption kinetic data were fitted to Lagergren, pseudo-second-order and Elovich models and it was found that the second-order kinetic model describes these data for the two metals; comparing kinetic parameters for Cd and Pb sorption a higher kinetic rate (K2) for Pb was observed, indicating that the interaction between lead cations and alginate beads was faster than for cadmium. Similarly, isotherm data were fitted to different models reported in literature and it was found that the Langmuir-Freundlich (L-F) and Dubinin-Radushkevich (D-R) models describe the isotherms in all cases. CAB sorption capacity for cadmium was 27.4 mg/g and 150.4 mg/g for lead, at 25°C. Sorption capacities of Cd and Pb increase as temperature rises. According to the thermodynamic parameters, the cadmium and lead adsorption process was spontaneous and endothermic. It was also found that pH has an important effect on the adsorption of these metals by CAB, as more were removed at pH values between 6 and 7.

The use of biosorbents to remove metals and metalloids from contaminated water systems has gained great usage in various parts of the world. The objective of the current study was to test lemon peels as biosorbents for As (V). Lemon peels were chemically characterized and arsenic contact experiments were performed to determine the adsorption capacity of the peels using different empirical models. The model that fit the experimental data was the Lagergren empirical model with a correlation coefficient of R= 0.8841. The results show that lemon peels were able to retain 474.8 μg of As (V)/g of biosorbent. Practical Application: Lemon agro-industrial waste can be useful in the removal of heavy metals, such as arsenic, from aqueous media.

Cuitzeo Lake is one of the largest and most important lakes in Mexico. It receives different types of pollutants through its main tributary, the Grande River of Morelia. The aim of this work was to determine if high concentrations of iron, zinc, and arsenic are present in sediments in an area near the river mouth to the lake, as well as to estimate the partitioning of these metals using a sequential extraction procedure in order to obtain information of their potential bioavailability. Sediment samples were collected from three different sites in Cuitzeo Lake and two sites in Grande River in both dry and wet seasons. A sequential extraction procedure was carried out to determine the concentrations of these elements in different geochemical phases of the sediments. Total metal concentrations were evaluated by using the enrichment factor and the geoaccumulation index. A comparison with sediment quality guidelines and shale values has also been made. The results indicate that sediments are considered unpolluted by iron and moderately polluted by zinc and arsenic. However, fractionation studies showed that significant amounts of Zn and As could be released to the lake ecosystem depending on the environmental conditions, representing a medium risk potential of bioavailability to the biota.

Facultad de Ingeniería Química. Doctorado en Ciencias en Ingeniería Química Heavy metals and metalloids were among the main pollutants that affected various water bodies around the world, producing effects on human’s health and the environment. Adsorption has been one of the most important methods by removing metal ions in an aqueous solution, so the use of natural resources like cellulose, which has been important in the development of new adsorbents for water treatment. However, those materials were not effective for the removal by specified pollutants due to their hydrophobic nature, so new materials have improved with chemical treatments (non-toxic) and low costs to obtain selectivity. In the present work, the synthesis of a new hybrid adsorbent and its adsorption capacity were studied. The adsorbent was synthesized by combining iron nanoparticles and cellulose nanofibers (NCRI-M-7) by coprecipitación and green chemistry methods. Cellulose nanofibers (NCRI) were obtained from Moringa (Moringa oleifera Lam.) Employing a kraft pulping process, acid hydrolysis, and ultrasonic methods. Therefore, the adsorption of As (V), Cd (II), and Pb (II) with NCRI-M-7 from aqueous solutions in batch systems were investigated. The adsorption experimental results were adjusted to some of the proposed mathematical models and are used to describe the adsorption kinetics and equilibrium, all to identify the dominant mechanisms and obtain their thermodynamic parameters. The results showed effective removal (As, Cd, and Pb) in the kinetics reaching the adsorption equilibrium at 420 minutes. Los metales pesados y los metaloides forman parte de los principales contaminantes que afectan diversos cuerpos de agua alrededor del mundo, produciendo fuertes efectos nocivos a la salud y al ambiente. La adsorción es uno de los métodos más importantes para remoción de diversos iones en solución acuosa, en este contexto el aprovechamiento de recursos naturales con alto contenido de celulosa es de gran importancia en el desarrollo de nuevos adsorbentes para el tratamiento de agua. Sin embargo, en la mayoría de los casos estos materiales no son eficaces para la remoción de algunos contaminantes por su naturaleza hidrofóbica, por lo que se tiene que mejorar con retratamientos químicos (no tóxicos y rentables) para obtener una mejor selectividad. En el presente trabajo se estudió la síntesis de un nuevo adsorbente híbrido y su capacidad de adsorción. El adsorbente se sintetizó mediante la combinación de nanopartículas de hierro y nanofibras de celulosa (NCRI-M-7) por el método coprecipitación y química verde. Las nanofibras de celulosa (NCRI) se obtuvieron a partir de Moringa (Moringa oleifera Lam.) mediante un proceso de pulpeo Kraft, hidrólisis ácida y métodos ultrasónicos. Por lo tanto, se investigó la adsorción de As (V), Cd (II) y Pb (II) con NCRI-M-7 a partir de soluciones acuosas en sistemas discontinuos. Se ajustaron los resultados experimentales de adsorción a algunos de los modelos matemáticospropuestos y se utilizan para describir la cinética y el equilibrio de adsorción, todo ello con el propósito de identificar los mecanismos dominantes y obtener sus parámetros termodinámicos. Los resultados mostraron una efectiva remoción de As, Cd y Pb en las cinéticas llegando al equilibrio de adsorción a los 420 minutos.

Instituto de Investigaciones Agropecuarias y Forestales. Facultad de Biología. Facultad de Medicina Veterinaria y Zootecnia. Facultad de Agrobiología. Facultad de Químico Farmacobiología. Programa Institucional de Maestría en Ciencias Biológicas Pollution is one of the environmental problems that we face today, in particular water pollution due to discharges of textile industries is one of the most serious, which has increased in recent years because these industries have opted to use synthetic dyes to dye their products, which are difficult to degrade, conventional treatments have not been effective in eliminating this type of pollutants. For this reason, techniques are emerging based on the use of microorganisms as well as biosorbent or waste from other industries to remove these contaminants, which, in addition, due to the abundance of these in the environment, low cost and easy application have been efficient in the removal of pollutants Different microorganisms have been used for the removal of contaminants, as in the case of the fungus Phanerochaete chrysosporium, which has been efficient in the removal of dyes. La contaminación es uno de los problemas ambientales al que nos enfrentamos en la actualidad, en particular la contaminación del agua debido a las descargas de industrias textiles es uno de los más graves, el cual ha aumentado en los últimos años debido a que estas industrias han optado por utilizar colorantes sintéticos para teñir sus productos, los cuales son difíciles de degradar; los tratamientos convencionales no han resultado ser eficaces en la eliminación de este tipo de contaminantes. Por tal razón es que surgen técnicas basadas en la utilización de microrganismos, así como biosorbentes o residuos de otras industrias para remover estos contaminantes que, debido a la abundancia de éstos en el ambiente, son de bajo costo, fácil aplicación y han resultado eficientes en remoción de contaminantes. Se han utilizado diferentes microrganismos para la remoción de contaminantes, tal es el caso del hongo Phanerochaete chrysosporium que ha mostrado ser eficiente en la remoción de colorantes. En este trabajo se estudió la remoción del colorante azul directo 71 (AD71) por el proceso de biosorción mediante cáscara de tamarindo y degradación por Phanerochaete chrysosporium.

Facultad de Biología. Facultad de Ingeniería Civil. Facultad de Ingeniería Química. Maestría en Ciencias en Ingeniería Ambiental In this study, was carried out assessing activated carbon (CAP) and activated carbon modified with CaCl2 (CAMP) using as base material Hass avocado peel order to correlate their physicochemical and morphological characteristics with capacity of fluoride adsorption in aqueous solutions. To obtain CAP, a thermal method with a nitrogen atmosphere (N2) was used; CAMP modification was carried out by wet impregnation with CaCl2. Both materials were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy X-ray (EDS), infrared spectrometry, Fourier transform (FT-IR), X-ray diffraction (XRD), surface area by the method of Branauer Emmett and Teller (BET) and isoelectric point (IEP). Subsequently, the chemical characteristics were evaluated according to the ASTM standards and the concentration of active sites by the Boehm method. To determine the kinetics and equilibrium parameters of the system, fluoride adsorption tests were carried out in a batch system. The micrographs of the treated peel revealed a smooth and low porous surface compared to those after calcination where CAP presents an amorphous and porous surface, after the modification spherical particles of Ca were observed on the surface of CAMP. The determination of the surface groups indicates an increase in the concentration for CAMP with respect to CAP, which is verified with the FTIR spectra. Adsorption experiments showed that CAP does not have an affinity for F-, however, there is an increase in fluoride adsorption after the modification of the material with CaCl2. En el presente trabajo de investigación, se llevó a cabo la evaluación de carbón activado (CAP) y carbón activado modificado con CaCl2 (CAMP) utilizando como materia base la cáscara de aguacate Hass con el objetivo de correlacionar sus características fisicoquímicas y morfológicas con su capacidad de adsorción de fluoruro en soluciones acuosas. Para la obtención de CAP se utilizó un método térmico con atmósfera de nitrógeno (N2), la modificación de CAMP se realizó por impregnación húmeda con CaCl2. Ambos materiales se caracterizaron mediante microscopía electrónica de barrido (MEB), espectroscopia de energía dispersiva de rayos X (EDS), espectrometría de infrarrojo por transformada de Fourier (FT-IR), difracción de rayos X (DRX), área superficial por el método de Branauer Emmett y Teller (BET) y punto isoeléctrico (IEP). Posteriormente, se evaluaron las características químicas de acuerdo con las normas ASTM y la concentración de sitios activos por el método de Boehm. Para la determinación de los parámetros de cinética y equilibrio del sistema se efectuaron pruebas de adsorción de fluoruro en un sistema por lotes. Las micrografías de la cáscara tratada revelaron una superficie lisa y poco porosa comparadas con las posteriores a la calcinación donde CAP presenta una superficie amorfa y porosa, posterior a la modificación se observan partículas esféricas de Ca en la superficie de CAMP. La determinación de los grupos superficiales indica un aumento en la concentración para CAMP con respecto a CAP, lo cual se comprueba con los espectros FTIR. Los experimentos de adsorción arrojaron como resultado que CAP no presenta una afinidad por el F-, sin embargo, existe un incremento en la adsorción de fluoruro posterior a la modificación del material con el CaCl2.

Instituto de Investigaciones en Ciencias de la Tierra. Maestría en Geociencias y Planificación del Territorio Life as it is known, is developed mostly in aqueous solutions. The water is so familiar that it has come to be considered as an insipid liquid of simple character, however, it is a chemically reactive substance with extraordinary physical properties. Structures and biological processes can only be understood based on the physical and chemical properties of water (Arreola M. 2015). In the present work a study on the water chemistry of springs and wells adjacent to the geothermal field of Los Humeros, Puebla, is carried out. So far, there are no published reports on the content of major components and trace elements in such springs and wells, so the objective of this work was to carry out a study on the chemical composition of the water in the springs and peripheral wells to the geothermal deposit of Los Humeros, Puebla, thus laying the bases to contribute the first data on the chemistry of the water in this zone. To carry out this work, 23 sites were selected in the geothermal field adjacent area. These temperatures ranging from 9.5 to 34.1°C have been observed, pH values mostly with a tendency to the neutrality in a range between 6.31 and 7.7, dissolved oxygen concentrations up to 9.34 mg / L, electric conductivity values between 63.8 and 1.871 μS /cm and, total alkalinity values between 0.85 and 14.79 meq / L. La vida como se conoce, se desarrolla en su mayoría en disoluciones acuosas. El agua es tan familiar que se ha llegado a considerar como un líquido insípido de carácter simple, sin embargo, es una sustancia reactiva desde el punto de vista químico con propiedades físicas extraordinarias. Las estructuras y los procesos biológicos sólo pueden comprenderse con base en las propiedades físicas y químicas del agua (Arreola, 2015). En el presente trabajo se realizó un estudio sobre la química del agua de manantiales y pozos adyacentes al campo geotérmico de Los Humeros, Puebla. Hasta la fecha no se cuenta con reportes publicados sobre el contenido de componentes mayores y elementos traza en dichos manantiales y pozos, por lo que el objetivo de este trabajo es realizar un estudio sobre la composición química del agua en los manantiales y pozos periféricos al yacimiento geotérmico de Los Humeros, Puebla, sentando de esta manera las bases para aportar los primeros datos sobre la química del agua en esta zona de estudio. Para realizar el trabajo se seleccionaron 23 sitios en la zona adyacente al campo geotérmico, en los que se han observado temperaturas que oscilan entre 9.5 y 34.1 °C, valores de pH en su mayoría con tendencia a la neutralidad en un rango entre 6.31 y 7.7, concentraciones de oxígeno disuelto hasta 9.34 mg/L, valores de conductividad eléctrica entre 63.8 y 1,871 μS/cm y valores de alcalinidad total entre 0.85 y 14.79 meq/L.

Facultad de Biología. Facultad de Ingeniería Civil. Facultad de Ingeniería Química. Maestría en Ciencias en Ingeniería Ambiental The pollution of the water bodies has increased in the last times, principally for the presence of metals weighed as the Cr (VI). Due to the high cost and high time of operation of the methods of treatment, there have developed new technologies that carry out his removal being more efficient and economic, at the same time without causing a negative effect in the environment. Such it is the case of the nanofibers that is obtained from the compression of vegetable fibers that consist of cellulose molecules; and it is 100% renewable and biodegradable. In this work I evaluate the level of efficiency of removal of chromium (VI) by means of the cellulose nanofibers use, as well as the effect of the pH and the temperature in the removal processes. The nanofibers were obtained from waste corrugated paper and their analysis was obtained by infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Batch experiments were carried out to determine the kinetics of adsorption and the influence of temperature and pH. The results show that the equilibrium time was carried out at 30 minutes, obtaining a percentage of removal of 59.5% and 46.4% of total chromium and Cr (VI) respectively. The kinetic model who adjusted to the process was that of Elovich indicating a quimisorción. The images of microscopy demonstrated NFC's presence with a diameter of 40nm. While the IR spectra show the presence of characteristic groups of organic compounds. The hydroxyl, carboxylic and carbonyl groups are responsible for the removal of Cr (VI). La contaminación de los cuerpos de agua ha incrementado en los últimos tiempos, principalmente por la presencia de metales pesados como el Cr (VI). Debido al alto costo y elevado tiempo de operación de los métodos de tratamiento, se han desarrollado nuevas tecnologías que lleven a cabo su remoción siendo más eficientes y económicas, al mismo tiempo sin causar un efecto negativo en el ambiente. Tal es el caso de las nanofibras que se obtienen a partir de la compresión de fibras vegetales que constan de moléculas de celulosa; y es 100% renovable y biodegradable. En este trabajo se evalúo el nivel de eficiencia de remoción de cromo (VI) mediante la utilización de nanofibras de celulosa, así como el efecto del pH y la temperatura en los procesos de remoción. Las nanofibras se obtuvieron de deshechos de cartón corrugado y su análisis se obtuvo mediante espectroscopia infrarroja (FT-IR) y microscopía electrónica de barrido (MEB). Se llevaron a cabo experimentos tipo lote para determinar la cinética de adsorción y la influencia de la temperatura y el pH. Los resultados demuestran que el tiempo de equilibrio se llevó a cabo a los 30 minutos, obteniéndose un porcentaje de remoción del 59.5% y 46.4% de cromo total y Cr (VI) respectivamente. El modelo cinético que se ajustó al proceso fue el de Elovich indicando una quimisorción. Las imágenes de microscopía demostraron la presencia de NFC con un diámetro de 40nm. Mientras que los espectros del IR muestran la presencia de grupos característicos de compuestos orgánicos. Siendo los grupos hidroxilo, carboxílico y carbonilo los responsables de la remoción del Cr (VI).

Facultad de Biología. Facultad de Ingeniería Civil. Facultad de Ingeniería Química. Maestría en Ciencias en Ingeniería Ambiental Iron and some of its oxides derivatives are materials used in the treatment of wastewater, due to their capacity to eliminate contaminants, the nanoparticles of these materials show unique physical and chemical properties. Chitosan has adsorption properties of various aquatic contaminants. This biopolymer has reactive amino and hydroxyl groups that, when combined with magnetic particles, magnetic chitosan compounds, present certain characteristics such as: adsorption of several toxic pollutants in aqueous solution, fast rate of adsorption, they are easy to recover and are a recyclable tool for the removal of heavy metal ions. Therefore, it is proposed to use chitosan and iron nanoparticles to obtain a composite; to which and its capacity to adsorb dissolved arsenic in aqueous solutions was determined. For the synthesis of the composite, first the micro-chitosan was obtained, through the use of microwaves and spray dryer, to later modify it with iron nanoparticles. The composition was characterized by electron microscopy, infrared spectroscopy and zeta potential. The arsenic adsorption process was determined by removal tests, such as: adsorption kinetics, optimal adsorbent dose, influence of temperature and pH and adsorption isotherms. El hierro y algunos de sus derivados óxidos son materiales empleados en el tratamiento de aguas residuales debido a su capacidad de eliminación de contaminantes, las nanopartículas de estos materiales muestran propiedades físicas y químicas únicas. El quitosano presenta propiedades de adsorción de diversos contaminantes acuáticos. Este biopolímero presenta grupos amino e hidroxilos reactivos que, al combinarse con partículas magnéticas, compuestos de quitosano magnéticos, presentan ciertas características tales como: adsorción de varios contaminantes tóxicos en disolución acuosa, rápida tasa de adsorción, son fáciles de recuperar y son una herramienta reciclable para la eliminación de iones de metales pesados. Por lo tanto, se propone emplear quitosano y nanopartículas de hierro para obtener un compósito; al cual y se le determinó su capacidad para adsorber arsénico disuelto en disoluciones acuosas. Para la síntesis del compósito, primero se obtuvo el micro-quitosano, por medio del uso de microondas y spray dryer, para después modificarlo con nanopartículas de hierro. La caracterización del compósito se realizó mediante microscopía electrónica, espectroscopia infrarrojo y potencial zeta. El proceso de adsorción de arsénico se determinó mediante pruebas de remoción, tales como: cinética de adsorción, dosis óptima de adsorbente, influencia de temperatura y pH e isotermas de adsorción.

Facultad de Biología. Facultad de Ingeniería Civil. Facultad de Ingeniería Química. Maestría en Ciencias en Ingeniería Ambiental Pb (II) is one of the main pollutants affecting various water bodies around the world, producing strong adverse health and environmental effects. Therefore, it is important and urgent to remove this pollutant from effluents. In this paper the removal of Pb (II) ions from aqueous solution was studied using cellulose nanofibers (NFC) and crystalline nanocellulose (NCC) under batch type experiments. Two effective adsorbents were synthesized from Eichhornia crassipes (water lily), which is considered as a strong pest in the world. A qualitative characterization was carried out to determine the type of major functional groups in NFC and NCC by infrared spectroscopy (FTIR); later, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses were performed to determine the morphology of the adsorbents and X-ray diffraction (XRD) to study the crystalline region present in NCC. The influence of different parameters was evaluated to optimize the adsorption process, such as: adsorbent dose, contact time, initial pH and temperature. Kinetic experiments were conducted to evaluate the time of adsorption equilibrium of Pb (II) with NFC and NCC at 25 ° C and 100 rpm; the results showed an effective removal of lead reaching adsorption equilibrium at 180 min of contact. An optimal dose of 0.04 g was selected, obtaining a high efficiency at pH 6. Isotherms results evaluated at 25 ° C, 30 ° C and 40 ° C showed maximum adsorption capacities (Qmax) of 87.10 mg/g and 30.36 mg/g for NFC and NCC, respectively. El Pb (II) es uno de los principales contaminantes que afecta diversos cuerpos de agua alrededor del mundo, produciendo fuertes efectos nocivos a la salud y al ambiente. Debido a esto es importante y urgente la eliminación de este contaminante de los efluentes. En el presente trabajo se estudió la remoción de iones de Pb (II) en solución acuosa, utilizando nanofibras de celulosa (NFC) y celulosa cristalina (NCC), bajo experimentos tipo lote. Se desarrollaron dos efectivos adsorbentes sintetizados a partir de Eichhornia crassipes (Lirio acuático) considerada como una plaga a nivel mundial. Se realizó una caracterización cualitativa para determinar el tipo de grupos funcionales mayoritarios en NFC y NCC mediante espectroscopía infrarrojo (FTIR); posteriormente se realizaron análisis de microscopía electrónica de barrido (MEB) y microscopia electrónica de transmisión (TEM) para conocer la morfología de los adsorbentes, y difracción de rayos X para estudiar la región cristalina presente en NCC. Se evaluó la influencia de diferentes parámetros para optimizar el proceso de adsorción como: dosis del adsorbente, tiempo de contacto, pH inicial y temperatura. Se realizaron experimentos de cinética para evaluar el tiempo de equilibrio de adsorción de Pb(II) con NFC y NCC a 25°C y 100 rpm; los resultados mostraron una efectiva remoción de plomo en la cinética llegando al equilibrio en 180 minutos. Se seleccionó una dosis óptima de 0.04 g, obteniéndose una mayor eficiencia a pH 6. Los resultados de las isotermas evaluadas a 25°C, 30°C y 40°C mostraron capacidades máximas de adsorción (Qmax) de 87.10 mg/g y 30.36 mg/g para NFC y NCC, respectivamente.

Facultad de Biología. Facultad de Ingeniería Civil. Facultad de Ingeniería Química. Maestría en Ciencias en Ingeniería Ambiental The principle of the fenton reaction is based on mix iron ions with hydrogen peroxide under acidic conditions to generate highly reactive hydroxyl radicals, which it can be capable of oxidizing organic molecules in aqueous media. In recent years there have been modifications to this reaction with the use of catalysts zeolitics. The aim of this work was to study the potential of a natural zeolite type clipnoilolite, later used as catalyst to degrade synthetic lignin as model pollution from pulp and paper industry. For this purpose the ferric chloride was incorporated into the zeolite using the ion exchange technique. The zeolitic material obtained was characterized structurally and morphologically through, X-ray diffraction, infrared spectroscopy and scanning microscopy. An experimental statistical design was used to evaluate the degradation of kraft lignin. All experiments were performed in a lab scale.The effects of independent variables considered for the oxidative process were pH of the solution, catalyst concentration, hydrogen peroxide concentration and lignin concentration. For the heterogeneous fenton it was determined the reaction conditions at pH 3, were concentration of catalyst of 3 g/L and hydrogen peroxide concentration of 30 mM. In these conditions, 240 min of treatment resulted in a 52 % decrease in lignin. El principio de la reacción fenton se basa en mezclar iones de hierro con peróxido de hidrógeno bajo condiciones ácidas para generar radicales hidroxilos altamente reactivos, que pueden ser capaces de oxidar moléculas orgánicas en medio acuosas. En los últimos años se han hecho modificaciones a la reaccion fenton, como el uso de catalizadores zeolíticos. El objetivo de este trabajo fue estudiar el potencial de utilizar una zeolita natural tipo clipnotilolita para utilizarse como catalizador para degradar lignina sintética como modelo de contaminación de la industria de celulosa y papel. Para este propósito se uso el cloruro férrico como precursor para ser incorporado en la zeolita utilizando la técnica de intercambio iónico. El material zeolítico obtenido fue caracterizado estructuralmente y morfológicamente mediante, difracción de rayos X, espectroscopia infrarrojo y microscopia de barrido. Se empleó un diseño factorial estadístico para evaluar las degradaciones de lignina. Todos los experimentos se realizaron en una configuración a escala de laboratorio. Se analizaron los efectos de las variables dependientes como son, el pH de la solución, la concentración de catalizador, concentración de peróxido de hidrógeno y concentración de lignina. Para el fenton heterogéneo se determinó que las mejores condiciones de reacción fueron a pH de 3, concentración de catalizador de 3 g/L y concentración de peróxido de hidrógeno de 30 mM. En estas condiciones y 240 min de tratamiento dio como resultado en una disminución de 52 % en lignina.

Facultad de Biología. Facultad de Ingeniería Civil. Facultad de Ingeniería Química. Maestría en Ciencias en Ingeniería Ambiental The use of agricultural waste such as biosorbent is promising because of its abundance and low cost. (Foo et al., 2011). Psidium guajava better known as Guava is an important fruit, considered native to Mexico and stretches along South America, Europe, Asia, Africa and India. Michoacán ranks first nationally in production of guava, with a harvest of 131 000 093 tonnes. Skin Guava is commonly discarded, like seeds, while the soft flesh of the center is used as feed for the preparation of juices and sausages. This product generates a significant amount of agricultural waste, and recycling and reuse of it can greatly reduce the mass of waste and its impact on the environment. In this work the seed guava was used, which was washed, ground and sieved to obtain a particle 1mm and modified with ferric chloride to be used in experiments batch type sorption and columns packed and solutions of sodium arsenate. There are several mathematical models in the literature are used to describe the kinetics and equilibrium sorption. In this experimental work some of these models in order to identify the dominant mechanisms in both kinetic and equilibrium of the systems studied were adjusted results. He results show that modified seed guava can remove significant amounts of arsenic from water and that the main mechanism of removal was by chemisorption according to the models applied. The efficiency of the columns is acceptable considering the conditions in which they were operated. This work demonstrates that the use of industrial waste guava after preparation can be used to remove arsenic from aqueous solutions according to the results obtained for the systems studied. El uso del desecho agrícola como biosorbente es prometedor debido a su abundancia y su bajo costo. (Foo et al., 2011). Psidium guajava mejor conocida como guayaba, es una fruta importante considerada como nativa de México y se extiende a lo largo de América del Sur, Europa, Asia, África e India.. Michoacán ocupa el primer lugar a nivel nacional en producción de guayaba, con una cosecha de 131 mil 093 toneladas, la piel de la guayaba es comúnmente desechada, al igual que las semillas, mientras que la carne blanda del centro es usada como alimento para la preparación de jugos o de embutidos. Este producto genera un monto significativo de desecho agrícola, y el reciclaje y rehúso de éste puede en gran medida reducir la masa de desecho y su impacto en el ambiente. En este trabajo se utilizó la semilla de guayaba, la cual se lavó, molió y tamizo hasta obtener una partícula de 1mm y se modificó con cloruro férrico para ser utilizada en experimentos de porción tipo lote y en columnas empacadas y soluciones de arsenato de sodio. Existen diferentes modelos matemáticos en la literatura que se utilizan para describir la cinética y el equilibrio de porción. En este trabajo se ajustaron los resultados experimentales a algunos de estos modelos con el propósito de identificar los mecanismos dominantes tanto en la cinética como en el equilibrio de los sistemas estudiados. Los resultados muestran que la semilla de guayaba modificada es capaz de remover cantidades considerables de arsénico del agua y que el mecanismo principal de remoción fue por quimisorción de acuerdo a los modelos aplicados. La eficiencia de las columnas es aceptable considerando las condiciones en que fueron operadas. Este trabajo demuestra que la utilización de los desechos de la industria de la guayaba después de su acondicionamiento pueden ser utilizados para la remoción de arsénico de soluciones acuosas según los resultados obtenidos para los sistemas estudiados.

Facultad de Biología. Facultad de Ingeniería Civil. Facultad de Ingeniería Química. Maestría en Ciencias en Ingeniería Ambiental The textile industry is one of the main sources of water pollution, it use great number of dyes resistant to degradation naturally, when the water resources is contaminated flora and fauna of aquatic systems is disturbed due to of the large amounts of toxic pollutants discharged into water bodies. On the other hand water availability is reduced for any use. The textile industry has had an overexploitation and overconsumption of clothes, increasing alarmingly the emitted pollutants. Therefore, viable wastewater treatment methods for this type of dyes are searched to reduce the environmental risk. This thesis is focuseds on the evaluation of decoloration of azo dye Direct Blue 71 in aqueous solution by the Fenton process. A factorial design 25 was carried out, that is, five factors to two levels each one. The evaluated variables were [H2O2], [FeSO4], [AD71], temperature and pH, the reaction time of treatment was 3 h with stirring in an isothermal controlled bath. Moreover, the toxicity on Artemia franciscana of the dye, [FeSO4] and of the treatment 4 was evaluated. The experiments were carried out at different concentrations in a exposure of 24 h in darkness at a temperature of 28oC. The best results obtained for dye decoloration according to the graphics the factors Minitab main were at 40 °C, 0.8 mL of hydrogen peroxide, 3 mg/L of ferrous sulfate, pH 3 and 100 mg/L of dye, obtaining the higher percentages of decoloration near to 100%. Regarding effluent toxicity, the results showed 0% mortality for the dye and the treatment, while the ferrous sulfate showed a LC(50)=179.40 mg L-1 to 24 h exposure in A. fraciscana. La industria textil es una de las principales fuentes de contaminación del agua, utiliza un sin número de colorantes resistentes a su degradación natural, al contaminarse el recurso agua se perturba primeramente la flora y fauna de los sistemas acuáticos debido a las grandes cantidades de contaminantes tóxicos descargados en los cuerpos de agua, por otro lado, se reduce la disponibilidad del agua para cualquiera de sus usos. La industria textil ha tenido una sobrepoblación y un consumo excesivo de prendas, incrementando de manera alarmante los contaminantes emitidos. Debido a ello se buscan metodologías viables para el tratamiento de aguas residuales principalmente con este tipo de colorantes y de esta manera reducir el riesgo ambiental. Esta tesis se enfocó a evaluar la decoloración del colorante azo Azul Directo 71 en solución acuosa por el proceso Fenton, Se realizó un diseño factorial 25, es decir, 5 factores a 2 niveles. Las variables a evaluar fueron, [H2O2], [FeSO4], [AD71], temperatura y pH, el tiempo de reacción de los tratamientos fue de 3 h mediante agitación constate en un baño de agua isotérmico controlado. Así también se valoró la toxicidad sobre Artemia franciscana del colorante, [FeSO4] y tratamiento 4, se realizaron a diferentes concentraciones en una exposición de 24 h en obscuridad a una temperatura de 28oC. Los mejores resultados obtenidos en la decoloración de acuerdo los gráficos de factores principales del programa MINITAB fueron a 40oC, 0.8 mL de peróxido de hidrogeno, 3 mg/L de sulfato ferroso, pH 3 y 100 mg/L de colorante, obteniendo porcentajes de decoloración cercanos 100%. En cuanto a la toxicidad se obtuvieron resultados de 0% de mortalidad para el colorante y el tratamiento, mientras que el sulfato ferroso presento una LC(50) de 179.40 mg L-1 a un exposición de 24 h de intoxicación en A. franciscana.

Facultad de Biología. Facultad de Ingeniería Civil. Facultad de Ingeniería Química. Maestría en Ciencias en Ingeniería Ambiental Even though dyes are one of the hardest wastes to remove from water, they are very used all over the world. In the textile industry, the concentration of dyes in wastewater is from 100 to 500 mg/L. Within the different methods to remove dyes from water in included the adsorption. Adsorption is considered one of the best techniques because its low cost, is simple in design, it has high decontamination efficiency and the ability to treat water with high levels of pollutants. Nowadays, the use of agricultural wastes in adsorption is having a big peak in pollutants removal. Guava seed, which represent 4% of total guava weight, it’s made, in its majority, from lignin and cellulose. The guava seed has been used in the removal of different pollutants in water solutions such as trartrazine, Blue No. 1, Red No. 6, Cr VI, fluoride, etc. With the purpose of not only changing the pollutant from aqua solution to a solid medium, the basidiomycete Phanerochaete chrysosporium, that has been used for its ability of degrade different lignocellulosic compounds and other organic compounds, as azo dyes. Material characterization, sorption kinetics, seed doses, pH influence and sorption isotherms were made to evaluate the natural guava seed (SN) and modified guava seed (SM) ability of removing Red Remazol Int R-GB (RR). After this, the basidiomycete Phanerochaete chrysosporium was used to degrade the dye RR conteined in the SM. A pesar de que los colorantes son uno de los desechos más difíciles de tratar, son altamente utilizados. En la industria textil, la concentración de colorante en el agua residual va desde 100 hasta 500 mg/L. Dentro de los métodos existentes para tratar el agua con color se encuentra la adsorción, la cual es considerada una de las mejores técnicas debido a su bajo costo, simplicidad de diseño, alta eficiencia de descontaminación y la habilidad de tratar aguas con altos niveles de concentración de colorantes. El uso de desechos agrícolas en la adsorción está teniendo mucho auge en la remoción de contaminantes. La semilla de guayaba, la cual representa el 4% del peso total de la guayaba, está constituida en su mayoría por celulosa y lignina. Anteriormente, ha sido utilizada exitosamente en la remoción de contaminantes en soluciones acuosas tales como tartracina, colorante azul No. 1, rojo No. 6, cromo VI, floruros, entre otros. Con la finalidad de no cambiar el contaminante de un medio líquido a un medio sólido, se trabajó con el hongo Phanerochaete chrysosporium, el cual ha sido utilizado anteriormente por su capacidad de degradar distintos compuestos lignocelulósicos y otros compuestos orgánicos, como los colorantes de tipo azo. En el presente trabajo se evaluó la capacidad de remoción del colorante Rojo Remazol Int R-GB (RR) por parte de la semilla de guayaba natural (SM) y modificada (SM) con ácido sulfúrico (H2SO4), realizando la caracterización del material, cinéticas de adsorción, experimentos de dosis de semilla, influencia de pH e isotermas de adsorción, con la finalidad de encontrar los parámetros para la óptima remoción del colorante. Posterior al trabajo de remoción de soluciones acuosas se trabajó en sólido para degradar el colorante de la semilla con el hongo P. chrysosporium.

Instituto de Investigación en Metalurgia y Materiales. Maestría en Metalurgia y Ciencias de los Materiales Gold and silver are precious metals of great interest in the trade as they have a wide variety of applications, for which their demand has increased considerably in the last decade. Conventional methods of obtaining these metals such as solvent extraction, chemical precipitation and ion exchange result in high operating costs, the use of large volumes of chemicals, waste generation, among others. These disadvantages have resulted in the development of the biomining, discipline that involves the use of microorganisms for the production of metals by various metabolic processes. Being the biosorption one of the most applyed procedures for recoverying both toxic and valuable metals. In this research the fungus Aspergillus niger 16404 was used, as biosorbent of Au and Ag in solution through the production of biomass either pulverized or forming pellets. Biosorption kinetics with a concentration of gold and silver to 1 ppm and 3 ppm were experimentally tested, obtaining recoveries above 95% in the case of pulverized biomass; the process involving dead biomass as pellets was less efficient achieving recoveries below 96%, the two system adjusted to the Elovich kinetics model. The process of biosorption of gold and silver with both biomasses was coupled with the model of Langmuir-Freundlich isotherm, which describes the biosorbent surface as heterogeneous. Maximum recovery values of gold and silver were obtained with fungal spray biomas of 77.72 mg of gold per gram of biomass and 64.14 mg of silver per gram of biomass. El oro y la plata son metales preciosos de gran interés en el comercio ya que poseen una amplia variedad de aplicaciones, por lo cual su demanda ha ido en aumento considerablemente en la última década. Los métodos convencionales de obtención como extracción con disolventes, precipitación química y el intercambio iónico presentan alto costo operacional, el uso de grandes volúmenes de productos químicos, generación de desechos, entre otros. Estas desventajas han resultado en el desarrollo de la biominería, disciplina que implica la utilización de microorganismos para la obtención de metales por diversos procesos metabólicos. Siendo el mecanismo de biosorción uno de los aplicados a procesos de recuperación de metales tanto tóxicos como valiosos. En el presente trabajo se usó del hongo Aspergillus niger 16404, como biosorbente de Au y Ag en solución por medio de la producción de biomasa pulverizada y en forma de pellets. Se realizaron cinéticas de biosorción partiendo de concentraciones de oro y plata a 1 ppm y 3 ppm, obteniendo rendimientos por encima del 95% de recuperación con biomasa pulverizada, el proceso con biomasa muerta en forma de pellets fue menos eficiente para la recuperación con un rendimiento por debajo de 96%, ambos sistemas se ajustaron al modelo de cinética de Elovich. El proceso de biosorción de oro y plata con ambas biomasas se acoplo al modelo de isoterma de Langmuir-Freundlich que describe la superficie del biosorbente como heterogénea. Se obtuvieron valores de máxima recuperación de oro y plata con biomasa fúngica pulverizada de 77.72 mg de oro por cada gramo de biomasa y 64.14 mg de plata por cada gramo de biomasa.

Facultad de Biología. Facultad de Ingeniería Civil. Facultad de Ingeniería Química. Maestría en Ciencias en Ingeniería Ambiental In several aquifers in Mexico have been detected arsenic and fluoride concentrations above the ceiling set by national standards, causing health problems to the people who use and consume water. Aquifers Acámbaro Valley and Lake Cuitzeo are in the middle of the Lerma River subregion having arsenic and fluoride contamination of natural origin due to the geology of volcano-sedimentary and igneous intrusive and extrusive type. The aim of this study was to evaluate the concentration of arsenic and fluoride in drinking water from 4 wells and 2 springs that supply to municipalities and Jerécuaro Acambaro Guanajuato; and for this the physicochemical, bacteriological parameters were determined, as well as heavy metals. Samples were taken in 4 times of the year: December 2011, January, April and August 2012. En varios acuíferos de México se han detectado concentraciones de arsénico y flúor por arriba del límite máximo establecido por los estándares nacionales, ocasionando problemas de la salud a la población que usa y consume el agua. Los acuíferos del Valle de Acámbaro y del Lago de Cuitzeo se encuentran en la subregión media del río Lerma que presenta contaminación de arsénico y flúor de origen natural debida a la geología de tipo volcanosedimentaria, sedimentaria e ígnea intrusiva y extrusiva. El objetivo de este trabajo fue evaluar la concentración de arsénico y flúor en el agua potable de 4 pozos y 2 manantiales que abastecen a los Municipios de Acámbaro y Jerécuaro en Guanajuato; y para ello se determinaron los parámetros fisicoquímicos, bacteriológicos, así como metales pesados. Las muestras se tomaron en 4 periodos del año: diciembre 2011, enero, abril y agosto 2012.

Facultad de Biología. Facultad de Ingeniería Civil. Facultad de Ingeniería Química. Maestría en Ciencias en Ingeniería Ambiental The main objective of this study was to evaluate the removal of Cr (VI) and total chromium quince shell, using a batch system. Were placed 5 g/L of biosorbent in 3 beakers containing 200 mL of a solution of potassium dichromate (K2Cr2O7).The parameters analyzed were temperature at 25, 35 and 40 ° C, initial concentrations of Cr (VI) of 1, 10 and 20 mg / L, and pH values of 2, 7 and 9. The hexavalent chromium analysis was performed by spectrophotometry UV-vis and total chromium technique by atomic absorption spectrophotometry. It was found that within 60 minutes of contact shell was able to decrease the concentration of Cr (VI) up to 80%. Subsequently, total chromium concentrations decreased at 120 minutes of contact reaching maximum biosorption at 6 hours. Throughout the experimental period was detected presence of Cr (III) in the solution, so that the shell quince proved capable of transforming at least part of the Cr (VI) initial to Cr (III). The most influential parameter on the kinetics of reduction was the initial concentration of Cr (VI), obtaining better results in concentrations of 1 and 10 mg / L and the pH was the most influential parameter on the biosorption kinetics, reaching 60% biosorption to pH 2 and at a contact time of 1 hour. The pseudo-second order model described kinetics biosorption of chromium, suggesting that the kinetic mechanism of total chromium removal is the chemi-sorption. The Langmuir model was the best fit to the data of the isotherms, so it is assumed that the sorption occurs at specific locations on the surface of the sorbent and that once the ion occupies a site can not occur then another sorption in this same place. El objetivo principal de este trabajo fue evaluar la remoción de Cr (VI) y cromo total por la cáscara de membrillo, mediante un sistema por lotes. Se colocaron 5 g/L de biosorbente en 3 vasos de precipitado que contenían 200 mL de una solución de dicromato de potasio (K2Cr2O7). Se analizaron los parámetros de temperatura a 25, 35 y 40 °C, así como concentraciones iniciales de Cr (VI) de 1, 10 y 20 mg/L, y valores de pH de 2, 7 y 9. El análisis de cromo hexavalente se realizó por la técnica de espectrofotometría UV-vis y de cromo total por la técnica de espectrofotometría de absorción atómica. Se encontró que en los primeros 60 minutos de contacto la cáscara fue capaz de disminuir la concentración de Cr (VI) hasta en un 80%. Subsecuentemente, las concentraciones de cromo total disminuyeron a partir de los 120 minutos de contacto alcanzando su máxima capacidad de biosorción a las 6 horas. Durante todo el periodo experimental se detectó la presencia de Cr (III) en la solución, por lo que la cáscara de membrillo demostró ser capaz de transformar al menos parte del Cr (VI) inicial a Cr (III). El parámetro más influyente en la cinética de reducción fue la concentración inicial de Cr (VI), obteniendo mejores resultados a concentraciones de 1 y 10 mg/L; y el pH fue el parámetro más influyente en la cinética de biosorción, alcanzando hasta 60% de biosorción a pH 2 y en un tiempo de contacto de 1 hora. El modelo de pseudo-segundo orden describió la cinética de biosorción de cromo, lo que sugiere que el mecanismo cinético de remoción de cromo total es la quimi-sorción.

Instituto de Investigaciones Agropecuarias y Forestales. Facultad de Biología. Facultad de Medicina Veterinaria y Zootecnia. Facultad de Agrobiología. Facultad de Químico Farmacobiología. Programa Institucional de Maestría en Ciencias Biológicas Formaldehyde and copper sulphate are commonly used in the industry as surface cleaning agents and as algaecides in water treatment plants, this means they are usually thrown into water bodies. Their potential and environment impact have been studied thoroughly. The combined effects that these toxic products have provoke a greater negative impact than those caused individually. Polluting agents, such as metals, are highly dependent on abiotic factors (temperature, pH and salinity), which modify the chemical species that are present. The cupric ion (Cu2+) found in water bodies at 7.4 pH is the most available toxic species. It is able to be added to food chains and unleashing bioconcentration, bioaccumulation and biomagnifications processes. The objective of this study was to evaluate the water’s acute toxicity (LC50) of copper sulphate, formaldehyde and their binary mix (1:1 proportion) in “Artemia franciscana” “nauplii I” of 24 hours of age. The “nauplii I” were exposed to a synthetic sea water solution at formaldehyde concentrations of 0.3, 0.6, 0.9, 1.2, 1.5, 1.8, 2.1 and 2.4 mg/L for a period of 24 hours. The resulting LC50‘s for copper sulphate and formaldehyde were 1.4 mg/L and 1.38 μL/L respectively. Compared to the acute toxicity classification proposed by the Organization for Economic Cooperation and Development (OECD) and the US Environmental Protection Agency (EPA), the copper sulphate’s LC50 corresponds to a moderately toxic substance while the formaldehyde’s corresponds to a highly toxic one. The acute toxicity results of the mix show LC50-24h values of 1.16 mg/L for copper sulphate and 0.71 μL/L for formaldehyde. The mixture’s type of interaction is synergistic according to the Synergic “Proportion (SP)” and “Concentration Addition (CA)” models. El formaldehido y sulfato de cobre son comúnmente utilizados en la industria, para limpieza de superficies como alguicidas en plantas de tratamiento de aguas y finalmente son vertidos a los cuerpos de agua. Los efectos combinados que estos productos tóxicos pueden tener, provocan un impacto negativo mayor que como componentes individuales. Los metales son altamente dependientes de los factores abióticos los cuales modifican las especies químicas presentes, el ion cúprico (Cu+2) en cuerpos de agua a pH 7.4 es la especie tóxica disponible e incorporada a las cadenas alimentarias. En el presente trabajo se evaluó la (LC50) del sulfato de cobre, formaldehido y su mezcla binaria (proporción 1:1) en nauplios I de Artemia franciscana de 24 h de edad; estos se expusieron en solución de agua marina sintética a concentraciones de 0.3, 0.9, 1.2, 1.5, 1.8, 2.1, 2.4 mg/L sulfato de cobre y de 0.54, 0.71, 0.89, 1.11, 1.32, 1.5, 1.8, 2.02, 2.17, 2.84, 3.59, 4.44, 5.37, 6.39, 7.48 μL/L. de formaldehido. LC50s resultantes para sulfato de cobre y formaldehido fueron 1.4 mg/L y 1.38μL/L respectivamente. Los resultados de toxicidad aguda (LC50-24h) de la mezcla, de 1.16 mg/L para el cobre y 0.71μL/L para el formaldehido. Según la clasificación de toxicidad aguda propuesta por la Organización para la Cooperación y el Desarrollo Económicos (OCDE), la LC50 de cobre corresponde a una sustancia moderadamente tóxica, y el formaldehido altamente toxica. El tipo de interacción en la mezcla es sinérgico de acuerdo a los modelos Proporción Sinérgica (PS) y Concentración Adición (CA).

Instituto de Investigaciones Agropecuarias y Forestales. Facultad de Biología. Facultad de Medicina Veterinaria y Zootecnia. Facultad de Agrobiología. Facultad de Químico Farmacobiología. Programa Institucional de Maestría en Ciencias Biológicas The high levels of arsenic from natural origins, found in some drinking water wells in the municipalities of Araró and Cuitzeo, at Michoacan, is a problem that is causing concern because of the risk to the human health of the communities in the area. Therefore, it is necessary to develop remediation methods to reduce the amount of arsenic in water that is extracted from the aquifers contaminated with the element. Consequently, it is important to focus the research on the exploration of alternatives to remove arsenic using available low cost materials; examples of these materials are the agro-industrial waste and the different fungal biomasses. The objective of this investigation was to evaluate the adsorption capacity of arsenic in aqueous solutions of three different types of biomass: lemon waste, dead biomass of fungus Trichoderma atroviride and a mixed biomass composed by the fungus grown on the lemon wastes. These biomasses were conditioned and characterized by chemical analysis to determine their major components; later, FT-IR and SEM analyses were performed to determine the morphology of each biomass. Batch-type arsenic adsorption experiments were accomplished and the supernatants were analyzed by AA-IG. The results were adjusted to the respective empirical models. The results show in all biomasses a chemical sorption process. The biomass with the highest sorption capacity was lemon waste and it was approximately two times higher than other biomasses tested. It can be concluded from this results that, for this type of mixed biomass, removal is not as efficient as it is when biomasses were used separately. Los altos niveles de arsénico de origen natural, encontrados en algunos pozos de agua potable de los municipios de Araró y Cuitzeo en el estado de Michoacán, son un problema que causa preocupación ya que pone en riesgo la salud humana de las comunidades existentes en dicha zona. Por lo tanto, es necesario desarrollar métodos de remediación que permitan disminuir la concentración de arsénico del agua que se extrae de los mantos acuíferos contaminados con dicho elemento; para esto es importante que la investigación esté orientada a buscar alternativas para la remoción de arsénico empleando materiales que sean de fácil adquisición, bajo costo, un ejemplo de esto son los residuos agroindustriales y las diferentes biomasas fúngicas. El objetivo de esta investigación fue evaluar la capacidad de adsorción de arsénico en soluciones acuosas de tres tipos de biomasas diferentes: residuos de limón, biomasas muerta del hongo Trichoderma atroviride y una biomasa mixta compuesta por el crecimiento de dicho hongo sobre los residuos de limón. Las biomasas se acondicionaron, y se caracterizaron por medio de análisis químicos para determinar el tipo de componentes mayoritarios que cada una de estas presentaba, posteriormente se realizaron análisis de FT-IR así como de MEB para conocer la morfología de cada uno de las biomasas utilizadas. Se realizaron experimentos de contacto tipo lote y los sobrenadantes se analizaron por AA-GI y se ajustaron a los respectivos modelos empíricos. Los resultados obtenidos demuestran que en todas las biomasas se presenta una sorción del tipo química, la biomasa que presenta la mayor capacidad de sorción fueron los residuos de limón siendo aproximadamente 2 veces mayor que las otras biomasas probadas. Concluyendo que para este tipo de biomasa mixta la remoción no es tan eficiente como lo es si se usan las biomasas por separado.

Instituto de Investigaciones Agropecuarias y Forestales. Facultad de Biología. Facultad de Medicina Veterinaria y Zootecnia. Facultad de Agrobiología. Facultad de Químico Farmacobiología. Programa Institucional de Maestría en Ciencias Biológicas Suffering severe pollution affects the Lerma river sediment conditions, water and living organisms have deteriorated causing a decline in their quality, alteration of food webs and disappearance of aquatic organisms. Assessment was made of heavy metals in water and sediments in the bend of the river Lerma meander in La Piedad, Michoacán, studying the spatial and temporal dynamics of metals, we identified the sites that exceed international standards and recommended level of contamination. Heavy metals are harmful to health and the ecosystem due to their persistence and toxicity. Also, there are few studies of its kind in the Lerma basin, especially in the State of Michoacan, is little information on heavy metals and arsenic in water and sediment in the study area. In 2009, the results indicate a drought year, with little depth in dry spells and rainfall (less than 1 m). Physiochemical parameters, only dissolved oxygen showed statistically significant variations between sites and do not represent differences in the characteristics of water in the studied sites. Were detected in water concentrations of zinc and arsenic in all samples taken and the statistical tests indicate differences and similarities between rainfall and drought. Was performed the physical characterization of sediments and heavy metals were determined Cr, Ni, Cu, Zn and Pb by X- ray fluorescence (XRF) and Fe and As by atomic absorption spectrophotometry (AAS). Debido a la contaminación que sufre el río Lerma, las condiciones del sedimento, del agua y organismos vivos se han deteriorado provocando una disminución de su calidad, alteración de las cadenas tróficas y desaparición de organismos acuáticos. En este trabajo se realizó una evaluación del contenido de metales pesados en agua y sedimentos en el meandro del río Lerma en La Piedad de Cabadas, Michoacán, donde se definió la dinámica especial y temporal de los metales en estos componentes, estableciendo los sitios que exceden los criterios internacionales recomendados y su nivel de contaminación. La importancia de analizar metales pesados radica en que estos resultan dañinos a la salud y el ecosistema debido a su persistencia y toxicidad. Es importante recalcar que existen pocos estudios de este tipo en la cuenca del Lerma, en especial en el Estado de Michoacán y es escasa la información de metales pesados y arsénico en agua y sedimento en la zona de estudio. Con base en los resultados obtenidos y análisis realizados, el año 2009 se considera un año de sequía, la poca profundidad mostrada en temporadas de estiaje y precipitación pluvial no rebasó el metro de profundidad, en cuanto a parámetros fisicoquímicos, solo el oxígeno disuelto mostró variaciones estadísticas significativas entre sitios y no representan diferencias en las características de agua de los sitios estudiados. Se detectaron concentraciones en agua de zinc y arsénico en todos los muestreos realizados en los ocho sitios y los resultados de las pruebas estadísticas indican diferencias y similitudes entre precipitación pluvial y estiaje. A las muestras de sedimento se les realizó una caracterización física y se determinaron los metales pesados Cr, Ni, Cu, Zn y Pb por fluorescencia de rayos X (FRX) y Fe y As por espectrofotometría absorción atómica (AAS).