El elevado volumen de uso a nivel nacional e internacional, la baja degradabilidad, la potencial bioconcentración y la toxicidad de los detergentes han motivado la búsqueda de técnicas de tratamientos oxidativos avanzados que permitan mineralizar las moléculas del agente tensoactivo de los detergentes a sustancias menos contaminantes. El dodecilbencensulfonato de sodio es una molécula del tipo lineal alquilbencensulfonato (LAS), es uno de los principales agentes tensoactivos de los detergentes comerciales usados actualmente, ello motivó que los ensayos de degradación en este trabajo se realizaron sobre esta molécula. Además se utilizaron muestras reales de efluentes de lavandería doméstica y de lavandería tipo industrial. El sistema utilizado para lograr la degradación de LAS es el H₂O₂/TiO₂/UV, en un reactor de lecho fluidizado. La caracterización del catalizador se ...

El elevado volumen de uso a nivel nacional e internacional, la baja degradabilidad, la potencial bioconcentración y la toxicidad de los detergentes han motivado la búsqueda de técnicas de tratamientos oxidativos avanzados que permitan mineralizar las moléculas del agente tensoactivo de los detergentes a sustancias menos contaminantes. El dodecilbencensulfonato de sodio es una molécula del tipo lineal alquilbencensulfonato (LAS), es uno de los principales agentes tensoactivos de los detergentes comerciales usados actualmente, ello motivó que los ensayos de degradación en este trabajo se realizaron sobre esta molécula. Además se utilizaron muestras reales de efluentes de lavandería doméstica y de lavandería tipo industrial. El sistema utilizado para lograr la degradación de LAS es el H₂O₂/TiO₂/UV, en un reactor de lecho fluidizado. La caracterización del catalizador se ...

Universidad Nacional Agraria La Molina. Escuela de Posgrado. Doctorado en Ingeniería Ambiental

In this study the degradation of polycyclic aromatic hydrocarbons (PAHs) present in waste street sweeping by aerobic treatment was assessed using four different samples of compost quality. It was possible to reduce the concentration in the samples ƩHAPs reaching removal rates of greater than 80% within 120 days of aerobic treatment, samples of compost with anaerobic pretreatment promote further degradation of PAHs reaching higher removals than 90%, this may influenced by the presence of microorganisms capable of degrading organic matter and humic substances produce. The toxic effect evaluated as BaPeq is reduced by over 66% in the first 30 days of treatment for waste shows similar percentages sweep streets can be achieved in more than 90 days of treatment. The ecotoxicological effects assessed on Daphnia magna and Lactuca sativa, indicate that PAH metabolites being produced cometaboliza...

In this study, waste hairs of the enzymatic unhairing process (PPE) of tannery were used as adsorbents to remove lead of a solution. Waste hairs were treated with acid hydrolysis and used in the type batch adsorption experiments, to be examined the effect of pH on the adsorption and also to investigate the mechanism of adsorption for which studies adsorption isotherms and the adsorption kinetics of Pb (II) were performed on treated hairs. The results showed that adsorption of Pb (II) was pH dependent with the optimum pH of 7. Isotherm studies showed that experimental data match the pattern of the Langmuir isotherm for the case of treated hairs of the enzymatic unhairing process (PTPE). The maximum adsorption capacity was 321.20 mg Pb (II)/g of bioadsobent (PTPE). The kinetic studies showed that the reaction model of pseudo-second order best describes the adsorption process. Finally, the ...

The objective of this research was to identify the functional groups that are responsible for the adsorption of Pb (II) on the treated hair residues of the enzymatic unhairing process of the tanneries. For this purpose was made the preparation of adsorbent, which consisted in washing hair residues in order to deliming and lower the pH of 12 to neutral, after which they were dried and was applied these the treatment of acid hydrolysis, at the end of which these were washed, dried and ground. Then the hairs treated with the Pb (II) solution were placed in agitation in a range of time and pH, for the study of adsorption isotherms and the kinetic study. At the end of which a chemical characterization was carried out through the FTIR analysis and the XRD analysis. Thus also a physical characterization with a SEM analysis, by means of two detectors of the equipment. These analyses were carried...

In this work the toxic and ecotoxicological effect of black sand (ANM) from artisanal gold extraction in the department of Madre de Dios was studied. Toxicity Characteristic Leaching Procedure (TCLP) was used to evaluate the toxic effect and with the leachates,acute ecotoxicity tests were performed according to EPA protocol 600 / 3-88 / 029 using test microorganisms, Daphnia Magna neonates , with 24 hours of birth and in seeds of Lactuca Sativa. The quantification of total mercury in ANM samples and in leachates was performed by Inductively Coupled Plasma Atomic Emission Spectroscopy. The values obtained of total mercury in the ANM samples were in the range of 0.1 and> 275 mg/kg of black sand indicating that they exceed the background values by 1000 times. In the leachates the total mercury concentration was in the range of 0.001 and> 2.75 mg/L, some of these values exceed the maxi...

The present study evaluated the hydrolysis of rice husk, by means of alkaline peroxide, acid peroxide and silicate peroxide pretreatment, followed by enzymatic hydrolysis using cellulases, with a high level of β-glucosidases and hemicellulases. Pretreatments were performed by varying the concentrations of the alkaline medium (0, 2, 4 and 6 % p/v), acid (0, 5, 10 and 15 % v/v) and silicates (0, 5, 10 and 15 % v/v) in varying concentrations of peroxide (0, 5, 10 and 15 % v/v). Enzymatic hydrolysis was performed at 50 °C, pH 5, 72 h, 0.3 mL of enzyme per g of husk, with a load of 5 % w/v. The morphological characterization of the surface of the rice husk by means of the SEM presented a greater transformation in alkaline-peroxide medium. The concentration of reducing sugars after the alkaline peroxide pretreatment (6 % KOH – 15 % H2 O2 , pH 11, 70 °C, 3 h and with a load 10 % p/v) and t...

El presente estudio tuvo como objetivo analizar mediante el método de análisis por componentes principales (ACP), la influencia de los parámetros de diseño de la metodología de explosión de vapor sobre la remoción de lignina y variación de otras propiedades físicas en la cascarilla de arroz, residuo agrícola de amplio interés para la producción de etanol 2G. Mediante este proceso se facilita el acceso de enzimas en la hidrólisis de la celulosa. Del análisis se encontró que la presión y el factor de severidad (FS), parámetros del proceso explosión de vapor, se relacionan estrechamente con el pH del lixiviado y la cantidad remanente de lignina en la cascarilla, debido principalmente a la formación de ácidos débiles, autohidrólisis y reacciones de despolimerización - repolimerización de la lignina. Adicionalmente se encontró que otros parámetros como la humedad y l...

Traditional methods of leather production in Peru consume on average between 60 to 80% of chromium for tanning process , generating wastewater with high concentrations of total chromium that must be treated in order to meet the Maximum Allowable Values ( VMA ) established by the DS 029-2009 - Vivienda. The use of complexing agents in the chrome tanning process reduces the supply of chromium to increase skin absorption. The main objective of this study was to evaluate the treatability by chemical precipitation of wastewater from traditional and alternative tanning process. It was determined that the optimal pH for the precipitation was between 7.36 and 9.99, the doses used besides sodium hydroxide were between 0.5 and 5.5 g / L, is the traditional process that requires higher dose . It was determined that the cost of the inputs used in the production of wet blue leather is more than the c...

The present study evaluated the removal of lignin from the rice husk, by means of steam explosion at different severity conditions. The process of lignin removal was evaluated as lignin Klason was performed in samples with pretreatment at pressures of 0.4; 0.6; 0.8 and 1.0 MPa, times of 6, 8, 10 and 12 minutes with a decompression of between 5 to 7 seconds; it is a lignin removal from 18.02 % up to 12.7 % at 1.0 MPa and 12 min compression, factor of 3.3 severity. The evaluation by FTIR of the husk without pretreatment, with pretreatment at 0.4 MPa and 12 min, 1.0 MPa and 12 min, shows a reduction in the transmission generated by the peaks corresponding to the presence of lignin -OH (2920 cm-1 ), CH and CO (1320 and 1360 cm-1), COC a (1060 cm-1) among others. The promover per screening electronic microscopy (SEM) showed the degree of introducción Sud cantidades of the surface of the rice...

In the present study, the stabilization of horse manure (mixture of rice husk, manure and horse urine) was evaluated through an aerobic process similar to composting. The stabilization process was evaluated in two piles of horse manure for 16 weeks, taking samples every week. A decrease in temperature from 66,7 to 41,0 °C, the reduction of the density from 394,0 to 370,4 kg/m3, the reduction of the water retention capacity from 220,7 to 125,6% and the reduction of the respiratory activity of 9.8 to less than 2 mgO2/g ms/d, were indicators of the stabilization of the horse manure, the easily degradable material of manure and urine were removed by aerobic degradation and washed with irrigation, leaving only the rice husk with a minimum fraction of other materials. On the other hand, the increase in total nitrogen and a decrease in the C/N ratio at the end of the week 16 were indicative of...