A filter made of a nanocomposite of clay – carboximethylchitosan – silver nanoparticles was created to eliminate bacteria and anions in water for human consumption. The silver nanoparticles were obtained by reduction of silver nitrate 1mM, with carboximethyl chitosan at 0.01% and sodium borohydrido 2mM as starter of the reduction. Then the clay filters were made with wood sawdust as the pore maker in a 2:1 proportion; it was molded, dried and sinterized at 800°C for 3 hours. Quickly the filters were impregnated with the colloidal dispersion of carboximethyl chitosan – silver nanoparticles by immersion for 12 hours. Four water sampling points were defined: Huacapuy, La Punta, Plaza de Quilca, Caleta de Quilca. When evaluating the filtering capacity of the filters, it was found that the following were removed: conductivity 84.03% in La Plaza de Quilca, sulfates 85.48% in La Plaza de...

El deterioro de las construcciones hechas con ignimbrita en el centro histórico de Arequipa, es un problema causado por el intemperismo, emisión de contaminantes industriales y biológicos, afectando su preservación. Se evaluó aplicar a la ignimbrita, polisiloxano funcionalizado con nanopartículas de plata (PXS-AgNPs), como recubrimiento para disminuir su porosidad, evitar su degradación y darle un efecto protector a su superficie.Las nanopartículas de plata (AgNPs) se sintetizaron, por reducción de nitrato de plata (AgNO3) con borohidruro de sodio (NaBH4), el polisiloxano se sintetizó por hidrólisis del clorosilano en agua y éter dietílico; que fue funcionalizado con AgNPs, mezclando soluciones acuosas de PXS y de AgNPs, obteniéndose un gel de color amarillo lechoso. Se aplicó PXSAgNPs a la superficie de la ignimbrita y se realizaron pruebas de adsorción con solución de ...

The O-carboxymethylchitosan (O-CMQ) was derivatized from the chitosan copolymer by the direct alkylation method. This method involved the reaction of the chitosan with monochloroacetic acid after alkalinization. The derivatized product showed solubilityin a pH range of 1-13 and low solubility at pH = 5. The degree of substitution (GS) was 0,92, determined by conductometric titration. The results of Fourier Transform Infrared Spectroscopy (FT-IR) allowed us to identify a strong intensity absorption band at 1585cm-1, corresponding to the stretching of C = O, which indicates the presence of a carboxylic anion (-COO- ) that is characteristic of O-carboxymethylchitosan (O-CMQ). Using the Nuclear Magnetic Resonance spectroscopy of proton and carbon-13 (1 H NMR, 13C NMR) showed that the substitution was carried out on carbon 3 and 6 of chitosan. The derivatized O-CMQ at concentration of 50mg / ...

The objective of this study was to evaluate the physicochemical treatment of wool washing effluents from a textile industry in the city of Arequipa in order to comply with the Maximum Admissible Values (VMA), using 40% ferric trichloride as coagulant and 0,1% MT-FLOC 4299 polymer flocculant. The effluent was physically and chemically characterized at the beginning and at the end of the treatment, measuring pH, temperature, Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), total suspended solids (TSS), oils and fats, sulfates, ilosulphides, ammoniacal nitrogen, total cyanide, hexavalent chromium and turbidity. To determine the optimal doses of coagulant and flocculent, three treatments were done using a jug set at 50, 200 and 40 rpm. The sedimentation time of the floc was 10 minutes. The initial turbidity ranges oscillated between 200 and 800 NTU, obtaining a removal of 89 % ...

In the present investigation we present a polysiloxane composite functionalized with silver nanoparticles (NPs-Ag). NPs-Ag was synthesized, by reduction of a silver nitrate solution (AgNO3) with sodium borohydride (NaBH4), the NPs-Ag were characterized by the UVvisible spectrophotometric method, finding that between 400 - 410 nm the typical peak of NPs-Ag by surface plasmon resonance. In the Dynamic Light Scattering (DLS) analysis of the NPs-Ag, a polydisperse distribution was found with two populations of 59.78 nm in 70% and 4.33 nm in 30%. Subsequently, the polysiloxane gel was synthesized by hydrolyzing chlorosilane, using diethyl ether as the solvent, the obtained polysiloxane was characterized by infrared Fourier transform spectrophotometry (FTIR). In the spectrum peaks are observed in the region of 1258.88 cm-1 corresponding to methyl, between 1000 - 1100 cm-1 a peak corresponding ...

The synthesis of the nanocomposite based on silver nanoparticles and O-carboxymethyl chitosan (NPsAg-CMQ), by the chemical reduction method, using the O-carboxymethylchitosan 0.01% and AgNO3 1 mM in a ratio of 3: 2, with a time of 30 minute reaction, at room temperature and neutral pH. The nanocomposite obtained from the complex [Ag(NH3)2]+ was synthesized under the same conditions as AgNO3 but at a basic pH. Using UV-VIS spectrophotometry, the plasmon formation of silver nanoparticles at 410nm was verified for both silver sources. The results by Dynamic Light Dispersion (DLS) for AgNO3, shows a monodisperse distribution of the nanocomposite with an average hydrodynamic size of 166.7 nm. In the case of the diamine silver [Ag(NH3)2] + 83.9% had an average size of 54.42 nm. and 15.2% of 4.48 nm. Infrared Spectroscopy Measurements with Fourier Transform (FT-IR) shows the inhibition of the s...

Objective: The current study’s objective is to characterize a new throm-bin-like enzyme called TLBro that was obtained from Bothrops roedingeris snake from a biochemical and hemostatic perspective. Methodology: One chromatographic step was used to purify it, producing the serine protease TLBro. Molecular mass was estimated by SDS-PAGE to be between reduced and unreduced by 35 kDa. Tryptic peptide sequencing using Swiss Prot provided the complete amino acid sequence. Expasy.org by conducting a search that is limited to Crotalinae snake serine proteases and displaying a high degree of amino acid sequence. Results: Ser (182) is inhibited by phenylmethylsulfonyl fluoride (PMSF), and TLBro demonstrated the presence of Asp (88) residues. It also deduced the positions of His (43) and Ser (182) in the set of three coordinated amino acids in serine proteases. It was discovered that this substra...