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Sosa-Villalobos C.A.,Technological Institute of Boca del Rio | Rustrian E.,University of the East of Mexico | Houbron E.,University of the East of Mexico
International Journal of Environmental Research | Year: 2015

The Cane alcohol vinasse assessment on the removal efficiency of a fixed biomass anaerobic reactor (FBAR) was evaluated. Crude vinasse was used to feed the reactor. The FBAR was operated with organic load rate (OLR) of 0.5, 1, 3 and 6 gCOD/L/d. Removal efficiencies of 85, 82, 75 and 66 per cent were observed respectively. The FBA reactor presented an excellent removal of organic matter, however, when more than OLR of 3 gCOD/L/d, an unexpected behavior began, it reduced its capacity. The average biogas production was 1.925, 2.613, 5.653 and 8.290 L for OLR of 0.5, 1, 3 and 6 gCOD/L/d respectively. The methane content in biogas was 56, 79, 89 and 82 per cent, in each OLR tested. Methane production was 1.070 L for an OLR 0.5 gCOD/L/d, 2.070 L on an OLR of 1 gCOD/L/d, 5.046 L with OLR of 3 gCOD/L/d and 6.800 L to OLR of 6 gCOD/L/d. Methane performance was used as monitoring parameter, this parameter gives information of the value between the catabolic activity (methane production) and the anabolic activity (bio-film production). The averageYCH4, valueswere 0.304, 0.302, 0.306 and 0.205 LCH4/gCODremoved, respectively. The thermoplastic support inoculated in the FBA reactor and fed with crude vinasse, acted as a filter, plus getting good results in removal of chemical oxygen demand (COD), but because of the size and height of the filling, the methane evacuation stopped. © 2015, University of Tehran. All rights reserved. Source


Ek-Huchim J.P.,National Polytechnic Institute of Mexico | Jimenez-Garcia I.,Technological Institute of Boca del Rio | Perez-Vega J.A.,National Polytechnic Institute of Mexico | Rodriguez-Canul R.,National Polytechnic Institute of Mexico
Diseases of Aquatic Organisms | Year: 2012

Infection of Nile tilapia Oreochromis niloticus by monogeneans of the genus Cichlidogyrus is harmful. Currently, diagnosis of this infection is based on invasive techniques and the identification of isolated parasites by their morphology. To facilitate diagnosis, we have developed a non-lethal polymerase chain reaction (PCR) test for detection of Cichlidogyrus spp. DNA in the gill mucus of O. niloticus, using 5 pairs of specific primers based on Cichlidogyrus sclerosus 28S rRNA (Cicly 1 to Cicly 5) which generate fragments of approximately 188, 180, 150, 159 and 189 bp, respectively. PCR specificity was tested using genomic DNA extracted individually from 175 isolated Cichlidogyrus spp., 75 Gyrodactylus cichlidarum and 75 endopararasitic Entero-gyrus spp., as well as from 75 protozoans Trichodina spp. The Cicly primers were used to detect Cichlidogyrus spp. DNA in mucus from the gills of 23 Nile tilapia confirmed to be infected with the parasite. Negative controls consisted of 45 uninfected Nile tilapia. The limit of sensitivity of the assay was 1.2 ng of purified parasite DNA. The Cicly primers did not amplify DNA from the mucus of non-infected Nile tilapia, G. cichlidarum, Trichodina spp. or Enterogyrus spp. In all cases, the sensitivity and specificity of the test were 100%. The sequences of all the amplified fragments showed a high similarity to that of the 28S rRNA region of C. sclerosus (93 to 100% identical to GenBank Accession No. DQ157660.1). We provide evidence for a safe and noninvasive DNA-based diagnostic method for the presence of Cichlidogyrus in the gill mucus of O. niloticus. © Inter-Research 2012. Source


Salgado-Maldonado G.,National Autonomous University of Mexico | Caspeta-Mandujano J.M.,Autonomous University of the State of Morelos | Moravec F.,Academy of Sciences of the Czech Republic | Soto-Galera E.,National Polytechnic Institute of Mexico | And 3 more authors.
Parasitology Research | Year: 2011

An inventory based on previously published records and original data is presented for the helminth parasites reported in 54 fish species from 17 families from the state of Chiapas, southeast Mexico. This survey reports the presence of 43 helminth species in Chiapas for the first time. The actualized inventory of helminth parasites of freshwater fish from Chiapas contains 88 species from 67 genera and 40 helminth families. Trematodes and nematodes were the most abundant taxonomic groups. The helminth fauna in freshwater fishes from Chiapas consists of Central American species. All the helminth species recorded in Chiapas have also been collected from bodies of freshwater between the Isthmus of Tehuantepec and the Isthmus of Panama. This inventory shows that this fauna is quite similar to that from the neighboring basins of the lower Grijalva-Usumacinta system and the Yucatan Peninsula. The taxonomic composition and distribution data reported here for the helminth fauna of Chiapas' freshwater fish, contribute to a better understanding of this faunal component in Central America. © 2010 Springer-Verlag. Source


Lopez-Naranjo E.J.,Research Center Cientifica Of Yucatan | Alzate-Gaviria L.M.,Research Center Cientifica Of Yucatan | Hernandez-Zarate G.,Technological Institute of Boca del Rio | Reyes-Trujeque J.,Autonomous University of Campeche | And 2 more authors.
Journal of Applied Polymer Science | Year: 2013

Wood-plastic composites (WPCs) are considered to be highly durable materials and immune to any type of biological attack. However, when one of these composites is exposed to accelerated weathering, its surface is affected by the appearance of cracks, which constitute an ideal access route for biotic agents. Although the destruction of wood caused by termites is recognized worldwide, information on their effects on WPC-based products is scarce. Thus, in this study, we aimed to examine the effects of termite attacks on weathered and nonweathered pinewood residue/recycled high-density polyethylene composites. In this study, WPCs with 40 wt % wood were prepared. Test samples obtained by compression molding and profile extrusion were subjected to weathering cycles for 1000 and 2000 h with a UV-type accelerated tester equipped with UVA-340 fluorescent lamps. Afterward, specimens were exposed to the attack of higher termites (Nasutitermes nigriceps) native to the Yucatan Peninsula. Subsequently, flexural mechanical essays, Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) analyses were performed. FTIR spectroscopy and DSC showed that the surfaces of the compression-molded specimens were degraded to a higher extent because of the accelerated weathering. The microscopy results revealed that severe damage was caused by the termites on the surface of the compression-molded samples. Statistical analysis of the mechanical test results showed that biotic attack produced significant changes in the samples previously exposed to accelerated weathering. The results show that the processing method directly affected the sample performance because of differences in the surface composition. The profile-extruded composites seemed to better resist termite attack. © 2012 Wiley Periodicals, Inc. Source


Espana-Gamboa E.,Research Center Cientifica Of Yucatan cy | Barahona-Perez L.,Research Center Cientifica Of Yucatan cy | Dominguez-Maldonado J.,Research Center Cientifica Of Yucatan cy | Hernandez-Zarate G.,Technological Institute of Boca del Rio | Alzate-Gaviria L.,Research Center Cientifica Of Yucatan cy
Waste Management and Research | Year: 2011

The final products of the ethanol industry are alcoholic beverages, industrial ethanol and biofuels. They are produced by the same production process, which includes fermentation and distillation of raw materials which come from plant biomass. At the end of the distillation process a waste effluent is obtained called vinasse or stillage. The direct disposal of stillages on land or in groundwater (rivers, streams or lakes), or even for the direct irrigation of crops, pollutes the environment due to their high organic contents, dissolved solids and many other compounds which are toxic or could be contaminants under certain environmental conditions. This work reviews the characterization of vinasses from different feedstock sources and the main treatments for conditioning the soluble solids of vinasses before their disposal. © 2011 International Solid Waste Association. Source

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