Use of glycosides extracted from the fique (<Emphasis Type="Italic">Furcraea</Emphasis> sp.) in wastewater treatment for textile industry     

W. A. Lozano-Rivas  K. E. Whiting  C. Gómez-Lahoz  J. M. Rodríguez-Maroto 《International Journal of Environmental Science and Technology》2016,13(4):1131-1136

The laboratory tests for the use of sapogenic amphiphilic glycosides as a coagulation–flocculation aid are presented in this paper. These amphiphilic glycosides were obtained, through a natural fermentation process, of the juice, of fique (Furcraea sp.) leaves. Decantation allows for the separation of a supernatant denominated “supernatant fique juice” and a decanted fraction denominated “decanted fique juice.” The latter contains most of the sapogenic amphiphilic glycosides and was mixed with the chemical coagulant ferric chloride hexahydrate, at varying doses. Ferric chloride hexahydrate was also used as a control to ascertain the removal efficiency of persistent contaminants from samples of a textile industry effluent. The parameters of interest were typical indicators of water quality such as color, turbidity, chemical oxygen demand, pH and conductivity. The results indicate that the decanted fique juice, when used as a coagulation–flocculation aid, and upon comparison with the chemical coagulant alone, causes an additional color and turbidity reduction of 31 and 17 %, respectively. No significant differences were noted in the chemical oxygen demand values (α = 0.05; P < 0.001). Thus, there is a scope for further research about the commercial feasibility of DFJ as an industrial water treatment agent, which reduces the toxicity of raw fique juice and its detrimental environmental effects.  相似文献   

Metal concentrations in sediments from tourist beaches of Huatulco,Oaxaca, Mexico: an evaluation of post-Easter week vacation     

I. Retama  M. P. Jonathan  Priyadarsi D. Roy  P. F. Rodríguez-Espinosa  R. Nagarajan  S. K. Sarkar  S. S. Morales-García  N. P. Muñoz-Sevilla 《Environmental Earth Sciences》2016,75(5):375

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Solid phases controlling the mobility of potentially toxic elements and the generation of acid drainage in abandoned mine gold wastes from San Antonio–El Triunfo mining district,Baja California Sur,México     

Ernesto Hernández-Mendiola  Francisco Martín Romero  Margarita Gutiérrez-Ruiz  Carlos Alberto Magdaleno Rico 《Environmental Earth Sciences》2016,75(11):969

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Efficiency of calcein tagging on juveniles of the sea urchins Diadema africanum and Paracentrotus lividus          下载免费PDF全文

Adriana Rodríguez  José Carlos Hernández  Sabrina Clemente 《Marine Ecology》2016,37(2):463-469

We evaluated the effectiveness of chemical tagging with the fluorescent marker calcein for two key species of herbivorous sea urchins, Diadema africanum and Paracentrotus lividus, to facilitate medium‐ and long‐term ecological experiments. In total, 98 juveniles of D. africanum and 98 P. lividus were tagged with this fluorescent marker, with 12 combinations of different tagging techniques (chemical bath or injection), concentrations of calcein (2, 10 and 20 mg · l^?1), and soaking times (2, 4 and 24 h). Respective control treatments were conducted by means of seawater injection and bathing. The success of tagging was assessed after a month of feeding individuals ad libitum with the algae Dictyota sp. Sea urchins were dissected and their Aristotle's lanterns cleaned with 10% sodium hypochlorite to examine these structures under UV light using a binocular microscope. Each species was evaluated in terms of survival, percentage of tagged individuals and intensity of the resulting tag. The results showed that the method of soaking individuals of both species for 24 h in concentrations of calcein of 10 and 20 mg · l^?1 gave the highest percentage survival (100%) and the resulting tags were clearly visible.  相似文献   

A methodology to estimate seismic vulnerability of health facilities. Case study: Mexico City,Mexico     

Sonia Morán-Rodríguez  David A. Novelo-Casanova 《Natural Hazards》2018,90(3):1349-1375

We developed a model to estimate seismic vulnerability of health facilities in Mexico City, Mexico, following these steps: (1) designing a theoretical framework (TF) to measure structural, non-structural, functional, and administrative-organizational vulnerabilities; (2) measurement of the vulnerability conditions of the analyzed facility by using the TF; and (3) estimation of the hospital’s seismic vulnerability by comparing the measured vulnerability to the TF’s vulnerability indicators by taking into account the optimal case. The TF was developed considering a scoring system and international standards for risk management in hospitals. The methodology establishes the degree of vulnerability of the analyzed institution as well as its interrelations with external infrastructure systems. This tool also identifies existing failures to estimate expected damage. The methodology was applied to the National Cardiology Hospital, the Children’s Hospital “Dr. Federico Gómez,” and the “Hospital de Jesus” of Mexico City. The vulnerability problems in these three hospitals are common within them, and some of the main causes of vulnerability found are: (1) the lack of technology to resistant seismic shaking; (2) the need to develop or update disaster response plans; (3) the need of periodic and proper maintenance to hospitals’ buildings; (4) the lack of sufficient financial resources for vulnerability reduction projects and autonomous operations of the hospital during 3–5 days after a disaster occurs. We believe that vulnerability in these health facilities can be reduced with low-cost procedures and that the methodology developed here will support the decision-making processes to reduce seismic risk in Mexico City.  相似文献   

Reducing leachable petroleum hydrocarbon concentration in weathered fuel oil contaminated soil by chemical oxidation with hydrogen peroxide     

E. Romero-Frasca  R. H. Adams  V. I. Domínguez-Rodríguez 《International Journal of Environmental Science and Technology》2018,15(11):2381-2388

Number 6 fuel oil is one of the most used energy sources for electricity generation. However, leaks can contaminate soil and also groundwater due to leaching. At old sites, the oil may have low toxicity but still contaminate groundwater with foul-tasting compounds even at low concentrations. The purpose of this study was to evaluate the feasibility of applying H₂O₂ to reduce the leaching potential of a fuel oil contaminated soil. A silt-loam soil was collected from a contaminated thermal-electric plant with a hydrocarbon concentration of 3.2% in soil producing 4.3 mg/l in leachate. Hydrogen peroxide was applied (0.1, 0.2, 0.3, 0.6, 1.2% dry weight basis), and petroleum hydrocarbons were measured in soil and leachate pre- and post-treatment (72 h). At first, the soil and leachate concentrations diminished linearly (24.4 and 27.3% in soil and leachate, respectively). This was followed by a phase in which the concentration in leachate diminished greatly (75.8%) although the concentration in soil was reduced only moderately (15.1%). Overall, hydrocarbons in leachates were reduced 82.4% even though concentrations in soil were only reduced 35.8%. Correlation analysis showed that at only 1.0% w/w H₂O₂ a concentration of petroleum hydrocarbons in leachate safe for human consumption (≤ 1 mg/l) could be obtained even with a final hydrocarbon concentration in soil > 2%. Thus, this study presents an alternative strategy for remediation of fuel oil contaminated soils in urban environments that protects water sources by focusing on contamination in leachates, without spending extra financial resources to reduce the hydrocarbon concentration in low-toxicity soil.  相似文献   

The opening of the Magellan Strait and its geodynamic implications     

Matías C. Ghiglione  Angela Teresa Navarrete‐Rodríguez  Mauricio González‐Guillot  Gustavo Bujalesky 《地学学报》2013,25(1):13-20

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The Homo habitat niche: using the avian fossil record to depict ecological characteristics of Palaeolithic Eurasian hominins     

Clive Finlayson  José Carrión  Kimberly Brown  Geraldine Finlayson  Antonio Sánchez-Marco  Darren Fa  Joaquín Rodríguez-Vidal  Santiago Fernández  Elena Fierro  Marco Bernal-Gómez  Francisco Giles-Pacheco 《Quaternary Science Reviews》2011,30(11-12):1525-1532

Although hardly applied to human palaeoecology, bird fossils offer a unique opportunity for quantitative studies of the hominin habitat. Here we reconstruct the Homo habitat niche across a large area of the Palaearctic, based on a database of avian fauna for Pleistocene sites. Our results reveal a striking association between Homo and habitat mosaics. A mix of open savannah-type woodland, wetlands and rocky habitats emerges as the predominant combination occupied by Homo across a wide geographical area, from the earliest populations of the Lower Palaeolithic to the latest hunter-gatherer communities of the Upper Palaeolithic. This observation is in keeping with the view that such landscapes have had long standing selective value for hominins.  相似文献   

Polycyclic aromatic hydrocarbons (PAHs), organic matter quality and meiofauna in Galician sandy beaches, 6 months after the Prestige oil-spill     

Rodríguez JG  Incera M  de la Huz R  López J  Lastra M 《Marine pollution bulletin》2007,54(7):1046-1052

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The August 20, 1852 earthquake in Santiago de Cuba     

Mario Octavio Cotilla Rodríguez  Diego Córdoba Barba 《Russian Geology and Geophysics》2010,51(11):1227-1246

On August 20, 1852, an earthquake caused widespread destruction in the city of Santiago de Cuba and its surroundings. A comprehensive search for contemporary documentation was made. The information gathered was used for a detailed analysis of the damage from and characteristics of the earthquakes. Intensities were evaluated at 45 localities, and an isoseismal scheme has been drawn. Maximum intensity reached 8 degrees (MSK), and 6.4 was the estimated magnitude. Damage to the city of Santiago de Cuba has been studied in detail. The low quality of construction aggravated the damage. The total number of casualties was two dead and approximately 200 injured. The shock was felt within 80,000 km². The epicenter was determined as 19.75º N, 75.32º W, h = 30 km. This study shows that contemporary Cuban documents must be studied with care in their historical and cultural background to avoid overestimating earthquake intensities.  相似文献