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Resumen En la industria petrolera se almacenan grandes cantidades de hidrocarburos en tanques en las diferentes etapas de extracción y procesamiento del crudo hasta su refinamiento. Esto genera un residuo denominado fondo de tanque, es una emulsión estable de sedimentos agua e hidrocarburos. Este trabajo tuvo como objeto estudiar las bacterias que están presentes en el sedimento después de la primera etapa de tratamiento con gasoil, agua, temperatura y posterior centrifugación. El sedimento, considerado por la legislación como residuo peligroso se le realizo un estudio bacteriológico, que consistió en recuento, aislamiento e identifican de bacterias. Se obtuvieron 34 cepas de las cuales 86.1% pertenecieron al género Bacillus. Las mismas presentaron capacidad para desarrollar en alguno de los siguientes hidrocarburos o mezclas de hidrocarburos gasoil, kerosene, hexadecano y ciclohexano.
Abstract In the oil industry, large quantities of hydrocarbons are stored in tanks, in the different stages of extraction and processing of crude oil until it is refined. This generates a residue called a tank bottom, which is a stable emulsion of water and hydrocarbon sediments. The objective of this work was to study the bacteria that are present in the sediment after treating the bottom of the tank with diesel oil, water, and subsequent centrifugation. A bottom and tank were treated with diesel, water and centrifugation, the sediment was obtained, which was counted, isolated and bacteria were identified. 34 strains were obtained, of which 86.1% belonged to the genus Bacillus. The same capacity capabilities to develop diesel, kerosene, hexadecane, and cyclohexane hydrocarbons.
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Aims@#Water is described as safe and wholesome when it is free from pathogenic microorganisms and chemical substances that are hazardous to human health. This study aimed to investigate the microbial quality of water used for drinking, cooking, bathing and other purposes at universities in Nigeria.@*Methodology and results@#Water samples were collected from forty-four storage tanks across four selected universities. Total viable bacteria in the water samples were cultivated using the plate count agar. The isolation of total coliform and Escherichia coli were carried out on Harlequin™ E. coli/coliform agar (HA) medium, while media-faecal coliform was used for faecal coliform employing the membrane filtration technique. Physicochemical parameters such as alkalinity, pH, total alkalinity, total dissolved solid, total suspended solid, electrical conductivity, total hardness, fluoride and chloride ion concentrations, were evaluated in accordance with standard procedures. Data were compared statistically using MedCalc statistical software. Considering the heterotrophic bacterial counts, all water samples were unsatisfactory. For the total coliform counts, 50% of samples were satisfactory but suspicious, while remaining 50% were unsatisfactory. Faecal coliforms results showed that 50% of samples gave excellent quality, 25% showed satisfactory but suspicious quality, while 25% showed unsatisfactory result. There were no significant differences in the total viable, total coliform and E. coli counts of water sampled from universities A and D (p>0.05). The predominant bacterial species was Pseudomonas aeruginosa (23.17%), while the least encountered was Salmonella typhimurium (2.44%). All physicochemical parameters tested were within the acceptable limit.@*Water samples were collected from forty-four storage tanks across four selected universities. Total viable bacteria in the water samples were cultivated using the plate count agar. The isolation of total coliform and Escherichia coli were carried out on Harlequin™ E. coli/coliform agar (HA) medium, while media-faecal coliform was used for faecal coliform employing the membrane filtration technique. Physicochemical parameters such as alkalinity, pH, total alkalinity, total dissolved solid, total suspended solid, electrical conductivity, total hardness, fluoride and chloride ion concentrations, were evaluated in accordance with standard procedures. Data were compared statistically using MedCalc statistical software. Considering the heterotrophic bacterial counts, all water samples were unsatisfactory. For the total coliform counts, 50% of samples were satisfactory but suspicious, while remaining 50% were unsatisfactory. Faecal coliforms results showed that 50% of samples gave excellent quality, 25% showed satisfactory but suspicious quality, while 25% showed unsatisfactory result. There were no significant differences in the total viable, total coliform and E. coli counts of water sampled from universities A and D (p>0.05). The predominant bacterial species was Pseudomonas aeruginosa (23.17%), while the least encountered was Salmonella typhimurium (2.44%). All physicochemical parameters tested were within the acceptable limit.@#This study revealed that the water used by students of studied universities was contaminated with potential bacterial pathogens. However, all physicochemical parameters tested were within the permissible standard limits and satisfied the requirements for domestic utility.
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Qualidade da ÁguaRESUMO
O impacto na qualidade da água causado por reservatórios é usualmente negativo. Essa deterioração se deve, na maioria dos casos, a uma mistura de baixa qualidade, sendo esta fortemente influenciada pelas características de entrada e saída dos reservatórios. Com o intuito de avaliar esse impacto, quatro configurações de reservatório foram testadas (variando a posição da entrada e/ou saída) por meio da ferramenta Computional Fluid Dynamics (CFD). Através dos resultados foi demonstrado, usando como critério a maior concentração média no interior dos reservatórios, que a melhor configuração entre as testadas foi aquela que apresenta a entrada no topo e a saída no fundo.
The impact of water quality caused by storage reservoirs is usually negative. This deterioration of water quality, in most cases, is due to a mixture of low quality water, which is strongly influenced by the inlet and outlet of the reservoirs. In order to evaluate this impact, four reservoir configurations were tested (by varying the position of the inlet and/or outlet) by means of Computational Fluid Dynamics (CFD). The mean concentration inside the reservoirs demonstrated that the best configuration among those tested was the arrangement that presents the input at the top and the output at the bottom.
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Objective To describe the design and production of liquid level system in field. Methods The JYB-714 relay as the liquid level control unit and sensors with special design and installation, supported by pressure pumps, solenoid valves and other components to achieve output driver features. Results The water level automatic control functions are realized smoothly under field conditions without staff on duty in line with local conditions. Conclusion The system works stable with low-cost and the promotion of value of a field hospital can be used as auxiliary equipment, which is portable and easy to integrate.
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To understand the characteristics and causes of the pollution accidents of municipal water distribution network and secondary water supply system.Data on the pollution accidents of municipal water distribution network and secondary water supply system having occurred in recent 20 years were collected and analyzed. The main pollution type of municipal water distribution network and secondary water supply system was biological pollution,the amount of which took 73.3% of the total accidents.The pollution accidents mainly occured in schools or colleges and residential buildings offered by some enterprises to their members and families with an occurrence rate of 11.7%,besides residential quarters,enterprises and institutions.The main links of pollution were observed in municipal water distribution system(51.7%)and water storage tanks high and low lying(43.3%).The main causes of pollution accidents were the leakage and breakage facilities and mislink between the water pipes and sewage pipes, which resulted in formation of negative pressure.Siphonage and sewage flowing backward,in addition the poor sanitary protection facilities polluted by sewage and rubbish. It was the top priorities to establish special legal system,to enhence the preventive sanitary inspection