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Phytoremediation of aromatic pollutants and selection of elite clones
1997
Shetty, K. | Nadiga, M. | Zheng, Z. | Lanza, G.R. (University of Massachusetts Amherst, Massachusetts (USA). Lab. of Food and Environmental Biotechnology)
Technology options involving the use of natural and accelerated bioremediation systems to treat complex mixtures of aromatic wastes would be a useful addition to current remediation strategies. The approach outlined in this paper would focus on harnessing the potential of a key detoxification enzyme, glutathione-S-transferase (GST) as part of an accelerated phytoremediation system to detoxify aromatic pollutants in soil and ground water. Major efforts will include the clarification of GST detoxification activity by characterizing the enzyme in a series of phenolic and azo-dye-tolerant phytoremediation candidates (e.g. elite clones of thyme), and the development of methods to manipulate the GST detoxification pathway in elite plant clones to accelerate the detoxification of aromatic pollutants. The information provided by the GST characterization studies could be used to develop significant new phytoremediation systems based on manipulated GST biotransformation pathways in elite plant clonal systems tolerant to highly polluted environments. One major advantage of the new phytoremediation systems would be their potential to perform in highly contaminated environments by providing a favorable rhizophere zone for microbial degradation of aromatics along with an enhanced GST-linked detoxification pathway
Mostrar más [+] Menos [-]Role of EM (effective microorganisms) in sustainable growth
1997
Ono, H. (Larutan Resources Development Corp., Makati City (Philippines))
Isolation, identification and bioremediation potential of oil-degrading bacteria from Manila Bay and Pasig River [Philippines]
1997
Dela Cruz, J. | Halos, P.M.
Oil-degrading bacteria were isolated from waters and sediments of the Manila Bay and Pasig River [Philippines]. Five types of bacteria were isolated from Manila Bay and four from Pasig River. The identified crude oil degrading species are Vibrio sp., Alcaligenes sp., Flavobacterium indologenes and Acinetobacter sp. from Manila Bay, and Pseudomonas aeruginosa, Bacillus sp., Micrococcus sp. and Pseudomonas putida from Pasig River. These isolates were identified through morphological and physiological characterization. The bioremediation potential for each of the isolates was assessed. The percentages oil conversion for the bacterial isolates ranged from 2.99 percent - 53.44 percent in one week's time. Alcaligenes sp. exhibited the highest biodegradation potential for all isolates. Statistical analysis revealed that the mean percentages diesel oil conversion by the isolates were significantly higher than their mean percentages crude oil conversion. Pure and mixed cultures did not give significant differences in their mean percentages crude oil conversion
Mostrar más [+] Menos [-]Role of on-site wastewater treatment system in improvement of water environment in the Philippines
1997
Rondo, M.
Rapid urbanization of the Philippines, especially of Metro Manila area, has caused serious water pollution. Main causes of this are categorized into industrial wastewater and domestic wastewater, discharged without sufficient treatment. As for industrial wastewater, it is essential to put strict regulations on effluent standards, and for municipalities to keep a regular check to ensure these regulations are observed. Philippine government has been working on the improvement of the legislation and control of industrial wastewater until now. However, from now on, it is vital to put more efforts in getting domestic wastewater treated properly. It is indeed crucial to put the existing sewerage construction plans into practice, but generally, sewerage systems require; 1) long construction period, 2) effective funding, 3) high-density construction, and 4) human resources to run the systems effectively. Meanwhile, on-site waste water treatment tanks, or what we called purifiers, can play an important role in controlling the pollution of water environment, and they will serve to complement the sewerage system even after the completion of construction. Small-scale on-site wastewater treatment tanks, or small-scale purifiers, developed and used in Japan especially in developing countries, not only in the scope of environmental conservation but also from the viewpoint of utilizing the economic resources in the private sector
Mostrar más [+] Menos [-]Investigations on the adsorption and degradation of different polar organic compounds in test filter systems
1997
Knepper, T.P. | Wilken, R.D. (ESWE-Inst. for Water Research and Water Technology, Sohnlenstrasse 158, C5201 Wiesbaden (Germany))
Test filter systems are quite helpful to study the persistence of organic compounds in order to give hints for a better remediation of the environment. Therefore special test filters are used in the chemical industry in Germany for more than 20 years in order to determine the microbial bad degradable parts of the dissolved organic carbon (DOC) in the sewage outlets. These test filters can be considered as biological active fixed bed reactors which enable to simulate the biological degradation of organic compounds during an underground passage. It was shown by different investigations, that these test filter systems are well suitable for their expected tasks by determining group parameters. While looking for single compounds they were proven to be such good model systems. For good degradable compounds as e.g., 6-(methyl (phenylsulfonyl) amino)-hexanoic acid (HPS) it could be shown that these substances are microbially degraded on the test filter systems, while the more stable compounds, and an important example for that in Germany is naphthalene-1,5-disulfonic acid, showed a total different behavior. Therefore, the elimination of e.g. napthalene-1,5-disulfonic acid was investigated utilizing labscale filters containing Siran (porous, sintered glass) and activated carbon as support materials for bacteria. However, the different adsorption capacities of activated carbon and Siran had large effects on the measured substrate concentration. Thereby the test filter being run with Siran glass showed to be suitable for modeling the degradation behavior of single compounds during the underground passage. It can be concluded that those test filters can be utilized for studying organic compounds on their behavior as being relevant for water works by means of bad microbial biodegradability
Mostrar más [+] Menos [-]Some chemical aspects of melanoidin decolorization by Bacillus subtilis
1997
Rico, L.B. | Bugante, E.C. | Del Rosario, E.J. (Philippines Univ. Los Banos, College, Laguna (Philippines). Inst. of Chemistry)
The natural melanoidin from alcohol distillery biogester effluent and synthetic melanoidin, which was prepared in the laboratory from equimolar amounts of glucose and glycine were decolorized by Bacillus subtilis in shake flash culture. After eight days of fermentation at an initial bacterial level of 2.9 x 10 E 9 cfu/mL, natural melanoidin was 61.1 percent decolorized as measured by absorbance readings at 475 nm: the corresponding decolorization of 0.041 M synthetic melanoidin was 71.9 percent. Gel chromatography through Sephadex G-100 of natural melanoidin before and after microbial action showed molecular weight (MW) values of 35.6 and 33.5 kD, respectively; the corresponding MW values of freshly prepared and decolorized synthetic melanoidin were 42.6 and 37.7 kD, respectively. Values of the instrinsic viscosity, which is proportional to MW, of natural melanoidin before and after decolorization were 18.46 and 16.96 mL/g, respectively; corresponding viscosity values for synthetic melanoidin were 19.77 and 17.16 mL/g, respectively. After bacterial action both natural and synthetic melanoidins showed greater absorbance at 220-350 nm and lower absorbance at greater than 370 nm but showed reduced infrared intensities corresponding to C=O, C=C and O-H stretching vibrations; however the C-O infrared intensity increased. The results suggest partial depolymerization and oxidative degradation of both melanoidins caused by the microorganisms
Mostrar más [+] Menos [-]Development of bioreactors for denitrification with immobilized cells
1997
Matsumura, M. | Tsubota, H. | Ito, O. | Wang, P.C. | Yasuda, K. (University of Tsukuba, Tsukuba, Ibaraki (Japan). Inst. of Applied Biochemistry)
Macro-porous cellulose carrier (AQUACEL) was applied for immobilization of denitrifying bacteria to develop a practical nitrogen removal system with high performance. When the immobilized cell was applied to denitrification under high nitrogen loading rate, flotation of carriers caused by the evolution of nitrogen gas resulted. To counter the problem of carrier flotation, new reactors using hydrodynamic jet flow and centrifugal force were developed. These new reactors distributed homogeneously the floating carriers, and complete denitrification was obtained even at high loading rate of 20 kg N/cu m-carrier/d. This AQUACEL system was effectively applied to denitrification of wastewater discharged from an eletroplating factory
Mostrar más [+] Menos [-]Major pathways for nitrogen removal in waste water stabilization ponds Texto completo
1997
Lai, Patrick C. C. | Lam, Paul K. S.
A study on the factors influencing nitrogen removal in waste water stabilization ponds was undertaken in an eight-pond series in Werribee, Australia. Nitrogen species including Kjeldahl nitrogen, total ammonia nitrogen, nitrite and nitrate were monitored monthly from March 1993 to January 1994. At the same time, pH, temperature, chlorophylla content and dissolved oxygen were also recorded. Highest nitrogen removal occurred during the period with highest levels of chlorophylla content and dissolved oxygen, but the rate of nitrogen removal was not related to temperature and pH. Enhanced photosynthetic activities resulting from an increased phytoplankton abundance due to prolonged detention time caused an increase in dissolved oxygen, and created an optimum condition for nitrification to occur. In this process, ammonia was oxidized to nitrite and nitrate which were subsequently reduced to elemental nitrogen. Apart from nitrification-denitrification which was the major nitrogen removal pathway in the study system, algal uptake of ammonium, nitrate and nitrite as nutrient sources also contributed to the nitrogen removal. The role of phytoplankton and zooplankton in the treatment process in waste stabilization ponds was discussed.
Mostrar más [+] Menos [-]Effect of copper smelting air pollution on the mites (Acari) associated with young Scots pine forests polluted by a copper smelting works at Giogów,Poland. I. Arboreal mites Texto completo
1997
Seniczak, Stanisław | Dąbrowski, Janusz | DŁUGOSZ, JACEK
The arboreal mites and epiphytes in young Scots pine forests (plant association Leucobryo-Pinetum) polluted by a copper smelting works at Głogów, were investigated. The concentration of heavy metals in Scots pine bark and epiphytes increased towards the pollution source. Copper was accumulated mainly by algae, but lead was accumulated mainly by lichens; these epiphytes accumulated more heavy metals than tree bark. A high concentration of heavy metals was harmful to mites, especially to Oribatida, and to lichens, but algae tolerated these pollutants. The number of oribatid species decreased towards the pollution source, along with the increasing concentrations of heavy metals in tree bark and epiphytes. Among mites, the following categories were distinguished: a) sensitive to heavy metals, b) sensitive to a high concentration but tolerant of small concentrations and c) tolerant of these metals. The mites inhabited mainly the lower section of trees.
Mostrar más [+] Menos [-]A study of atmospheric transparency over qena/upper egypt Texto completo
1997
EL-SHAZLY, S. M.
Atmospheric transparency over Qena/Egypt has been studied for direct solar radiation values, which were calculated from global and diffuse solar radiation measurements. The monthly mean of the instantaneously transparency coefficient has been analyzed in clear-, cloudy-, and mixed days. In general, the value of the transparency coefficient was found to decrease towards the sunset hours, owing to the high aerosol content expected in the afternoon time. The clouds deplete significantly the solar energy passed through them and then lead to an obvious decreasing in the transparency coefficient. A try to calculate the transparency coefficient has been done with the aid of the more available global solar radiation measurements. The results are in a good agreement with those obtained for direct solar radiation. The relation between the daily average of the transparency coefficient and the corresponding mean diffuse fraction has been investigated. High correlations were found between them in all months and empirical formulae were obtained.
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