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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
Show more [+] Less [-]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
Show more [+] Less [-]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
Show more [+] Less [-]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
Show more [+] Less [-]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
Show more [+] Less [-]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
Show more [+] Less [-]Partitioning of heavy metals in podzol soils contaminated by mine drainage waters, dalarna, sweden
1997
HERBERT, R. B., JR.
The discharge of acidic mine drainage waters onto a hillslope in Dalarna, central Sweden, has lead to the contamination of the podzol soils with Cu, Fe, Ni, Pb, Zn and sulfate. Samples from contaminated and reference soils have been collected for chemical and mineralogical analyses. Jarosite is identified by x-ray diffraction analysis as a precipitate in the upper horizons (A, E, B) of the contaminated soils, where the soil acidity (pHKCₗ ∼ 2.6) promotes jarosite stability. The sequential chemical extraction of soil samples indicates that, in the reference A horizon, Cu, Pb, Ni and Zn are bound primarily to cation exchange sites and organic matter. In the A horizon of the contaminated soils closest to the rock dump, metal partitioning is dominated by the Fe oxide fractions, despite the high organic matter content; Pb is almost completely bound to crystalline Fe oxides, possibly adsorbed to Fe oxides or occuring in a jarosite solid solution. In the reference B and C horizons, Cu, Ni and Zn are primarily adsorbed/coprecipitated in the Fe oxide fractions, while Pb remains with a large fraction bound to organic matter. In the Fe-rich B horizon of the contaminated soils, the partitioning of the metals in cation exchange sites and to organic matter has greatly increased relative to the reference soils, resulting from the mobilization of organo-metal complexes down the profile.
Show more [+] Less [-]Weathering processes under various moisture conditions in a lignite mine spoil from as pontes (N.W. Spain)
1997
Seoane, S. | Leiros, M. C.
Processes contributing to acid release/consumption during weathering of a lignite mine spoil (2.3% w/w S as sulfides) from As Pontes (N.W. Spain) were studied under three moisture conditions (at field capacity or under alternate wetting-drying or forced percolation), which were simulated in laboratory experiments. Oxidation of sulfides to sulfates was favoured under all three moisture conditions, releasing most acid in spoil kept at field capacity. Hydroxysulfates formed in spoil kept at field capacity or under alternate wetting-drying conditions, thereby contributing to acid release. Acid consumption by dissolution of clay minerals, especially micas, was favoured under all three moisture conditions, but was particularly intense in spoil at field capacity. Dissolution of aluminium oxides was also favoured under all the moisture conditions studied.
Show more [+] Less [-]Pigment changes in norway spruce induced by dust pollution
1997
MANDRE, MALLE | TUULMETS, LIIVI
The influence of alkaline dust pollution (pH of water solution of dust 12.3–12.7) from a cement plant (Kunda town, Estonia) on chlorophylls and carotenoids of the needles of 60–80 year old Norway spruce was studied on sample plots established at different distances from the emission source. The highest sensitivity to dust impact was measured in the content of Chl a, Chl b, carotenoids and elements regulating or participating in the biosynthesis of pigments (Mg, Fe, N, Mn).
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