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[en] Assessment of doses due to radionuclides in sewage sludge for different scenarios of its use was made for sewage plant storage in Visaginas, Rimses district, Karlu village. Calculations of individual and collective doses were made on the basis of results of measurements. Two potential exposure pathways from radionuclides in sewage sludge were considered and two scenarios descriptions were made. The first scenario is when the sludge is using for fertilization, and the second one - the sludge is covered with soil. Using program Environ-Calc made by American Chemical Society the number of samples needed to be sampled was optimized. 38 sewage samples were collected for gamma spectrometrical measurements and 10 samples - for measurements of tritium activity. Results of measurements pointed out that the sludge has no higher activity of tritium that background ones. The only two man made radionuclides 60Co and 137Cs were found by gamma spectrometry in the sludge. Average activity for the fresh weight in the samples of 60Co was 42 Bq/kg, 137Cs - 10 Bq/kg. Concentration of natural radionuclides was in the same range as in any soil samples from Lithuania. The dose for the first scenario for 1 years child will be 12 μSv, for adult - 9,4 μSv. In another scenario doses for the workers in sewage plant were estimated as 0,76 mSv. Collective dose in case of use of sewage sludge for fertilizers will be 4,4*10-3 man Sv. The lowest doses will be when the sewage storage is covered using soil. (author)
[en] A good place for the first sludge irradiator in Mexico would be the Toluca Norte sewage water treatment plant. This plant has a definitive biological treatment, and handles only domestic wastewater and assures therefore good and stead sewage sludge quality, and has capacity do deliver sufficient sludge (approximately 22,000 ton.y-1 or 70 ton.d-1) to the irradiator. Capital and operating cost calculations for a sewage sludge plant by irradiation in Mexico were done using a mathematical model considering a 50 k W electron linear accelerator of 10 MeV beam energy, an irradiation dose of 5 kGy, a treatment capacity of 346 ton.d-1, an absorption efficiency of 40%, an electricity consumption of 400 k W, an operating mode of 325 days per year and one shift per day. Total annual operating costs is estimated to be $1,007,900 for treating 346 ton.d-1 with irradiation dose of 5 kGy, including both fixed ($664,000) and variable costs ($343,920). The unit cost at maximum utilization was obtained as $9.00 per ton. (author). 16 refs., 3 tabs
[en] This paper presents some results obtained by using electron beam accelerator applied to sewage and sludge as a disinfectant technology. the samples were collected at two different wastewater treatment stations from Sao Paulo. The disinfection efficiency was observed by the enumeration of total and fecal coliforms and total aerobic bacteria, which were selected for this study once they are universal indicators for biological contamination of water. Doses to be applied were selected in the range of 3.0 to 4.0 kGy for sewage, and 5.0 to 15.0 kGy for sludge. The irradiation induced other benefits than disinfection. The chemical and biochemical removal demand was slightly reduced as well as the total solids residues. (author). 4 refs., 4 figs., 1 tab
[en] This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and coal. The objective is to determine the relationship between (1) fraction sludge in the sludge/coal mixture, and (2) combustion conditions on (a) NO(sub x) concentrations in the exhaust, (b) the size segregated fine and ultra-fine particle composition in the exhaust, and (c) the partitioning of toxic metals between vapor and condenses phases, within the process. To this end work is progress using an existing 17kW downflow laboratory combustor, available with coal and sludge feed capabilities. The proposed study will be conducted in concert with an existing ongoing research on toxic metal partitioning mechanisms for very well characterized pulverized coals alone. Both high NO(sub x) and low NO(sub x) combustion conditions will be investigated (unstaged and staged combustion). The proposed work uses existing analytical and experimental facilities and draws on 20 years of research on NO(sub x) and fine particles that has been funded by DOE in this laboratory. Four barrels of dried sewage sludge are currently in the laboratory. Insofar as possible pertinent mechanisms will be elucidated. Tradeoffs between CO(sub 2) control, NO(sub x) control, and inorganic fine particle and toxic metal emissions will be determined. For the Fifth Quarter of this project we focus on determining whether certain trace metals are associated with certain major species, such as calcium and iron. To this end we present data showing correlations between As, Se,and Sb and major species, such as Ca and Fe. Conversely, lack of correlation between trace metals and elements, such as aluminum can also be used to infer lack of chemical association
[en] Water samples of sewage effluents were collected from sewage collection points located at Latifabad units 9-11, Husainabad and Qasimabad sewage pumping stations. The sewage is pumped towards Southern Sewage treatment plant (SSTP) or is used for agricultural purposes. The water samples from SSTP were also collected and analyzed for pH, conducively, salinity, alkalinity, chlorides, hardness, total, volatile and fixed residues, dissolved oxygen, chemical oxygen demand, nitrogen and phosphorous contents. Variation in the results between sewage water and effluents were noted. (author)
[en] The article from a department for public relations work of the research center in Juelich discusses possible connections between pultonium measurements in the main drainage works of the Nuclear Research Plant and attacks of leukaemia in the neighbouring area of Niederzier. It excludes a connection. (vhe)
[de]Der Artikel aus der Oeffentlichkeitsarbeitsabteilung des Forschungszentrums Juelich diskutiert die moeglichen Zusammenhaenge zwischen Plutoniummessungen im Hauptwaesserungskanal der KFA und Leukaemiefaellen im benachbarten Niederzier. Er schliesst einen Zusammenhang aus. (vhe)
[en] The PIBA (BArros Irradiation Plant), a sewage irradiation plant has being built at Tucuman (Argentina) the National Commission of Atomic Energy. It is designed for insure an absorbed dose of 2 kGy (3 kGy without oxygenation) to 140 m3/day of sludge by gamma irradiation from 60 Co sources. To guarantee that almost all the volume of the irradiate sludge had absorbed at least the fixed dose is more important that its volume uniformity since the desired effect of the treatment is to produce a harmless sewage in respect to the risk diseases. The objective of this work is the calculation if the absorbed dose related to the irradiation time, the operation time and the sources geometry and activity. Mathematical models are developed for obtaining the volume distribution of the absorbed dose. An absorbed dose ≥ 2 kGy is required for the 99.8% of the irradiated sludge volume. Achieving the threshold dose depends upon the total activity which determines the daily time of operation. A numerical set of the major interrelated parameters is given for the efficient operation of the PIBA. (author). 5 refs., 3 figs., 1 tab
[en] Irradiation of sewage sludge is a very important process to eliminate all types of microorganisms and to improve its characteristics, after the irradiation process sewage sludge will have a very good ecological, economic and agricultural value where it can be used safely as a fertilizer because of its nutrient value. Sewage samples were brought from Alhadba Alkhadra wastewater treatment plant in Tripoli and the following microorganisms were isolated: E.coli, Klebsiella, Campylobacter jejune, Bacillus sp., Yeast, Fungi. Samples were then divided into seven groups and received different doses ranged between 0.5 and 3 kGy with an increment of 0.5, one sample was kept as a control sample. The effect of the ionizing radiation was noticed as yeast and fungi disappeared after receiving a dose of 0.5 kGy where as E.Coli and Campylobacter jejune needed a dose of 1 kGy to be eliminated from sludge, a dose of 1.5 kGy was enough for Klebsiella pneumonia, Finally a dose of 3 kGy was needed to clear off the Bacillus sp. bacteria. Ph and E.C. were recorded before and after the irradiation process with no changes.
[en] Field experiment was conducted to study the impact of irradiated and non-irradiated sewage sludge applied to sandy soil on fennel plants (Foeniculum vulgare L.) productivity. In this regards, four rates of sewage sludge application were used (20, 40, 60 and 80 ton/ha) in addition to the mineral fertilizer treatment (control). Sandy soil amended with sewage sludge showed a promising effect on fennel seed yield. A linear gradual increase in seeds yield was observed as the sludge application rate increases. Seeds production increased by 41% to 308% over the control at 80t/ha application rate, for non-irradiated and irradiated sewage sludge treatments, respectively. Irradiated sewage sludge treatments showed higher fennel seed yield than non-irradiated sewage sludge treatments.Volatile oil percent exhibited no observable variation due to the use of sewage sludge. A few and limited fluctuations could be observed. However, total oil content (cc/plot) increased due to the increase in seeds yield. The magnitude of increase in volatile oil production in response to the sewage sludge application was parallel to the increase in seeds yield. The GLC measurements of the fennel volatile oil reveal that, the t-anethole is the predominant fraction. However, fenchone was detected in relatively moderate concentration. The applied sewage sludge treatment induced some variations in fennel volatile oil constituents. The t.anethole is relatively higher in volatile oil obtained from plants grown on sandy soil fertilized with non-irradiated sewage sludge than the one fertilized with irradiated sewage sludge or chemical fertilizer. In the meantime, the obtained increase in t.anethole was accompanied by a decline in fenchone content. Seeds heavy metals (Zn, Fe, Pb, Cd) were determined. Under all sludge application rates iron and zinc concentrations were in the normal plant concentration range whereas, Cd concentrations were traces.
[en] The aim of this work was to assess the differences among soil available P, the use by the plants of sludge P, and of a water soluble fertilizer (Ca(H2PO4)2 ) P, using isotopic exchange kinetics methods. The sludge was provided by the Sewage Sludge Treatment Plant of Tucuman City, Argentina. The isotopic exchange kinetics experiment, in which the fate of carrier free 32PO4 added to the soil solution at a steady state was studied, gives information on soil P exchangeability. The experiment was carried out in the laboratory, where sewage sludge and water soluble fertilizer were added to soil samples taken at a depth of 0-25 and 25-40 cm. Changes in the soil P isotopically exchangeable within 1 minute measurements in the soil with sludge and in the soil with water soluble fertilizer showed that the 0-25 cm deep soil samples had a low P sorption capacity (r1 /R values were low). The sludge had high total and organic P, but the P in the soil solution was lower than the P provided by the water soluble fertilizer. Therefore, despite its higher total P content, this sludge contained slow available forms of P