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Copyright of Ecological Engineering / Inżynieria Ekologiczna is the property of Polish Society of Ecological Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article presents the results of sulfur and nitrogen conversion to flue gas components during the oxy-combustion of municipal sewage sludge. In Poland, some dynamic changes in the implementation of thermal treatment methods in sewage sludge management have been observed over recent years. A few new installations have been commissioned with a fluidized bed technology under air-firing conditions. Until 30th December 2012, there were in Poland, 11 municipal sewage sludge incineration plants that had jointly a total capacity amounting to 160,000 Mg/y. Since the oxy-combustion technology has been researched widely mainly in coal combustion, the experiments carried out at 0.1 MWthCFB combustor have focused on sewage sludge combustion and sulfur, nitrogen conversion to flue gas components in the conditions of increased oxygen concentration and different process temperatures. The oxygen concentration in a feed gas was increased from 21 to 35% per volume. An increase in sulfur and nitrogen conversion ratios was found under the oxy-combustion conditions. [ABSTRACT FROM PUBLISHER]

The article presents the results of research on the impact of inorganic coagulants and polyelectrolytes and their common action on non-prepared and sonicated digested sludge. Sonication of sludge samples was carried out under static conditions for 60, 120, and 180 s. An ultrasonic wave off = 20 kHz and two different amplitudes ofA = 15.25 and 30.5 μm were used in tests. The coagulant PIX123 and the polyelectrolyte Zetag 8160 were used for conditioning. On the basis of CST test, doses of chemical reagents were chosen for conditioning. The results indicated the effect of the PIX123 and Zetag 8160 application on non-sonicated and sonicated sludge. The lowest CST values were achieved, while the combination of coagulant in a fixed dose of 1.0 mg/g and polyelectrolyte was used. This effect was observed for non-sonicated sludge as well as for sonicated sludge. The higher dose of chemical reagent used for non-sonicated sludge, the lower the final hydration was achieved. For non-sonicated sludge, better results were obtained when the Zetag 8160 was used. For sonicated sludge, better results were achieved when PIX123 was used. The effect of the final hydration reduction for sonicated sludge and prepared with Zetag 8160 was not satisfactory. The application of the coagulant and the polyelectrolyte combination does not allow achieving lower final hydration of sludge in comparison with only PIX 123. However, it was possible to achieve higher suspension and COD reduction. [ABSTRACT FROM PUBLISHER]