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Copyright of Archives of Environmental Protection is the property of Polish Academy of Sciences 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 most common technology for the recovery of energy and valuable materials from sewage sludge is anaerobic digestion (AD). Ensuring thermophilic conditions during AD has been proven to cause process intensification and an improvement in its final outcomes. Nonetheless, the search is underway for other methods to bolster the effectiveness of the AD of aerobic granular sludge (AGS), which is characterized by a compact and complex structure. A prospective AGS pre-treatment technology entails the use of solidified carbon dioxide (SCO2). The present study focused on an evaluation of the AGS pre-treatment with SCO2 on the thermophilic AD technological effects. It evaluated the effect of the SCO2 pre-treatment method on changes in the concentrations of organic and biogenic compounds in the dissolved phase and the yield and kinetics of biogas and methane production in periodical reactors, as well as enabled the development of an empirical organizational model of biogas production. SCO2 introduced to AGS caused an increase in the content of COD, N-NH4+, and P-PO43− in the AGS dissolved phase at SCO2/AGS volumetric ratios ranging from 0 to 0.3. A further increase in the SCO2 dose did not cause any statistically significant differences in this respect. The highest biogas and methane yields were obtained at SCO2/AGS of 0.3 and reached 482 ± 21 cm3/gVS and 337 ± 14 cm3/gVS, respectively. The higher SCO2 doses used led to a significant decrease in the pH value of the AGS, which, in turn, contributed to a decreasing CH4 concentration in the biogas. [ABSTRACT FROM AUTHOR]

Copyright of Economics & Environment / Ekonomia i Środowisko is the property of Fundacja Ekonomistow Srodowiska i Zasobow Naturalnych 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.)

Sediments constitute one of the wastes that are generated in sewage treatment plants. The methods of their final management depend on the sewage sludge system management. One of the employed methods is Autothermal Thermophilic Aerobic Digestion (ATAD). The article presents the process of autothermal oxygen digestion of sewage sludge as a method enabling to obtain biomass, which can be used in the natural environment. In addition to the description of the theoretical basis of the discussed process, the quality of the formed sewage sludge is presented. The amount of sludge and the manner of its final utilisation were also analyzed. The results were presented on the basis of waste records kept in each of the analyzed sewage treatment plants. Sludge transfer cards in 2013-2018 were also analyzed in the sewage treatment plants where sludge undergoes the ATAD process. [ABSTRACT FROM AUTHOR]

The sludge management of many wastewater treatment plants in Poland has not been properly solved yet. The exploiters and designers often have to cope with the dilemma of choosing the method of processing and neutralizing sewage sludge. The method discussed in the article is only one of the options that fully fits in the trends of implementing good practices in the management of sewage sludge. It is a technologically and economically effective as well as environmentally friendly process. It contributes significantly to minimizing the amount of sewage sludge and allows the production of organic fertilizer instead of waste. The work discusses the quality of sewage sludge after autothermal thermophilic stabilization (ATAD). The results of investigations pertaining to the reaction of sludge, dry mass, dry organic matter, content of biogenic substances, calcium and magnesium compounds and heavy metals were analyzed. [ABSTRACT FROM AUTHOR]

The article presents the results of the analysis, which was carried out in 2015-2017 on the example of autothermal installation of thermophilic sludge stabilization (ATAD) in a sewage treatment plant in Giżycko. The installation was created in 2003 as the first of its kind and still remains operational. The purpose of the conducted research was to assess the suitability of the analyzed technological parameters as tools that can be used by operators to determine the actual possibilities of changing the operating conditions of the installation or to develop an optimization strategy to reduce the energy demand. The dry mass content and organic dry mass content was used as the assessment indicators. In the analysed period, the sludge from the process contained from 47.47% to 60.80% of organic matter in the dry mass of the sludge. The organic dry matter decrease due to the process was also calculated, and it ranged from 26.4% to 48.7%. The amount of sludge undergoing the process and the amount of electricity consumption were also analysed. On this basis, the energy consumption indicators in the ATAD process were calculated. [ABSTRACT FROM AUTHOR]

This paper presents a study on the evaluation of digested sewage sludge during the process of Autothermal Thermophilic Aerobic Digestion (ATAD), taking place as a three-tank process at a municipal waste water treatment plant in Luban, Poland. ATAD installation was manufactured by FUCHS Enprotec GmbH Mayen-Deutschland. Over the period from June 2006 to February 2010 sewage sludge digested by tha ATAD-Process was examined. The hydrogen ion exponent was measured in every tank. The results obtained indicated changes in the composition of the digesting sludge at successive stages of the process. Over the study period the ATAD-installation was in both a two- and a three-stage process pH of sludge under study during the process of the thermophilic stabilisation changes and its value grows significantly, with the installation working in a two-stage arrangement from 6,63 to 7,99, and when the installation was operated as a three-stage system from 6,60 to 8,14. The results collected were subject to the statistical analysis. The paper presents conclusions drawn from the study and own experience. [ABSTRACT FROM AUTHOR]

Copyright of Environment Protection Engineering is the property of Oficyna Wydawnicza Politechniki Wroclawskiej 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.)

This study aimed to determine the effect of the low-temperature conditioning of excess dairy sewage sludge using solidified carbon dioxide on the efficiency of methane fermentation. An increase in the solidified carbon dioxide to excess dairy sewage sludge volumetric ratio above 0.3 had no significant effect on chemical oxygen demand concentration in the dissolved phase. The highest chemical oxygen demand values, ranging from 490.6 ± 12.9 to 510.5 ± 28.5 mg·dm−3, were determined at solidified carbon dioxide to excess dairy sewage sludge ratio ranging from 0.3 to 0.5. The low-temperature conditioning caused ammonia nitrogen concentration to increase from 155.2 ± 10.2 to 185.9 ± 11.1 mg·dm−3 and orthophosphates concentration to increase from 198.5 ± 23.1 to 300.6 ± 35.9 mg·dm−3 in the dissolved phase. The highest unitary amount of biogas, reaching 630.2 ± 45.5 cm3·g o.d.m.−1, was produced in the variant with the solidified carbon dioxide to excess dairy sewage sludge volumetric ratio of 0.3. Methane content of the biogas produced was at 68.7 ± 1.5%. Increased solidified carbon dioxide dose did not lead to any significant changes in biogas and methane production. The efficiency of biogas production from unconditioned excess dairy sewage sludge was lower by 43.0 ± 3.2%. The analysis demonstrated that the low-temperature conditioning is an energetic viable technology aiding the methane fermentation process. [ABSTRACT FROM AUTHOR]

This manuscript analyzed the process of autothermal thermophilic aerobic digestion (ATAD) used in installations of municipal sewage treatment plants in Poland. Additionally, solutions for sludge management and the parameters of operating installations were presented. Attention was also put to the energy consumption of the process, where the energy consumption for 1 m3 of sludge treated was between 18.4 and 27.79 kWh. The amount of sewage flowing into the analyzed plants was between 1500 and 14,000 m3/d. On the basis of research carried out in the years 2003–2019 in the selected plants, the characteristics of sludge after the ATAD process were presented. The parameters that determine the usefulness of the sludge as an organic fertilizer were indicated above all. The content of total nitrogen, which was from 2.4 to 8.1% of dry matter, ammonium nitrogen, which was from 0.8 to 1.8% of dry matter, and total phosphorus, which was from 1.1 to 4.2% of dry matter, recommended using sludge for fertilization. It was also pointed out that sewage sludge should be regularly tested for the dynamics of changes in chemical composition and biological parameters. These are the factors that increase risk and limit the use of sludge for fertilization. [ABSTRACT FROM AUTHOR]