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The deficiency of readily biodegradable organic carbon can be a significant limitation to effective nitrogen removal during wastewater denitrification. Waste-activated sludge (WAS) is a source of carbon produced directly at wastewater treatment plants (WWTPs). Raw WAS has a large molecular weight and complex chemical structure molecules that are not easily available for microorganisms. In this study, easily biodegradable organic fractions were released using pH control and/or nitrites and nitric acid (NO2/FNA). The obtained results indicated that WAS can be a sufficient carbon source for denitrification in WWTPs that are at risk of minor effluent violations. The implementation of WAS disintegration with the use of pH control and NO2/FNA allowed for the denitrification of an additional 0.5 and 0.8 mgN-NO3/L. WAS disintegration, besides being a source of carbon generation, reduces the volume of sludge and leads to the implementation of a closed-loop system. [ABSTRACT FROM AUTHOR]

Protozoa grazing of nitrifiers is important process in activated sludge process that leads to decrease of mass of active bacteria. In classical models this process is included in decay processes. Such approach makes modelling of influence of protozoa grazing on nitrifiers impossible. In cases when maximization of nitrifiers growth is important (such as nitrifiers cultivation for bioaugmentation) this simplification becomes major drawback. This paper presents extended version of ASM3 model that includes protozoa grazing as well as results of calibration of protozoa grazing process on experimental data. Additionally new approach for analysis of decay rate is proposed. This approach includes calculation of new parameters: substitute decay rate which is sum of ASM3 base decay rate and excluded predation process.

Sludge drying leads to volatisation and removal of part of nitrogen contained in sludge. Removed nitrogen is usually condensed and recirculated to activated sludge process. It is assumed that mass of volatised nitrogen is equal to mass of soluble nitrogen in sludge. However results obtained from full-scale drying facility shows that mass of volatised nitrogen is 100% higher than mass of soluble nitrogen. It is suspected that nitrogen mineralization occurs due to high temperature maintained in dryers (> 220°C). These results are important as higher mass of nitrogen in condensate makes its removal economically reasonable. This paper shows results of nitrogen mass balance of full-scale drying facility.

Bacteria responsible for ammonia oxidization (AOB) can be differed into two groups which have different bio kinetic parameters. Those groups are slow growing bacteria with lower half saturation coefficient for NH4 (k -strategist) and fast growing bacteria with higher half saturation coefficient for NH4 (r- strategist). By controlling operational conditions of process it is possible to create dominance of one of those colonies to enhance the nitrification rate. Therefore model of sequencing bath reactor was developed to study the correlation of bioaugmentation of the side stream breeder reactor and predominant AOB culture. The course of the study was to find the minimal bioaugmentation influent of AOB rich recycled sludge to create dominance of k-strategist in the side stream reactor with maintaining maximal possible increase of overall AOB load. In addition operating conditions like sludge retention time, NH4 concentration and loading regimes was investigated to determine the optimum for the process.

Aims: Coronary artery perforation is a rare but potentially serious complication of percutaneous coronary intervention (PCI). Clinical manifestation and prognosis of patients depend on the severity of the complication, the occurrence of tamponade, and the methods of treatment. A special type of perforation is caused by damage to the distal segment of the coronary vessel by guidewire. This type of perforation is mostly connected with subacute clinical presentation. The treatment can be difficult, especially when prolonged balloon inflation is not efficient. The aim of the article is to present a balloon fragment technique as a treatment method for distal vessel perforation., Methods: The method of treating distal perforation, which we presented at EuroPCR 2019, involves embolization of a perforated vessel with a cut part of balloon catheter. Six patients are included in this registry; only 1 truncated proximal balloon fragment was enough to effectively embolize the perforated vessel in 4 patients, while 2 balloons were required in 1 patient and 3 balloons were required in 1 patient., Conclusion: Compared with other methods, this technique is an easy, cheap, and effective treatment for distal vessel perforation. The described method is available in every catheterization laboratory and does not require expensive equipment or exceptional operator experience.