Maciej Mrowiec

Methods of Flushing of Sewage Sludge Collected on the Bottom of a Retention Chamber of the Sewerage Reservoir

This paper presents new achievements in the field of designing the gravitation and gravitation-underpressure chamber for bottom flushing in the detention chamber immediately after its emptying from the accumulated sewage. Temporary accumulation of the sewage in the detention chamber of the reservoir causes partial sedimentation of the solids suspended in the liquid. The location of the flushing chamber at the maximal level of filling with sewage in the retention chamber substantially improves the effectiveness of flushing of the bottom of the retention chamber with the stream of sewage that is discharged from the flushing chamber. An opportunity for effective flushing of the sludge that remains on the bottom of a detention chamber represents an important operation which is essential for reliable functioning of retention reservoirs within sewerage systems.

Retention capacity of extensive green roofs

Abstract Climate change causes a more frequent occurrence of extreme events. The result of these phenomena is the occurrence of floods and flooding, and periods of drought. Particularly unfavorable is intensive rainfall over the urban catchments. To prevent the negative consequences of these phenomena, unconventional solutions should be used. The use of green roofs in urban areas will serve the sustainable development of cities and the impact on local ecological changes. The study was performed at two green roof platforms 1.2×1.2×0.1 m each. An analysis was performed at different intensities given for precipitation. 20 min for the rain to stop was observed from 68 to 100% precipitation. The study was divided into two parts. The first part of the study has been performed in the dry period. In contrast, another round of tests was repeated in other conditions after rainfall. The amount of water at two experimental green roofs platforms before the test was 11.0 dm3. The research relates to the impact of green roofs on local hydrological changes. Development of technologies for green roofs had a positive impact on mitigating the effects of climate change associated with the occurrence of flooding the city.

Zastosowanie metody wymiarowania niecek infiltracyjno-retencyjnych do zagospodarowania wód opadowych

The easiest way to “use” rainwater is its detention in places where it falls, and referral to the ground. Systems of rainwater utilization system can be implemented in different variants. In the simplest configuration it is a tank, with a runoff from the roof. The principle of operation of the tank (basin) is a method for rain water management. The article presents a practical application of methods of dimensioning infiltration basins by performing calculations showing how to alter the dimensions of the basin when changing the ground conditions while maintaining the same filling.

THE INFLUENCE THE EXTENSIVE GREEN ROOFS ON THE OUTFLOW RAINWATER TO THE SEWAGE SYSTEM

In times of rapid urbanization and climate change has drawn more attention to stormwater runoff to sewer systems. The phenomenon of flooding in urban areas have become increasingly common as a result of heavy rains. Sewage systems in such a short time are not able to accept such a large amount of rainwater flowing on the site, which we experience the phenomenon of rainfall flowing down the street in excessive amounts. The problem of such phenomena can be solved by the development of green roof technology. Even in its simplest form that extensive green roof is able to delay outflow, and store in its entirety falling falls on the area. Everything depends on the layers and the size of the roof. The research study presented at two mini green roof, an area of 1.44 m2. Both cases have different layers. One of them has a layer of non-woven filter layer, the substrate and vegetation. The second station is built of layers of drainage, filter layer, a layer of substrate and vegetation. For experimental purposes a rain shower were used for testing, which allows to calibrate the right amount of water at a specified time. In the research of precipitation 10, 15 and 20-minute tested. On the bench number 1 a reduction in the range of 48.9 to 97.5% was achieved. The second experiment stand showed a higher retention capacity ranged from 74.5 to 94.7%. We concluded that the use of extensive green roofs in cities can help reduce storm water runoff from impervious surfaces.