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In recent years, it has been recognized that the laser diffraction gives valuable information on particle size distribution for all types of dry inorganic or even organic materials. With use of the laser diffraction and the laser granulometer, this paper presents the changes occurring in the granulometric distribution of algal agglomerates and the changes in values of percentiles 10, 50 and 90%, determined basing on volume distribution. While assessing the granulometric composition, the existence of a proportional relationship between the diameter values corresponding to the percentile of 10, 50 and 90% was observed. What is more, the obtained results give insight into the possibility of application of the general Avrami equation to describe the granulometric composition of the algal suspension through the analogy of crystals formation from saturated solutions. The analysis shows that the model described by the modified Avrami equation adequately matched the regression to the experimental data on the granulometric composition of algal suspensions. The values of the correlation coefficients were close to 1, which proves that the regression model explained nearly all cases by the dependent variable V i = F(d i ).

Green roofs as solutions that can offer varying levels of stormwater management are the topic of current interest. In order to use this form of reconstructing retention capacity, it is important to understand the influence of meteorological conditions on the functioning of living roofs. The study presents the results of research, using of the ANOVA variance analysis method, on retention performance (i.e. volumetric control) and detention (temporal delay run-off) carried out in the years 2009-2014. The results indicate that the green roof can effectively retain rainfall and delay the initiation of run-off from the rainfall events included in the analysis. Understanding the hydrological performance of green roofs in different local meteorological conditions is key to the successful implementation and development of sustainable practices to control run-off in urban areas. GR -2 [%] CR -1 [%] GR -1 [%] GR -2 [%] CR -1 [%] GR -1 [%] GR -2 [%] CR -1 [%] GR -1 [%] IV CR -1 [%] GR -1 [%] GR -2 [%] CR -1 [%] GR -1 [%] GR -2 [%]

This study presents the construction and calibration of a low-cost piezoelectric microprocessor impactometer designed for the field measurements of the rainfall kinetic energy (KE) flux. Its precise calibration was performed in laboratory conditions using waterdrops of different sizes and fall velocities. High-speed photography was applied to measure the velocity of each waterdrop. Although the impactometer constructed for this study is not able to measure the momentum of waterdrops, its accuracy for measuring their KE is excellent. It was found that the processing of the piezoelectric signal might determine which physical quantity is measured by different impactometers. It was also found that the distance between the waterdrop impact position and the impactometer center has a significant effect on the sensor output. A scheme to account for this effect is developed in this study, and the calibration curve for field applications of the impactometer is derived. In addition, an example comparison of the concurrent field measurements of KE flux using the impactometer and rainfall rates using a weighing rain gauge is given.

The effectiveness of disinfection, as well as microbiological composition of water, are assessed by microbiological tests. The analysis usually takes from 24 to 48 hours. During this time the water produced at the water treatment plant has already been fed to the water supply system. In order to reduce the risk of bacteriological contamination, higher concentrations of disinfectants are maintained. Considering the fact that water supply systems use retention tanks with retention times of from 5 to 12 hours, microbiological tests should give the result in shorter time than water retention time in the water tanks. The aim of the study was to determine whether the bacterial community in static liquid medium with the control of absorbance change at 600 nm (OD600) can be applied as a diagnostic method at water treatment plant laboratories. The research on water and wastewater samples has shown that the duration of lag time λ depends on the approximate amount of bacteria and the initial conditions in liquid media at the start of the experiment. It has been shown that the method can be used in the future for rapid monitoring of bacteriological contamination in the water.

The increasingly stringent requirements for wastewater treatment enforce the adoption of technologies that reduce pollution and minimize waste production. By combining the typical activated sludge process with membrane filtration, biological membrane reactors (MBR) offer great technological potential in this respect. The paper presents the principles and effectiveness of using an MBR at the Głogów Małopolski operation. Physicochemical tests of raw and treated wastewater as well as microscopic analyses with the use of the FISH (fluorescence in situ hybridization) method were carried out. Moreover, the level of electric energy consumption during the operation of the wastewater treatment plant and problems related to fouling were also discussed. A wastewater quality analysis confirmed the high efficiency of removing organic impurities (on average 96% in case of BOD5 and 94% in case of COD) and suspension (on average 93%).

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