No abstract

2/g. It exhibits amphoteric properties, and the parameter indicating the nature of the pH, namely a pH of zero charge, is 8.2. In the medium having a pH of less than 8.2 adsorbent material exhibits anion exchange properties, and at pH above 8.2 -cation exchange. For example, the mechanism of removal of arsenate ions from aqueous solutions of this adsorbent is close to the mechanism of removing arsenates in the slightly alkaline anion exchangers [Hering et al. 2004;Bratek et al. 2012]. Research Article ABSTRACT One of inorganic sorbents used in water treatment technology is activated alumina. It is recommended by the European Commission to remove inorganic impurities, such as arsenic, fluoride, selenium and silicates. The adsorbent is usually applied in a granular form, under flow conditions. It can become absorbent material, increasingly used due to the presence of arsenic beside iron and manganese in groundwater intakes. The aim of the study was to evaluate the effectiveness of groundwater treatment in the technological system containing adsorption on activated alumina. The experiment was performed on test model CE 581 manufactured by G.U.N.T. Hamburg, in which four treatment stages can be extracted. The first stage is used in a gravel filter of grain size 1-2 mm, in the second sand filter of grain size 0.4-0.8 mm. The third and fourth phase includes two adsorbers. The first adsorber comprises activated alumina (Al 2 O 3 ) and the other comprises a granular activated carbon. The study was conducted at different speeds of filtration: 5, 10 and 15 m/h. In the raw water samples and the purified water samples after each treatment step the following parameters were determined: pH, O 2 concentration, electrolytic conductivity, SO 4 2-, concentration, NO 3 -concentration, PO 4 3-concentration, Cl -concentration, color, turbidity, iron and manganese concentration, COD Mn , total hardness, calcium hardness, magnesium hardness, content of dissolved substances. The conducted research indicates that optimum filtration rate for most pollution is 15 m/h. Moreover, the presence of activated alumina has contributed to increasing the efficiency of nitrate (V) and phosphate (V) ions removal. STUDIES ON THE EFFICIENCY OF GRUNDWATER TREATMENT PROCESS

Biological membrane reactors or membrane bioreactors (MBRs) based on pressure separation techniques are placed among the latest and most modern methods of wastewater treatment. Currently, this method is becoming more and more popular and is being implemented in smaller and larger wastewater treatment plants (WWTPs). However, technologists, operators, and managers of small WWTPs often do not understand the MBR technology installed in their sites and need extensive professional and technological information. The aim of this study was to analyze the modernized WWTP in a small town of Wydminy, located in northeastern Poland in the Great Masurian Lakes region, where the traditional secondary settling tank was replaced by an MBR. The effectiveness of wastewater treatment before modernization and after installation of the membrane module was compared. On the basis of the conducted research, it was noted that the operation of the plant after modernization is more cost-intensive. There were additional electricity costs due to ensuring adequate pressure on the membrane. Nevertheless, the obtained results of the removal of contaminants place the plant in Wydminy in the group of the most effective Polish sewage treatment plants, as compared to the results obtained in other facilities. The MBR operation also places high demands on the exploiters, prompting them to observe even the smallest changes. The conducted research is a type of a case study, which could give the readers an understanding of the necessity of traditional WWTP modernization with MBR.

The emission of carbon compounds (in the form of soot) to the atmosphere has a significant impact on the environment and human health. Air pollution with combustion products, having a unique combination of physical and chemical properties, is an important component of very fine suspended dust, which is emitted from various sources related to combustion processes. The carbon compounds in aerosol form and deposited in the substrate are found all over the Earth. The paper presents results of comparative research on the content of 16 polycyclic aromatic hydrocarbons (PAH) in soot samples obtained as a result of combustion of solid fuels such as hard coal with granulation above 60 mm, coal with a grain size of 25–80 mm, coal with a grain size of 8–25 mm, pellets and dry wood. On the basis of the conducted tests, it was found that the soot obtained in the combustion of coal in different granulation contains more cytotoxic PAH in comparison to the combustion of wood pellets or dry firewood.

The amount of water required to support a river ecosystem in proper condition are of particular importance in the areas of high natural value. The hydrological threats for the protected areas are region-specific and vary from region to region. The local hydrological conditions depend largely on the temporal and spatial variations of the hydrologic cycle, of the main components and physiographic conditions on site. Future climate change is projected to have a significant impact on the hydrological regime, water resources and their quality in many parts of the world. The water-dependent ecosystems are exposed to the risk of climate change through altered precipitation and evaporation. Investigating the current climate changes and their hydrological consequences are very important for hydrological issues. This analysis may be a very important foundation for determining the causes observed in the recent period of anomalous growth-both hydrological and climatic. The aim of the research is to assess the effect of projected climate change on water resources in lowland catchment the Narew River in Poland. The hydrological reaction to climate warming and wetter conditions includes changes in flow and water level. This paper describes the directions of changes climatic and hydrological conditions and the impact of climate change on the Narew River. The data such as: daily air temperature, precipitation obtained from the Bialystok climate station located within the Narew river and hydrological data such as water flows and water states observed in water gauges were used for the analysis of climate variability and their hydrological consequences. The results show a significant decrease in winter outflows in river, as well as a delayed increase in the spring melt flow. It has also been observed that this is the initial phase of changes in maximum water levels and maximum flows.

No abstract

The aim of this study was to determinate seasonal changes in industrial wastewater treatment effectiveness. Studies were carried out in mechanical-biological wastewater treatment plant in Bystre near Giżycko to which inflows mixture of domestic and dairy wastewater. Laboratory studies were carried out by Water and Wastewater Company in Giżycko. For statistical analysis results form years 2014 and 2015 were considered. The scope of statistical analysis includes basic statistical measures including arithmetic mean, median, minimum, maximum and standard deviation. Changes in seasonal treatment effectiveness were shown by Fisher-Snedecore LSD test. Seasonal changes were observed for BOD, COD and total nitrogen removal effectiveness. Total phosphorus was not subjected to that kind of changes.

One of the most important technological processes of water treatment is the process of filtration. Scientists and producers keep on searching new filtration materials which allow for better water purification, are simple in exploitation and do not add chemical substances to the treated water. Therefore, the aim of the present study was to analyze physical and chemical parameters of two unknown porous masses X1 and X2. Such physical parameters as color, granulation, bulk density, the equivalent diameter, the coefficient of uniformity and the porosity of the material were measured and determined. Additionally, the possibility of water treatment was studied during the filtration process in the laboratory tests. Chemical parameters were examined in the water flowing through the mass, such as pH, conductivity and COD-Mn as a general indicator of the content of organic substances in the water. Both studied porous masses were characterized by uniform size of particles. But they were not efficient enough in satisfactory reduction of oxygen consumption. Mass X2 slightly better adsorbed organic substances. It was found that the tested unknown mass filter slightly increase the pH of the filtered water.