Volume 31 (2020): Edizione 3 (September 2020)

Most waters in Poland are classified as medium or very hard. In case of industrial waters, their chemical composition and physical parameters play an essential role. The water ought to be soft and should not contain dissolved salts and gases. This water, which has not undergone a softening process, may cause damage to heating devices and boiler scale within a few years. Therefore, water softening is mainly used for heating and energy purposes. However, an important issue is technological processes in which water is used both as a product additive or as an agent in exchange of heat and mass [Reference Document…2001; Nawrocki, Biłozor 2000; Kiedryńska, Papciak, Granops 2006; Biłozor 2012].

The aim of the work was to determine the effect of changes in the proportion of decarbonised water in the process water stream on its parameters (oxidability, general hardness) and parameters of cooling water in water cycles. The possibility of limiting the consumption of raw water to the processes carried out on the premises of the plant and the possibilities of improving energy efficiency in the area of water and wastewater management with a variable stream of decarbonised water in the technological water was checked. It was found that the increase in the share of decarbonised water in the technological and cooling water stream is important in the implementation of process solutions in this area and has a positive effect on reducing costs related to the operational functioning of the water and wastewater management area.

The paper presents results of research on the dynamics of changes in the concentration of polycyclic aromatic hydrocarbons in selected lotic water bodies. Samples were collected in four time frames. The research involved surface water samples collected from three rivers in Poland: the Liwiec, the Muchawka and the Bug. The largest of them is the Bug River, which comprises the Liwiec River. The Liwiec River, in turn, encompasses the Muchawka River. The research was carried out using high-performance liquid chromatography (HPLC). The highest mean total polycyclic aromatic hydrocarbon (PAH) concentration of 184.4 ± 58.3 ng dm⁻³ was obtained in January in water samples collected from the Bug River, while the lowest concentration was recorded in September in water collected from the Muchawka River and was 46.5 ± 18.1 ng dm⁻³. The obtained values do not exceed the permissible limits for surface water used as a source of drinking water for human consumption in accordance with the regulation of the Minister of Maritime Economy and Inland Navigation of 29 August 2019.

History and legal regulations concerning the structure and functioning of the Supervisory Board of the National Fund for Environmental Protection and Water Management are presented in this article. The introduction discusses the historical background of the Fund. Composition and appointment and dismissal of the Supervisory Board members, their rights and responsibilities, as well as the Board's tasks are described in the successive sections. Procedures of the Board's sessions and resolutions and documentation of its activities are presented. The statistics contained in the reports that the Fund's Supervisory Board submits annually to the competent minister are analysed in the final section. The paper concludes with an assessment of legal regulations applying to the Board.

The article presents an assessment of the possibilities of using the heterotrophic denitrification process to remove nitrates from wastewater produced in wet flue gas desulphurisation (FGD) installations and also its optimization in the scope of basic technological parameters. This kind of wastewater is characterized by high salinity (even up to 40,000 g/m³), high temperature (up to 50°C) and low biodegradability, which is expressed by the biochemical oxygen demand (BOD5). The experimental rig consisted of a storage tank and a bioreactor in the form of a bed with an apparatus for measuring basic parameters (temperature, pH, nitrate nitrogen). After an initial adaptation period, a high degree of nitrate nitrogen removal from wastewater (exceeding 95% reduction) was obtained with a reaction time of 180 minutes during the denitrification rate test (NUR). It was also determined that the optimal loading range of the active surface of the bed of 300 m²/m³ should be between 1.5–2.5 gN-NO₃/m²·d. The results of the study show that when the required conditions for the development of microorganisms are provided, it is possible to fully adapt the denitrification biomass to the adverse composition of wastewater from wet FGD unit.