The article presents common used methods for measuring dissolved oxygen concentration at wastewater facilities. The described methods include Winkler titration and instrumental measurements, such as electrochemical sensors and more recent developed optical ones. The principles, analysis procedures as well as advantages and drawbacks of the methods were discussed. Furthermore, the valid ISO and PN-EN standards for dissolved oxygen measurements were shortly presented with emphasis on the recent changes concerning standards for the optical sensor method. As the results of a survey conducted among wastewater treatment plant operators in southern Poland reveal, optical sensors are being currently preferred in on-line applications due to their enhanced properties in comparison to other measurements methods. ...
The paper presents an analysis of a chain index of water supply and wastewater infrastructure development dynamics in Poland in the years 2003-2013. The work aimed at determining the development index rate (relative growth) of water supply and sewage systems in Poland divided into 3 basic territorial units (rural, urban-rural and urban districts). Moreover, the paper describes the dynamics of changes concerning water consumption, share of population using water supplied by water supply systems, percentage of households possessing a bathroom and flush toilet and the share of population using sewage system during the analysed period. Conducted analyses used among others the chain index of dynamics to determine the rate of observed changes. The analysis revealed the greatest rate of changes for the indices characterising sewage system and the share of population using the system and wastewater treatment plants. Despite the fact that rural areas were characterized by definitely the highest values of the rate of changes and chain index of changes dynamics, the differences between rural and urban areas concerning water supply and wastewater infrastructure in Poland are still considerable. ...
In this paper was analyzed selected components of technical infrastructure functioning in rural areas of the Malopolska, Świętokrzyskie and Podkarpackie Voivodships. The level of equipping rural areas with specified infrastructure elements was evaluated in the form of density and availability of infrastructure components. The work has been specified the rate of change in the analyzed indicators. In each of the provinces was separated 4, homogeneous groups of municipalities due to the level of infrastructure and standard of living. The lack of consistency in the level of the dynamics of the development of infrastructure with the dynamics of the percentage of residents using the equipment was noted. A positive phenomenon is that the development of the sewage system in all three voivodships has a higher average rate than the average rate of the development of the water supply system. This is particularly important due to the significant underdevelopment of the sewage system in relation to the water supply system. ...
