Water management in cities is a critical factor for sustainable growth and development. Satisfying the current needs with respect for the future is not possible without properly managed water and wastewater systems. An essential element of wastewater systems is the wastewater treatment plant (WWTP). The nexus between wastewater treatments and energy demand is a well-known problem. In times of energy crisis, effective energy management in this critical infrastructure is a key task. The purpose of this article is to analyze WWTPs’ energy consumption with regard to proposed management strategies for managers, designers and decision makers. A detailed analysis of WWTP operational parameters and a proposal of improvement actions will be useful for applicability and benchmarking studies. Estimating the carbon footprint (CF) of selected WWTPs considering the indirect emissions due to energy consumption is an important step for developing energy neutrality of WWTPs. Due to the desire to deepen research in the area of a complex phenomenon, which is the energy management system in WWTPs, the research undertaken herein is based on the case study method of three water and sewage companies operating southwestern Poland. Each urban area has different specificities, natural conditions and needs. The presented results of the analyses may be the basis for developing directions for changes in national policy, other benchmarking studies, and improving the energy management system in WWTPs.

Waste Water Treatment Plant (WWTP) belong to the so-called �critical infrastructure�, which are so essential that their continued operation is required to ensure the security of a people. Energy is the most important operating utilities of WWTP. The specific electric energy consumption of WWTP depending on many factors including the inflow quality, WWTP�s scale, the technology used and climate. High energy consumption indirectly produces ecological damage, accelerates the energy crisis, and increases carbon emissions. The article will present data on analysis electricity consumption and carbon footprint at a small wastewater treatment plant in southern Poland. Electricity consumption of the analyzed wastewater treatment plants in 2019-2021 ranged from 221 714 to 248 824 kWh/year, with an average value of electricity consumption rate per m3 of wastewater: 1.15 kWh/m3. Rising amount of pollutants conducted into the treatment plant results in an increased energy demand. However, this correlation does not take a linear character.

Planowanie i realizacja przedsiwzi budowlanychs procesami trudnymi i obcionymi wieloma elementami ryzyka.Budet rozoony w czasie, ktry opracowuje si na podstawieharmonogramu, przedstawia oczekiwany rozkad kosztw przezcay okres trwania robt, ktry w trakcie realizacji przedsiwziciapodlega ustawicznym zmianom, wynikajcym z czynnikw czasowych,kosztowych i organizacyjnych. Zarzdzanie kontraktamibudowlanymi wymaga od menederw umiejtnoci biecejanalizy odchyle ponoszonych kosztw produkcji od wartociskalkulowanych kosztorysem ofertowym i zaoonych w harmonogramierzeczowo-finansowym.W artykule podjto prb analizypowstajcych odchyle czasowych i kosztowych autorskim monitoringiemC-S i S-C, bazujcym na zoonych wskanikach metodyEVM. W badaniu odchyle kosztw planowanych i kosztw poniesionychprzez wykonawc posuono si przykadem budowyosiedla wielorodzinnej zabudowy mieszkaniowej.Sowa kluczowe: metoda wartoci uzyskanej, odchylenia czasowe,odchylenia kosztowe, harmonogram.

In light of the ever-increasing need for a circular economy in all sectors, the rail ballast reuse during the railway lines reconstruction can be an important element in the implementation of sustainability principle. However, this activity should be carried out in a responsible way based on environmental risk analysis due to the contaminated ballast may pose a hazard, especially to deterioration for the quality of soil and water. This paper presents new method for environmental risk assessment of the impact of rail ballast reused as a construction material. The proposed method was verified on a real site at five selected point on trans-European TEN-T transport network in south Poland. The obtained results confirm the possibility of direct reuse of ballast at 4 of the 5 analyzed points. The case study highlights the technical feasibility and desirability of using recycled ballast in the reconstruction of railway tracks. Moreover, papier presents a new tool to assess when such a process can be carried out safety for an environmental. Additionally based on the results of presented studies may establish an understanding on relevant processes and environmental risk of railway emissions to soil, drainage water and groundwater.

The Planning and implementation of construction projects are difficult processes and are burdened with many risk elements. The budget spread over time, which is developed on the basis of the schedule, presents the expected distribution of costs throughout the duration of the works, which during the implementation of the project is subject to constant changes resulting from time, cost, and organizational factors. Managing construction contracts requires managers to be able to analyze on an ongoing basis the variances of production costs-from the values calculated in the offer cost estimate and assumed in the Budgeted Cost of Work Scheduled. The article attempts to analyze the emerging time and cost deviations using proprietary time variances from the schedule (T/S) and variances from planned costs (T/C) monitoring, based on simple indicators of the earned value method (EVM). An example of construction of a multi-family housing development was used to study the variances of planned and incurred costs.

A prerequisite for achieving high energy efficiency of water supply systems (understood as using less energy to perform the same task) is the appropriate selection of all elements and their rational use. Energy consumption in water supply systems (WSS) is closely connected with water demand. Especially in the case of oversized water supply systems for which consumers’ water demand is at least 50% less than previously planned and flow velocity in some parts of the system is below 0.01 m·s−1, this problem of excessive energy consumption can be observed. In the literature, it is difficult to find descriptions and methods of energy management for such a case. The purpose of this study was both an evaluation of the current demand of an oversized WSS and a preliminary technical analysis of the possibility for energy saving. Solutions are presented that resulted in improvements in energy management, thus increasing energy efficiency. The conducted analyses indicate the wide use of numerical, hydraulic models, among others, for the needs of the sustainable oversize water supply systems management in order to improve energy efficiency. Those simulations only give energy consumption results as a first step in the process of decision-making for the modernization process, in which investment costs should be taken into account as a second step. Thus, this paper emphasizes the crucial role of hydraulic models as a good analytical tool used in decision support systems (DSS), especially for large, oversized water supply systems.

A feasibility study is a measure of the quality and reliability of construction schedules. In the course of construction projects, there are a number of external factors that generate time delays and cost variances. Their detailed monitoring and identification allows managers to implement improvement measures. The purpose of the research is to build a decision model that controls the distribution of the resulting time and cost variances identified on the given day of the work registration report. The works assortment processes burdened with the variances in the preceding activities, foreseen to be performed after the selected inspection day were subjected to the improvement measures. Delayed schedule control using milestones allows for the division of time slips by setting priority working deadlines. These deadlines initially eliminate time reserves, making all activities critical.

Halogen derivatives of hydrocarbons - trihalo-methanes (THMs), are formed in disinfected swimming pool water - mostly when chlorine compounds are used for the process. Meanwhile, chlorination has been widely used for disinfection swimming pools water in many countries to destroy waterborne pathogenic organisms. THMs have a negative impact on human health because they are carcinogenic and mutagenic. Therefore, many countries have established strict regulations to control these disinfection byproducts In Poland, the contents of THMs in swimming pool water and air are standardized, the norm for swimming pool water is 100 g/dm(3). Several factors can influence the THMs formation in water, but most important are processes and chemicals used for water treatment. The literature presents a lot of data on disinfection by-products in pool waters, but so far no research has been done in small home facilities with a simple water treatment and disinfection system. The purpose of the paper was to analyze changes in trihalomethane concentrations during the operation of small swimming pools. During the analysis, the influence of various factors such as the temperature of the atmospheric air, temperature of the water in the swimming pool, chlorine content and the number of bathers on changes in the concentrations of trihalomethane in the water were investigated. The effect of the sand filter on the reduction of trihalomethanes was also investigated. It has been shown that there is no single factor that directly affects the changes in trihalomethane concentration, each factor contributes to the formation of THMs in pool water. It was also noticed that the amount of trihalomethanes contained in a small pool installation significantly exceeds the normative values contained in the regulation

Records of the national, average pay rates in the construction industry, at quarterly intervals, allow cost - planning departments of contractors and investment services to assess current market conditions in the construction industry. Price quarterly publications, such as Sekocenbud and Intercenbud, contain important information, enabling production preparation departments to prepare a comparison of the production in-house labor rates with the market production labor rates. The article attempts to analyze the economic situation of domestic construction production in the years 2010-2016 based on the emerging price trends of the of labor cost estimates in this period, taking into account the impact of seasonal construction services. In "Polish cost estimates standards", the labor cost estimate rate is present in one form: the net labor cost estimate rate, which fully corresponds to the rate defined in calculation formulas. The rates of labor cost estimates, in individual regions of Poland, are shaped according to the presented market situations. This clearly is reflected in the periodic (quarterly) regional records of labor rates in the Sekocenbud system. The Act on prices of July 5, 2001 does not contain any normative regulations regarding the methods of cost estimation of construction works. The necessity to remain competitive forces large construction corporations to use a subcontracting system, involving several or even several dozen smaller, specialized in a narrow range of works, business entities in which labor costs are definitely lower, because they are reduced by a lower value of internal costs.

Czasopismo Techniczne » 2017 » Volume 5 » Analiza czasowo-kosztowa w monitoringu harmonogramu metodÄ wartości uzyskanej A A A

Production downtime results from the technological regime of production processes, established in production diagrams as network nodes. Their direct cause in the lack of harmonization between working teams, diversity of performance of hardware units – working in mixed systems, and different labor construction processes, performed on the same working plots. Time and costs analysis lies in optimizing the downtime of production resources using the “by-pass” production, which allows production labor (R) and hardware measures (S) for the implementation of part of the process. This tool is defined in network nodes, slowing down the production and binding the run of the production front with a two criteria network plan: technologically and organizationally. The technique is based on an algorithm of the limitations of renewable resources of means of production, which assumes the full availability of construction materials, available from storage sites. The paper presents an analysis of fixed and variable investments costs in terms of compensating for downtime.

The subject of the thesis is the main schedule of the investment cycle based on the two-point relation net of CPM. In the thesis, the analysis of technological regime of net buffers has been made with the special attention to the possibility of locating by-passes and defining their significance in order to level the junction buffers. The lengths of the paths before and after defining the by-passes were compared, which give the overall effect of the shortening of the schedule of the investment cycle. The analysis shows that, the investment cycle after location of a on some of the nodes is 20% shorter. The proposed algorithm does not eliminate node buffers of wasted time. It introduces the concept of a by-pass node with regulated flow of production, adjustable with weight of the so that certain operations can be carried out in the course of activities aiming at the analyzed node. After leaving the works of this node, the time of subsequent activities is shorter, and therefore cheaper for operations already carried out with by-pass. The presented technique of shortens the overall production time, lowering the fixed costs and leaving the changeable costs at the same level, because it does not lower or increase the resources of any means of production.

The article focuses on both results of analysing the quality of the surface water taken from the reservoir and effectiveness of the water treatment process' technological examinations carried out both on a pilot station and in a technical scale. The research was carried out on the basis of the water taken from the reservoir named "Sosnowka" which is located at the Karkonosze mountain range bottom. There were 27 physical and chemical factors that underwent the examination.The effectiveness of the water treatment process was assessed basing on such factors as follows colour reduction, turbidity and such indicators as: alkalinity, total hardness, oxidability and conductivity.The 1st stage carried out throughout the water year included examining of the water treatment process' effectiveness in a pilot station in various technology systems by means of such unitary process as: sieving, pre-ozonation, pH correction, coagulation, filtration on anthracite and sand bed, final ozonation and sorption on active carbon. The other stage concerned examination carried out in a technology system in a technical scale of a new water treatment plant. The good quality of the examined water at that time (pH = 6,9; colour = 15 mgPt/L-1) allowed for using a simple technology system with the use of such processes as: sieving, pre-ozonation, filtration on anthracite and sand bed, final ozonation and sorption on active carbon and final correction of the water quality with Na2CO3 and MgCl2.The results aquired while carrying out laboratory technological examinations and those in technical scale allowed for establishing 3 optimal technology systems to be implemented while the water treatment plant operates.