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Assessing the Feasibility of Recovering Water from Treated Municipal Wastewater

Dąbrowski Wojciech, Bagińska Sylwia, Malinowski Paweł

Journal of Ecological Engineering

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2024

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Vol. 25, nr 1

119--130

EN

The problem of recovering water from treated wastewater may concern an increasing number of countries, especially those with low water resources. After costly treatment processes, water taken from surface and underground intakes is used and then largely discharged to receivers in the form of treated wastewater. Advanced wastewater treatment methods ensure that the treated wastewater is characterized by very low physical and chemical pollution, sometimes better than the water quality in the receiving basin. The research was conducted under a cooperation agreement between Bialystok University of Technology and Bialystok Waterworks Ltd. The recovery of water from wastewater was one of the topics pursued.This paper analyzes the parameters of treated wastewater from the largest municipal wastewater treatment plant in the Podlaskie Province. The analysis of the treated wastewater composition was based on monitoring studies conducted by the company Bialystok Waterworks Ltd. between 2020 and 2023. The analysis concerned the basic parameters of wastewater, namely the content of organic matter and total suspended solids.This was due to the requirements for the recyclability of treated wastewater. Linear modeling was performed to determine if a sufficiently strong correlation was detected;otherwise output distribution characteristics were provided.In all cases, the output concentrations were far below the class A limits for irrigation in the whole research period.

2

Integrated preprocessing techniques with linear stochastic approaches in groundwater level forecasting

Azari Arash, Zeynoddin Mohammad, Ebtehaj Isa, Sattar Ahmed M. A., Gharabaghi Bahram, Bonakdari Hossein

Acta Geophysica

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2021

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Vol. 69, no. 4

1395--1411

EN

Accurate modeling of groundwater level (GWL) is a critical and challenging issue in water resources management. The GWL fuctuations rely on many nonlinear hydrological variables and uncertain factors. Therefore, it is important to use an approach that can reduce the parameters involved in the modeling process and minimize the associated errors. This study presents a novel approach for time series structural analysis, multi-step preprocessing, and GWL modeling. In this study, we identifed the time series deterministic and stochastic terms by employing a one-, two-, and three-step preprocessing techniques (a combination of trend analysis, standardization, spectral analysis, diferencing, and normalization techniques). The application of this approach is tested on the GWL dataset of the Kermanshah plains located in the northwest region of Iran, using monthly observations of 60 piezometric stations from September 1991 to August 2017. By removing the dominant nonstationary factors of the GWL data, a linear model with one autoregressive and one seasonal moving average parameter, detrending, and consecutive non-seasonal and seasonal diferencing were created. The quantitative assessment of this model indicates the high performance in GWL forecasting with the coefcient of determination (R2 ) 0.94, scatter index (SI) 0.0004, mean absolute percentage error (MAPE) 0.0003, root mean squared relative error (RMSRE) 0.0004, and corrected Akaike’s information criterion (AICc) 151. Moreover, the uncertainty and accuracy of the proposed linear-based method are compared with two conventional nonlinear methods, including multilayer perceptron artifcial neural network (MLP-ANN) and adaptive neuro-fuzzy inference systems (ANFIS). The uncertainty of the proposed method in this study was±0.105 compared to±0.114 and±0.126 for the best results of the ANN and the ANFIS models, respectively.

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Wybrane zagadnienia eksploatacji układów wirnik-łożyska.

Kozanecki Z.

Zagadnienia Eksploatacji Maszyn

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2005

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Vol. 40, nr 1

25-36

PL

Rozwój nowych technologii i coraz szersze zastosowanie nowych materiałów w budowie maszyn pozwala na rozważenie koncepcji budowy nietypowych łożysk przeznaczonych dla wirnikowych maszyn przepływowych. W artykule podjęto próbę klasyfikacji łożysk stosowanych w tej grupie maszyn pod kątem różnych kryteriów. Rozważono pewne rodzaje łożysk, które wykorzystują inną zasadę działania niż łożyska stosowane zazwyczaj w tej grupie maszyn. Na potrzeby tej publikacji nazwano je łożyskami "niekonwencjonalnymi". Nowe technologie i nowe rozwiązania dla węzłów łożyskowych zwłaszcza tzw. "aktywne" łożyska charakteryzują się dodatkowymi możliwościami niespotykanymi w klasycznych rozwiązaniach. Na przykład zaawansowane systemy aktywnych łożysk magnetycznych pozwalają na identyfikację zewnętrznych sił oddziałujących na wirujący wał oraz na aktywną kontrolę drgań poprzecznych wału. Zasadniczym problemem związnym ze stosowaniem niekonwencjonalnych łożysk w praktyce inżynierskiej jest zapewnienie ich niezawodnego działania w różnych warunkach funkcjonowania maszyny. Dlatego zastosowania te wymagają przeprowadzenia dokładnej analizy dynamicznej systemu rotor-łożyska-fundament w całym zakresie możliwych parametrów pracy maszyny. W artykule pokazano wybrane przykłady koncepcji i zastosowania takich rozwiązań w maszynach przemysłowych.

EN

A development of new technologies and more and more numerous applications of nonconventional materials to machine design allow one to consider the idea of buiding new types of bearings designed for turbomachines. This paper proposes a classification of turbomachinery bearings with respect to various criteria. There are a few types of bearings, which employ a principle of operation that is not typical for the given application range. For the needs of the present paper, they are defined as "unconventional" bearings. New technologies and search for new solutions of bearing systems allow one to assume that "active" bearings can yield some supplementary capabilities, unparallel in classical solutions. The advanced systems of active magnetic bearings are also used for identification of the external dynamic forces acting on the rotating shaft and, finally, for the shaft vibration control. One of the basic problems connected with a practical application of "unconventional" bearings is the machine operational reliability under various working conditions. Therefore, one should analyse thoroughly the dynamics of the rotor-bearing-casing system in the whole operating range of the machine. Some selected examples of unconventional bearing applications in rotor support systems of rotating industrial machinery are presented.