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  • Terahertz Dual-Band Metamaterial Biosensor for Cervical-Cancer Diagnostics
    • Musa Hamza
    • Mohammad Alibakhshikenari
    • Bal S. Virdee
    • Muhammad Hamad
    • Salahuddin Khan
    • Sławomir Kozieł
    • Ernesto Limiti
    2024 Pełny tekst IEEE Photonics Journal

    This study highlights the potential of employing terahertz metamaterial structures as dual-band biosensors for the early detection of cancerous biological tissue. The fundamental principle leveraged here is the alteration of the effective dielectric constant of biological tissue by cancerous cells. The change in the dielectric constant, in turn, induces a shift in the resonance frequency of the metamaterial sensor. One notable advantage of the terahertz metamaterial sensor is its relatively compact size compared to other sensor types, as its dimensions are independent of the wavelength. This property translates into a requirement for a much smaller biopsy sample, facilitating less invasive testing procedures. Beyond the size advantage, the proposed biosensor demonstrates efficacy in detecting abnormalities within biological tissue.

  • Testing Topological Conjugacy of Time Series
    • Justyna Signerska-Rynkowska
    • Paweł Dłotko
    • Michał Lipiński
    2024 Pełny tekst SIAM JOURNAL ON APPLIED DYNAMICAL SYSTEMS

    This paper considers a problem of testing, from a finite sample, a topological conjugacy of two trajectories coming from dynamical systems (X, f ) and (Y, g). More precisely, given x1, . . . , xn \subset X and y1, . . . , yn \subset Y such that xi+1 = f (xi) and yi+1 = g(yi) as well as h : X \rightarrow Y, we deliver a number of tests to check if f and g are topologically conjugated via h. The values of the tests are close to zero for systems conjugate by h and large for systems that are not. Convergence of the test values, in the case when the sample size goes to infinity, is established. We provide a number of numerical examples indicating scalability and robustness of the presented methods. In addition, we show howthe presented method gives rise to a test of sufficient embedding dimension, mentioned in Takens' embedding theorem. Our methods also apply to the situation when we are given two observables of deterministic processes, of a form of one or higher dimensional time series. In this case, their similarity can be assessed by comparing the dynamics of their Takens' reconstructions. Finally, we include a proof-of-concept study using the presented methods to search for an approximation of the homeomorphism conjugating given systems.

  • Tetracycline degradation for wastewater treatment based on ozone nanobubbles advanced oxidation processes (AOPs) – Focus on nanobubbles formation, degradation kinetics, mechanism and effects of water composition
    • Priya Koundle
    • Neelkanth Nirmalkar
    • Malwina Momotko
    • Sławomir Makowiec
    • Grzegorz Boczkaj
    2024 Pełny tekst CHEMICAL ENGINEERING JOURNAL

    Presence of pharmaceuticals, especially antibiotics, in industrial and domestic effluents causes serious damage to the environment. Classic wastewater treatment processes, in particular conventional biological treatment methods, are not sufficient to rapidly eliminate antibiotics. Typically, Advanced Oxidation Processes (AOPs) based on activation of hydrogen peroxide, ozone or persulfate for formation of particular type of radical species or singlet oxygen are used. A one of cutting-edge technologies to increase effectiveness of AOPs based on ozone are nanobubbles based processes. Thus, this paper focuses on utilization of ozone in the form of nanobubbles for degradation of tetracycline (TC). The effects of several reaction parameters, such as antibiotic concentration, ozone intake, pH, presence of salts, were investigated. This study revealed that the presence of ozone nanobubbles had a substantial positive impact on the degradation of TC. This improvement may be attributed to the enhanced mass transfer and the production of reactive radicals that occur during the collapse of the nanobubbles. Identification of Reactive Oxygen Species (ROS) revealed a significant contribution of hydroxyl radicals in the degradation of the antibiotic. AOP based on O3 nanobubbles generated mostly hydroxyl (•OH) and superoxide anion (O2•–) radicals providing 100 % degradation of 100 mg/L TC within 20 min at 8 mg/L ozone concentration. Based on identified by LC-MS intermediates a detailed degradation mechanism has been described. Degradation of TC and intermediates transformations included methylation, hydroxylation, ring-opening steps as well as cleavage of C-N bonds. This research introduces a novel technique combining nanobubbles with advanced oxidation processes (AOPs), which is anticipated to provide enhanced efficiency and environmental sustainability.

  • The Application of a Mobile Unmanned Device for Monitoring Water and Sediment Pollution in the Port of Gdynia
    • Aleksandra Bojke
    • Katarzyna Galer-Tatarowicz
    • Agnieszka Flasińska
    • Andrzej Chybicki
    • Zbigniew Łubniewski
    • Jadwiga Kargol
    • Dominika Ostrowska
    • Agnieszka Cichowska
    2024 Pełny tekst Water

    Pollution in the Port of Gdynia can encompass various types of substances and contaminants that affect the quality of water and sediment in this region. Ships entering and leaving the port can release pollutants such as oil, fuel, waste, and chemicals into the water. Controlling and monitoring these pollutants is a crucial part of environmental stewardship. In recent years, uncrewed units have been increasingly in use for in situ water and sediment sampling. Boat-based water sampling crews face significant safety risks at sea. Eliminating the need for a boat-based sampling crew, uncrewed units allow sampling from locations that are difficult to access by traditional sampling methods. To validate the HydroDron-1 method, water samples and bottom sediments were collected from five basins in the Port of Gdynia using the HydroDron-1 method and accredited sampling methods. The values of measured parameters were similar for both methods. Using the HydroDron-1 method at the Port of Gdynia has the potential to improve safety while reducing sampling costs and increasing data collection. The project was implemented as part of the POLNOR 2019 Call program, announced by the National Center for Research and Development (NCRD): “Marine port surveillance and observation system using mobile unmanned research units” NOR/POLNOR/MPSS/0037/2019.

  • The Application of Fluidic Sealing in Shrouded Gas Turbine Blades
    • Filip Wasilczuk
    • Paweł Flaszyński
    • Piotr Doerffer
    • Krzysztof Marugi
    • Tomasz Borzęcki
    2024 Pełny tekst JOURNAL OF TURBOMACHINERY-TRANSACTIONS OF THE ASME

    This paper presents a study conducted on a new gas turbine designed to limit leakage in the labyrinth seal. The slots in the fin are used to generate a bypass flow, which obstructs the flow in the gap above the fin. The method was tested numerically and experimentally beforehand using a simplified model without rotation or blade passages. In this paper, the validation of the method using a model of a turbine stage is shown. Reynolds-averaged Navier–Stokes simulations using two turbulence models—Spalart–Allmaras (SA) and k-ω EARSM—were conducted. Comparisons of leakage flow and stage efficiency for reference and fluidic sealing configurations are presented. Fluidic sealing configuration is effective and reduces the leakage flow by 13–18.5% (depending on the turbulence model). The analysis of the flow structure in the seal region revealed that the use of fluidic sealing resulted in significant circumferential flow anisotropy.

  • The Assessment of the Influence of Low-Frequency Electromagnetic Fields Originated from the Power Infrastructure on Humans’ Health
    • Leszek Litzbarski
    • Marek Olesz
    • Grzegorz Redlarski
    • Piotr Tojza
    • Arkadiusz Żak
    • Emanuel Gifuni
    • Zuzanna Cieślikowska
    • Mieszko Czapliński
    2024 Applied Sciences-Basel

    The objective of this study is to assess the impact of low-frequency electromagnetic fields (LF EMFs) generated by power infrastructure on the nearby environment. Measurements of electric (E) and magnetic (H) field intensities were conducted around high-voltage power lines, transformer stations and facilities related to them. Numerical simulations were also performed to model the distribution of the field values around real buildings in close proximity to power delivery systems. Given the ongoing scientific debate regarding the effects of EMFs on living organisms, the current analysis was based on the existing standards—particularly ICNIRP 2010 guidelines, which set the maximum allowable E and magnetic induction (B) values at 5 kV/m and 200 μT, respectively. Stricter national regulations were also examined, such as Poland’s 1 kV/m E limit in residential areas and Belgium’s 10 μT limit for B. The results showed that while most cases complied with ICNIRP 2010 standards, certain stricter local regulations were exceeded. Specifically, 9 of 14 cases exceeded Poland’s E limits, and 8 failed to meet Belgium’s B requirements. Only in one place—a warehouse near 110 kV power lines (in a critical case)—the ICNIRP limit B was exceeded. These findings underscore the variability in regulatory standards and highlight the need for localized assessments of EMF exposure.

  • The “autumn effect” in the gold market—does it contradict the Adaptive Market Hypothesis?
    • Marcin Potrykus
    • Urszula Augustynowicz
    2024 Pełny tekst International Journal of Management and Economics

    The present study aims to verify the autumn effect in the gold market, first presented 10 years ago by Dirk Baur in the paper “The autumn effect of gold” and to investigate the calendar effects occurring for other precious metals. This empirical research is presented in a way to place the results obtained in the context of the Efficient Market Hypothesis (EMH) and the more current Adaptive Market Hypothesis (AMH). The study was conducted as an extended reproduction of the Baur study. The main conclusion is that, the autumn effect on the gold market has been reversed and replaced by the winter effect, which is linked to the AMH. An equally interesting calendar effect was observed for silver. Platinum and palladium saw an increase in prices in January, but given the patterns in the gold market, it is very likely that this phenomenon will also change over time.

  • The Belt and Road Initiative and export variety: 1996–2019
    • Yuxin Lu
    • Joanna Wolszczak-Derlacz
    2024 Asian-Pacific Economic Literature

    This study examines the association between the Belt and Road Initiative (BRI) and export variety (EV). We propose three hypotheses on how BRI may foster export markets (destinations) or export product lines. The estimates are based on a dataset constructed specifically for this analysis, covering 183 countries and linked with trade data from 1996 to 2019. We apply the instrumental variable (IV) approach in regressions for covering the endogeneity. The results indicate that participation in BRI is negatively related to EV. Specifically, we find evidence that, on average, BRI participants have less EV (by product and by destination) and greater export concentration. As regards participation in the Asian Infrastructure Investment Bank and BRI meanwhile (AIIB_BRI and AIIB_MOU), the results show a more negative effect. And there are heterogeneous effects of BRI across different economies and sectors

  • The bile salt/phospholipid ratio determines the extent of in vitro intestinal lipolysis of triglycerides: Interfacial and emulsion studies
    • Katarzyna Kłosowska
    • Teresa Del Castillo Santaella
    • Julia Maldonado-Valderrama
    • Adam Macierzanka
    2024 FOOD RESEARCH INTERNATIONAL

    This study focused on the protein-stabilised triglyceride (TG)/water interfaces and oil-in-water emulsions, and explored the influence of varying molar ratios of bile salts (BSs) and phospholipids (PLs) on the intestinal lipolysis of TGs. The presence of these two major groups of biosurfactants delivered with human bile to the physiological environment of intestinal digestion was replicated in our experiments by using mixtures of individual BSs and PLs under in vitro small intestinal lipolysis conditions. Conducted initially, retrospective analysis of available scientific literature revealed that an average molar ratio of 9:4 for BSs to PLs (BS/PL) can be considered physiological in the postprandial adult human small intestine. Our experimental data showed that combining BSs and PLs synergistically enhanced interfacial activity, substantially reducing oil-water interfacial tension (IFT) during interfacial lipolysis experiments with pancreatic lipase, especially at the BS/PL–9:4 ratio. Other BS/PL molar proportions (BS/PL–6.5:6.5 and BS/PL–4:9) and an equimolar amount of BSs (BS–13) followed in IFT reduction efficiency, while using PLs alone as biosurfactants was the least efficient. In the following emulsion lipolysis experiments, BS/PL–9:4 outperformed other BS/PL mixtures in terms of enhancing the TG digestion extent. The degree of TG conversion and the desorption efficiency of interfacial material post-lipolysis correlated directly with the BS/PL ratio, decreasing as the PL proportion increased. In conclusion, this study highlights the crucial role of biliary PLs, alongside BSs, in replicating the physiological function of bile in intestinal lipolysis of emulsified TGs. Our results showed different contributions of PLs and BSs to lipolysis, strongly suggesting that any future in vitro studies aiming to simulate the human digestion conditions should take into account the impact of biliary PLs – not just BSs – to accurately mimic the physiological role of bile in intestinal lipolysis. This is particularly crucial given the fact that existing in vitro digestion protocols typically focus solely on applying specific concentrations and/or compositions of BSs to simulate the action of human bile during intestinal digestion, while overlooking the presence and concentration of biliary PLs under physiological gut conditions.

  • The biological role of prolyl oligopeptidase and the procognitive potential of its peptidic inhibitors from food proteins
    • Antoni Taraszkiewicz
    • Izabela Sinkiewicz
    • Agata Sommer
    • Hanna Staroszczyk
    2024 Pełny tekst CRITICAL REVIEWS IN FOOD SCIENCE AND NUTRITION

    Prolyl oligopeptidase (POP) is a conserved serine protease belonging to proline-specific peptidases. It has both enzymatic and non-enzymatic activity and is involved in numerous biological processes in the human body, playing a role in e.g., cellular growth and differentiation, inflammation, as well as the development of some neurodegenerative and neuropsychiatric disorders. This article describes the physiological and pathological aspects of POP activity and the state-of-art of its peptidic inhibitors originating from food proteins, with a particular focus on their potential as cognition-enhancing agents. Although some milk, meat, fish, and plant protein-derived peptides have the potential to be applied as natural, procognitive nutraceuticals, their effectiveness requires further evaluation, especially in clinical trials. We demonstrated that the important features of the most promising POP-inhibiting peptides are very short sequence, high content of hydrophobic amino acids, and usually the presence of proline residue.

  • The chemistry, properties and performance of flame-retardant rubber composites: Collecting, analyzing, categorizing, machine learning modeling, and visualizing
    • Paulina Wiśniewska
    • Elnaz Movahedifar
    • Krzysztof Formela
    • Mohammad Naser-moghadasi
    • Henri Vahabi
    • Mohammad Saeb
    2024 COMPOSITES SCIENCE AND TECHNOLOGY

    Rubbers combine the flexibility with mechanical strength, supporting myriad applications, but suffer from inherent flammability. Formulation and production of flame-retardant rubber composites (FRRCs) have intensively been practiced over years, but not comprehensively reviewed. This necessity has outlined collecting, analyzing, screening, classifying, and interpreting the literature with the aim of classifying the FRRCs. We quantified and visualized the flame retardancy of natural and synthetic FRRCs by grouping FRRCs based on their flame retardants (FRs) among green, mineral, phosphorus-based, nitrogen-based, carbonaceous, and hybrids of two or more types. Available data on cone calorimetry, limited oxygen index (LOI), and UL-94 of FRRCs were carefully extracted and plotted. Flame Retardancy Index (FRI) was used to specify the Poor, Good, or Excellent classes of flame retardancy in association with the chemistry and concentration of FRs to broaden the future innovation avenues. Machine Learning (ML) modeling enabled visualization of flame retardancy landscapes of natural and synthetic rubbers in terms of the chemistry and concentration of FRs. Overall, a downward trend in mechanical properties of FRRCSs against FRs amount was oxplored. This study proposed a general guideline for recognizing gaps in previous investigations and mechanistic interpretations. In conclusion, we highlight that the future FRRCs should take advantage of hybridizing FRs in order to meet the fire safety requirements, which would be possible by the innovative colorful checkered flame retardancy chart presented in this survey.

  • The clamping selection method to reduce the vibration of large-size workpieces during the face milling process
    • Krzysztof Kaliński
    • Marek Galewski
    • Natalia Stawicka-Morawska
    • Krzysztof Jemielniak
    • Michał Mazur
    2024 Pełny tekst Bulletin of the Polish Academy of Sciences-Technical Sciences

    The article introduces a method for selecting the best clamping conditions to obtain vibration reduction during milling of large-size workpiece. It is based on experimental modal analysis performed for a set of assumed, fixing conditions of a considered workpiece to identify Frequency Response Functions (FRFs) for each tightening torque of the mounting screws. Simulated plots of periodically changing nominal cutting forces are then calculated. Subsequently, by multiplying FRF and spectra of cutting forces, a Clamping Selection Function (CSF) is determined and, thanks to this function, vibration Root Mean Square (RMS) is calculated resulting in Clamping Selection Indicator (CSI) that indicates the best clamping of the workpiece. The method's effectiveness was evidenced by assessing the RMS value of the vibration level observed in time domain during the real-time face milling process of an large-sized exemplary item. The proposed approach may be useful for seeking the best conditions for fixing the workpiece on the table.

  • THE CONCEPT AND THE STATE OF RESEARCH ON THE PERFORMANCE OF FAMILY BUSINESSES
    • Ewelina Sokołowska
    • Daniel Boehlich
    • Anna Dziadkiewicz
    2024 Pełny tekst Zeszyty Naukowe. Organizacja i Zarządzanie / Politechnika Śląska

    Purpose: This study's primary goal is to present the theoretical concept of family enterprises. Specifically, the results of earlier studies and the issues facing this field of research now will be described. The article also examines the underlying impacts that family control has on business management in order to fill the research gap left by earlier studies on the performance differences between family and non-family enterprises. A thorough analysis of the literature revealed that family firms place equal value on non-financial performance as they do on financial performance. Design/methodology/approach: The study's survey focuses on critical analysis methods used in the literature. Critical theoretical analysis will also be accompanied by comparative, analytical and monographic methods implied to draw conclusions on further research directions in the family business sector. Findings: The current work makes a significant contribution by broadening the theoretical foundation for family business research. Therefore, a sound foundation for the explanation of distinctive strategic management components may be established using the behavior-oriented approach, stakeholder theory, target composition, and balanced scorecard approach. Research limitations/implications: Unconfirmed theories may be examined more closely, particularly in a modified setting. Practical implications: The findings of this theoretical study are not only important for business research but also for business practice. The study is primary addressed to the top management of family and non-family businesses. Moreover, potential investors, banks and consultants could benefit from the results of this study. Originality/value: This study aims to provide a better understanding of the relationship between the variables of family influence, goal setting and selection of key performance indicators and organizational performance and business success. That is how a contribution can be made to the ongoing discussion about the success of family businesses and its underlying factors. Keywords: Family business, Goal setting, Business performance, Small and medium-sized enterprises. Category of the paper: literature review.

  • The Crowd as a Source of Knowledge - From User Feedback to Fulfilling Requirements
    • Anna Baj-Rogowska
    2024 Pełny tekst

    Crowd-based and data-intensive requirements engineering (RE) strategy is an approach for gathering and analyzing information from the general public or the so-called crowd to derive validated user requirements. This study aims to conceptualize the process of analyzing information from a crowd to achieve the fulfillment of user requirements. The created model is based on the ADO framework (Antecedents-Decisions-Outcomes). In the empirical part, we chose the Instagram mobile app and user feedback on it as a source of data for the validation of our approach. For extracting antecedents from user feedback, we applied the Latent Dirichlet Allocation (LDA), and then sentiment analysis was performed for each topic to prioritize the most urgent tasks delegated by the crowd. The main findings of our study reveal that using the wide spectrum of experience and knowledge of users (the wisdom of the crowd) from user opinions helps uncover different aspects that are helpful during software development. The conceptualization based on the ADO framework reflects and captures this process well. Thus, crowdsourcing is an alternative to traditional methods and techniques for requirements engineering.

  • The culture of excellence and its dimensions in higher education
    • Małgorzata Wiśniewska
    • Piotr Grudowski
    2024 The TQM Journal

    Purpose To recognize the existing state of knowledge on a culture of excellence (CoE) in higher education institutions (HEIs) and to define the CoE in HEI and the dimensions that make up that culture. A subsidiary goal is to propose a qualitative tool to measure CoE maturity. Design/methodology/approach The study was based on the qualitative method, the preferred reporting system of systematic reviews and meta-analysis (PRISMA). Next, the conceptual work method was used. Findings A research gap in the topic of CoE in HE has been confirmed. The CoE's own definition has been proposed, as well as a set of seven dimensions that comprise it, such as: Clear vision, mission and goals for excellence; Leadership oriented to excellence; Employee engagement; Human resources management; Meeting and exceeding student and staff expectations; Continuous improvement of processes through innovation and excellent practices; and Partnership and teamwork for improvement. Research limitations/implications The study research was limited to open-access articles. Therefore, in the future, the search can be broadened to include monographs or doctoral dissertations, and other peer-reviewed studies. The research implications are related to the originality of our work and the proposals of two concepts – a CoE model and a CoE maturity assessment tool. Practical implications Leaders at universities, e.g. rectors and deans, can take into account the identified dimensions and progressively provide them as conditions conducive to achieving above-average levels. Originality/value This is the first literature review on CoE in HEIs, which can be considered an original contribution to science and practice. The original contribution of the paper is also the proposal of a CoE conceptual model and a CoE maturity assessment tool.

  • The determinants of European universities patenting and co‑patenting with companies
    • Joanna Wolszczak-Derlacz
    2024 JOURNAL OF TECHNOLOGY TRANSFER

    This study examines the determinants of European universities patenting and co-patenting with companies. The analysis takes into account more than 400 universities from 17 countries over the period 2011–2018. We test several determinants of the commercial activity of universities, such as: student enrolment (size), age, public or private nature of the institution, students per academic staff, publications per academic staff (research orientation), non-academic staff per academic staff, funding structure (core and third-party budget) and prior patent activity. We estimate two-part models with zero-inflated negative binomial/zero-inflated beta regressions, which estimate separately the impact of the determinant of patenting (count data/proportion of joint company-university patents) and the probability of no patenting. The results indicate that the main determinants of universities patenting and co-patenting with companies are: size, age, research orientation and funding structure. As for patents per se, the determinants of starting patenting are the same as continuing patenting, while for joint company-university patents, most of the determinants differently affect starting joint-patenting than increasing the proportion of co-patents with companies in all patents

  • The Development of Toxoplasma gondii Recombinant Trivalent Chimeric Proteins as an Alternative to Toxoplasma Lysate Antigen (TLA) in Enzyme-Linked Immunosorbent Assay (ELISA) for the Detection of Immunoglobulin G (IgG) in Small Ruminants
    • Bartłomiej Tomasz Ferra
    • Maciej Chyb
    • Karolina Sołowińska
    • Lucyna Holec-Gąsior
    • Marta Skwarecka
    • Karolina Baranowicz
    • Justyna Gatkowska
    2024 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    This study presents an evaluation of seventeen newly produced recombinant trivalent chimeric proteins (containing the same immunodominant fragment of SAG1 and SAG2 of Toxoplasma gondii antigens, and an additional immunodominant fragment of one of the parasite antigens, such as AMA1, GRA1, GRA2, GRA5, GRA6, GRA7, GRA9, LDH2, MAG1, MIC1, MIC3, P35, and ROP1) as a potential alternative to the whole-cell tachyzoite lysate (TLA) used in the detection of infection in small ruminants. These recombinant proteins, obtained by genetic engineering and molecular biology methods, were tested for their reactivity with specific anti-Toxoplasma IgG antibodies contained in serum samples of small ruminants (192 samples of sheep serum and 95 samples of goat serum) using an enzyme-linked immunosorbent assay (ELISA). The reactivity of six recombinant trivalent chimeric proteins (SAG1-SAG2-GRA5, SAG1-SAG2-GRA9, SAG1-SAG2-MIC1, SAG1-SAG2-MIC3, SAG1-SAG2-P35, and SAG1-SAG2-ROP1) with IgG antibodies generated during T. gondii invasion was comparable to the sensitivity of TLA-based IgG ELISA (100%). The obtained results show a strong correlation with the results obtained for TLA. This suggests that these protein preparations may be a potential alternative to TLA used in commercial tests and could be used to develop a cheaper test for the detection of parasite infection in small ruminants.

  • The Digital Research Revolution
    • Anna Trzaskowska
    • Paulo Botelho Pires
    • José Duarte Santos
    2024

    Marketing research has been through a significant evolution in the digital age. The evolution of technology has had a cross-cutting impact on the discipline. In light of this, a perspective is presented on how this impact has been reflected in marketing research. A review of traditional techniques is provided, followed by a description of the reconceptualization of traditional methods resulting from the application of new technologies. This is followed by a presentation of new methods that have emerged as a result of technological advances and because there is a new context in which they need to be studied. Finally, the implications for analyzing data resulting from new algorithms and technologies are also discussed.

  • The effect of 1,4-butanediol on the efficiency of CO2 absorption and inhibition of NH3 escape during the mineral carbonation of gypsum
    • Temesgen Amibo
    • Donata Konopacka-Łyskawa
    2024 Pełny tekst

    This study explored the optimal concentration of 1,4-butanediol for maximizing CO2 absorption and minimizing ammonia desorption. Mineral carbonation of gypsum slurry was carried out in a bubble reactor with a magnetic stirrer maintaining constant speed for 1 hour. The gas introduced to the reactor was a mixture of CO2 and air. The gas flow was controlled by the mass controllers. Gas sensors were used to determine the concentration of CO2 and NH3 in the outlet gas. The initial and final pH values were measured. The liquid phase was ammonia solutions at a concentration of 1.69 mol.dm-3 with the addition of varying concentrations of 1,4-butanediol (ranging from 0.1 to 0.5 mol. dm-3). The ratio of gypsum to liquid phase was maintained as 1:14 (kg. dm-3). Based on measured CO2 and NH3 concentrations, the efficiency of carbon dioxide absorption and the efficiency of ammonia escape inhibition were calculated.

  • The effect of aeration mode (intermittent vs. continuous) on nutrient removal and greenhouse gas emissions in the wastewater treatment plant of Corleone (Italy)
    • Giorgio Mannina
    • Paulo Marcelo Bosco Mofatto
    • Alida Cosenza
    • Daniele Trapani Di
    • Hazal Gulhan
    • Antonio Mineo
    • Jacek Mąkinia
    2024 Pełny tekst SCIENCE OF THE TOTAL ENVIRONMENT

    The paper reports the results of an experimental study aimed at comparing two configurations of a full-scale wastewater treatment plant (WWTP): conventional activated sludge (CAS) and oxic-settling-anaerobic process (OSA) with intermittent aeration (IA). A comprehensive monitoring campaign was carried out to assess multiple parameters for comparing the two configurations: carbon and nutrient removal, greenhouse gas emissions, respirometric analysis, and sludge production. A holistic approach has been adopted in the study with the novelty of including the carbon footprint (CF) contribution (as direct, indirect and derivative emissions) in comparing the two configurations. Results showed that the OSA-IA configuration performed better in total chemical oxygen demand (TCOD) and ortho-phosphate (PO4-P) removal. CAS performed better for Total Suspended Solids (TSS) removal showing a worsening of settling properties for OSA-IA. The heterotrophic yield coefficient and maximum growth rate decreased, suggesting a shift to sludge reduction metabolism in the OSA-IA configuration. Autotrophic biomass showed a reduced yield coefficient and maximum growth yield due to the negative effects of the sludge holding tank in the OSA-IA configuration on nitrification. The OSA-IA configuration had higher indirect emissions (30.5 % vs 21.3 % in CAS) from additional energy consumption due to additional mixers and sludge recirculation pumps. The CF value was lower for OSA-IA than for CAS configuration (0.36 kgCO2/m3 vs 0.39 kgCO2/m3 in CAS).