Grzegorz Łagód

MEASUREMENT OF ACTIVATED SLUDGE PARTICLE DIAMETERS USING LASER DIFFRACTION METHOD

Abstract The paper presents a study on the possibility of using the laser diffraction method for measuring the size of the activated sludge particles. Susceptibility of the particles to mechanical disintegration, dependent on the programmed value of stirring intensity, was observed (stirring was caused by required dynamic flow of analysed suspension through the measurement unit). According to the conclusions presented in this paper, it may be assumed that the laser diffraction method can be applied for measurement of activated sludge particle diameters under the following conditions: 1) the size of activated sludge particles measured by the laser diffraction method is not a real value, but after standardisation of measurement conditions can be treated as a parameter describing the sludge; 2) the particle diameters of activated sludge should be stabilised before the measurement, eg by mixing in the measurement unit or by ultrasound waves application. Abstrakt Praca dotyczy oceny możliwości wykorzystania dyfrakcji laserowej do badania rozmiarów kłaczków osadu czynnego. W czasie pomiarów zaobserwowano podatność analizowanych cząstek na zniszczenie mechaniczne zależną od zaprogramowanej intensywności mieszania (mieszanie i przepompowywanie jest wymagane w celu wymuszenia przepływu analizowanych zawiesin przez układ pomiarowy). Na podstawie wniosków opracowanych na podstawie prowadzonych badań można stwierdzić, iż metoda dyfrakcji laserowej może być stosowana do pomiarów rozmiarów kłaczków osadu czynnego pod następującymi warunkami: rozmiary kłaczków oraz pozostałych elementów osadu czynnego uzyskane w czasie pomiarów nie mogą być traktowane jako wartość bezpośrednia opisująca rozmiary kłaczka, lecz po standaryzacji warunków pomiarowych może być traktowana jako ilościowy parametr opisujący właściwości osadu czynnego. Przed pomiarem metodą dyfrakcji laserowej osad czynny powinien być uprzednio stabilizowany na przykład za pomocą mieszania w układzie pomiarowym bądź też za pomocą ultradźwięków.

Comparison of the dynamics of natural biodegradation of petrol and diesel oil in soil

AbstractContamination of soil with petroleum products is a major environmental problem. Therefore, one of the issues related to environmental protection is assessment of the ability of soil microbial populations to biodegrade petroleum-derived substances. The aim of the study was to compare the dynamics and fractionation of carbon isotopes during biodegradation of selected petroleum products (petrol and diesel) in soil characterised by optimal humidity for plants. The analyses were performed on soil material sampled from the arable layer of a fertile soil (chernozem) in central Poland. The soil samples were treated with two petroleum substances, i.e. unleaded 95-octane petrol and diesel fuel. The dynamics of changes was assessed by monitoring carbon dioxide content and oxygen content in the headspace over the soil surface. Additionally, the ratio of δ13C carbon isotopes was measured in the substrates added (petrol and diesel) and in CO2 emitted to the atmosphere. In summary, it should be concluded that th...

Community Composition and Abundance of Protozoa Under Different Concentration Of Nitrogen Compounds at “Hajdow” Wastewater Treatment Plant / Zbiorowiska Pierwotniaków I Ich Liczebność W Oczyszczalni Ścieków „Hajdów” Przy Różnych Stężeniach Związków Azotu

Abstract The protists notably ciliates and testate amoebas in the conditions of modernized wastewater treatment plants “Hajdow” (Lublin, Poland) and the nitrogen removal efficiency were studied. Sampling took place every week during the period of August-September 2010. The total of 31 taxa of ciliates and 3 taxa of testate amoebas were identified. Most of the species were registered during the whole research period. Significant abundance reached the following species: Acineria uncinata, Aspidisca cicada, Aspidisca lynceus, Vorticella aquadulcis, Vorticella infusionum, Arcella vulgaris, Euglypha acanthophora and Pyxidicula operculata. In September increase in efficiency of nitrogen removal process was registered. The research shows that the increase of nitrogen reduction efficiency was accompanied by increase of ciliates quantity, mainly due to peritrichid ciliates. Abstrakt Przedstawiono analizę zgrupowań pierwotniaków obejmującą orzęski oraz ameby skorupkowe, zasiedlające kolejne urządzenia głównego ciągu technologicznego oczyszczalni ścieków „Hajdów” na tle zmian w stężeniach związków azotu. Badania prowadzono po modernizacji części biologicznej realizowanej w celu podniesienia skuteczności usuwania ze ścieków związków biogennych, a w szczególności związków azotu. Pobór próbek prowadzony był raz w tygodniu w okresie sierpień-wrzesień 2010 roku. W badanym materiale biologicznym wyodrębniono 31 gatunków orzęsków oraz 3 gatunki ameb skorupkowych. Większość ze wspomnianych gatunków pierwotniaków odnotowywana była przez cały okres badań. Najbardziej licznie w analizowanym materiale biologicznym reprezentowane były następujące gatunki: Acineria uncinata, Aspidiscacicada, Aspidisca lynceus, Vorticella aquadulcis, Vorticella infusionum, Arcella vulgaris, Euglyphaacanthophora i Pyxidicula operculata. We wrześniu odnotowany został wzrost skuteczności procesu usuwania związków azotu. Prezentowane badania wskazują, iż wzrostowi stopnia usuwania ze ścieków związków azotu towarzyszył wzrost ilości orzęsków odnoszący się głównie do form peritricha.

Estimation of building material moisture using non-invasive TDR sensors

The article presents the noninvasive attempt to measure moisture of building materials with the use of electric methods. Comparing to the other techniques of moisture detection like chemical or physical, the electric methods enable quick moisture estimation and they seem to be a suitable solution to monitor moisture changes. Most of electric moisture meters are the capacitance and resistance sensors. A perspective technique to determine moisture of building materials and barriers is Time Domain Reflectometry (TDR) method. This method has been successfully applied for moisture determination of the soils and since a few years has been used to measure moisture of building materials. The attempts to measure moisture of building materials require modification of traditional TDR sensor construction and extra calibration procedures. Sensors applied for building materials, comparing to the traditional ones are noninvasive. The advantages of surface sensors proposed in this article are the following: no influence ...

Impact of optical indices on particle size distribution of activated sludge measured by laser diffraction method

Abstract The important factors that strongly influence the particle size distributions measured by the laser diffraction method are the optical parameters of the suspension (refractive index and absorption coefficient). Knowledge of the values of these parameters is necessary for Mie theory. Mie theory is applied for conversion of the intensity of light recorded on detectors into particle size distribution (PSD) of tested material. Both wastewater and activated sludge are mixtures of a variety of elements (mineral or organic, including living organisms). In practice, it is not possible to define clearly the values of the optical parameters, as the composition of the suspension changes over time. The aim of the study was to estimate the impact of assumed values of the optical parameters on particle size distributions obtained. The PSDs of suspensions sampled in different stages of wastewater treatment are the most reproducible when the following optical parameters are defined: absorption coefficients - 1.0 and the refractive index - 1.52. Abstrakt Czynnikami, które w istotny sposób wpływają na rozkłady granulometryczne wyznaczane za pomocą dyfrakcji laserowej, są parametry optyczne mierzonej zawiesiny (współczynnik załamania światła oraz współczynnik absorpcji). Znajomość wartości tych parametrów jest niezbędna przy zastosowaniu teorii Mie. Teoria Mie jest wykorzystywana do przeliczenia intensywności światła zmierzonego na detektorach na rozkład granulometryczny (PSD) badanego materiału. Zarówno ścieki, jak i osad czynny są mieszaninami bardzo różnych składników (mineralnych i organicznych, w tym żywych organizmów). W praktyce nie ma możliwości określenia rzeczywistych wartości parametrów optycznych mieszanin, tym bardziej, że ich skład zmienia się w czasie. Celem niniejszej pracy było określenie wpływu założonych wartości parametrów optycznych na uzyskiwane rozkłady granulometryczne. Rozkłady granulometryczne zawiesin pobranych na różnych etapach oczyszczania ścieków są najbardziej powtarzalne dla następujących wartości współczynników optycznych: współczynnika absorpcji - 1,0 i współczynnika załamania światła - 1,52.

Classification of buildings mold threat using electronic nose

Mold is considered to be one of the most important features of Sick Building Syndrome and is an important problem in current building industry. In many cases it is caused by the rising moisture of building envelopes surface and exaggerated humidity of indoor air. Concerning historical buildings it is mostly caused by outdated raising techniques among that is absence of horizontal isolation against moisture and hygroscopic materials applied for construction. Recent buildings also suffer problem of mold risk which is caused in many cases by hermetization leading to improper performance of gravitational ventilation systems that make suitable conditions for mold development. Basing on our research there is proposed a method of buildings mold threat classification using electronic nose, based on a gas sensors array which consists of MOS sensors (metal oxide semiconductor). Used device is frequently applied for air quality assessment in environmental engineering branches. Presented results show the interpretation of e-nose readouts of indoor air sampled in rooms threatened with mold development in comparison with clean reference rooms and synthetic air. Obtained multivariate data were processed, visualized and classified using a PCA (Principal Component Analysis) and ANN (Artificial Neural Network) methods. Described investigation confirmed that electronic nose – gas sensors array supported with data processing enables to classify air samples taken from different rooms affected with mold.Mold is considered to be one of the most important features of Sick Building Syndrome and is an important problem in current building industry. In many cases it is caused by the rising moisture of building envelopes surface and exaggerated humidity of indoor air. Concerning historical buildings it is mostly caused by outdated raising techniques among that is absence of horizontal isolation against moisture and hygroscopic materials applied for construction. Recent buildings also suffer problem of mold risk which is caused in many cases by hermetization leading to improper performance of gravitational ventilation systems that make suitable conditions for mold development. Basing on our research there is proposed a method of buildings mold threat classification using electronic nose, based on a gas sensors array which consists of MOS sensors (metal oxide semiconductor). Used device is frequently applied for air quality assessment in environmental engineering branches. Presented results show the interpretati...

Analysis of gas sensors array signals for evaluation of mold contamination in buildings

Mold is considered to be one of the most important features of Sick Building Syndrome (SBS) and is an important problem in building sector. In numerous cases it is caused by the rising moisture of building envelopes and overstated humidity of indoor air. Fungal contamination is normally evaluated using standard biological methods which are time-consuming and require a lot of manual labor. But also, fungi emit Volatile Organic Compounds (VOC) that can be detected in the indoor air using several techniques of detection e.g. chromatography. VOCs can be also detected using gas sensors arrays. All arrays of sensors generate particular electric signals that ought to be analyzed using statistical methods of interpretation. This work is focused on the attempt to apply unsupervised and supervised statistical classifying models in the evaluation of signals from gas sensors array to analyze the air from various types of the buildings. Basing on our research there is proposed buildings mold threat evaluation using MOS (Metal Oxide Semiconductor) sensors array. Presented results show the interpretation sensors readouts of indoor air sampled in lodgings threatened with mold development in comparison with clean reference one and synthetic air.Mold is considered to be one of the most important features of Sick Building Syndrome (SBS) and is an important problem in building sector. In numerous cases it is caused by the rising moisture of building envelopes and overstated humidity of indoor air. Fungal contamination is normally evaluated using standard biological methods which are time-consuming and require a lot of manual labor. But also, fungi emit Volatile Organic Compounds (VOC) that can be detected in the indoor air using several techniques of detection e.g. chromatography. VOCs can be also detected using gas sensors arrays. All arrays of sensors generate particular electric signals that ought to be analyzed using statistical methods of interpretation. This work is focused on the attempt to apply unsupervised and supervised statistical classifying models in the evaluation of signals from gas sensors array to analyze the air from various types of the buildings. Basing on our research there is proposed buildings mold threat evaluation using MO...

Evaluation of the contact angle and frost resistance of hydrophobised heat-insulating mortars with polystyrene

The aim of the research presented in the paper was to evaluate the feasibility of using hydrophobic preparation based on organosilicon compounds for surface protection on the heat-insulating mortars modified with polystyrene. The work discusses issues related to wettability, absorptivity and frost resistance of the surface layer of mortars. The experimental part pertains to the physical and mechanical properties of polystyrene-modified mortars and the influence of hydrophobic preparation on the contact angle and frost resistance. The frost resistance of mortars was examined following 25 cycles of freezing and thawing. The contact angle of light mortars (θw) was determined before and after the tests of frost resistance, in the function of time using a single measurement liquid. This provided a basis for calculating the surface free energy with Neumann method, characterizing the wettability and adhesion of mortars under normal conditions and with damages resulting from frost weathering. The structure of mor...

The application of the statistical classifying models for signal evaluation of the gas sensors analyzing mold contamination of the building materials

Mold that develops on moistened building barriers is a major cause of the Sick Building Syndrome (SBS). Fungal contamination is normally evaluated using standard biological methods which are time-consuming and require a lot of manual labor. Fungi emit Volatile Organic Compounds (VOC) that can be detected in the indoor air using several techniques of detection e.g. chromatography. VOCs can be also detected using gas sensors arrays. All array sensors generate particular voltage signals that ought to be analyzed using properly selected statistical methods of interpretation. This work is focused on the attempt to apply statistical classifying models in evaluation of signals from gas sensors matrix to analyze the air sampled from the headspace of various types of the building materials at different level of contamination but also clean reference materials.