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1

Microscopic Studies of Activated Sludge Supported by Automatic Image Analysis Based on Deep Learning Neural Networks

Dziadosz Marcin, Majerek Dariusz, Łagód Grzegorz

Journal of Ecological Engineering

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2024

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Vol. 25, nr 4

360--369

EN

Paper presents microscopic studies of activated sludge supported by automatic image analysis based on deep learning neural networks. The organisms classified as Arcella vulgaris were chosen for the research. They frequently occur in the waters containing organic substances as well as WWTPs employing the activated sludge method. Usually, they can be clearly seen and counted using a standard optical microscope, as a result of their distinctive appearance, numerous population and passive behavior. Thus, these organisms constitute a viable object for detection task. Paper refers to the comparison of performance of deep learning networks namely YOLOv4 and YOLOv8, which conduct automatic image analysis of the afore-mentioned organisms. YOLO (You Only Look Once) constitutes a one-stage object detection model that look at the analyzed image once and allow real-time detection without a marked accuracy loss. The training of the applied YOLO models was carried out using sample microscopic images of activated sludge. The relevant training data set was created by manually labeling the digital images of organisms, followed by calculation and comparison of various metrics, including recall, precision, and accuracy. The architecture of the networks built for the detection task was general, which means that the structure of the layers and filters was not affected by the purpose of using the models. Accounting mentioned universal construction of the models, the results of the accuracy and quality of the classification can be considered as very good. This means that the general architecture of the YOLO networks can also be used for specific tasks such as identification of shell amoebas in activated sludge.

2

Impact of Pharmaceuticals on the Individual Wastewater Treatment System

Makowska Małgorzata, Spychała Marcin, Gajewska Katarzyna

Journal of Ecological Engineering

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2024

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Vol. 25, nr 2

257--266

EN

Intensive economic development causes the risk of introducing the so-called emerging contaminants (EC) into the environment. This group of contaminants includes pharmaceuticals, including non-steroidal anti-inflammatory drugs (NSAIDs), the consumption of which is steadily increasing in Poland as well as worldwide. Such specific contaminants may also cause problems at the stage of biological treatment of wastewater, especially in individual systems that are sensitive to changes in wastewater composition. The study examined an onsite wastewater treatment system based on the activated sludge technology, to which three different pharmaceuticals were dosed in the quantities normally used in therapy. The operation of the biological reactor under these conditions was analysed by comparing contamination indicators at the inlet and outlet of the treatment plant at different doses of pharmaceuticals. It was found that the doses used did not significantly worsen the effects of wastewater treatment, except for paracetamol, which at a dose above 1000 mg/d caused a slight reduction in the efficiency of the facility. The dosed pharmaceuticals also did not deteriorate the sedimentation properties of the activated sludge. Although typical doses of pharmaceuticals do not interfere with the operation of the biological reactor, residual substances and their metabolites may be released into the environment; it is therefore reasonable to consider the introduction of an additional treatment stage to remove micropollutants from the wastewater.

3

Diversity of Peritricha (Ciliophora) in Activated Sludge Depending on the Technology of Wastewater Treatment

Babko Roman, Kuzmina Tatiana, Pliashechnik Volodimir, Zaburko Jacek, Szulżyk-Cieplak Joanna, Łagód Grzegorz

Journal of Ecological Engineering

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2024

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Vol. 25, nr 2

158--166

EN

The representation of Peritricha ciliates was studied in the activated sludge of two wastewater treatment plants (WWTP), one of which operates using a technology that includes alternating aerobic, anoxic and anaerobic conditions in bioreactors (Lublin, Poland), and the other – only aerobic conditions (Sumy, Ukraine). During the study, 14 Peritricha species were identified in the WWTP Lublin, and 13 species were identified in the WWTP Sumy. The similarity of species lists was 81.5% (Sørensen index). On the basis of on the similarity and taking into account the occurrence rate (≥ 60%), a common group of Peritricha species characteristic of the activated sludge from these two types of treatment facilities was identified, which includes 4 species of colonial Peritricha: Carchesium polypinum, Epistylis coronata, Epistylis longicaudatum and Opercularia articulata, and also 4 species of solitary Peritricha: Vorticella aquadulcis, Vorticella convallaria, Vorticella infusionum and Vorticella microstoma. Despite the very high similarity in species composition, statistical analysis of the population structure of Peritricha showed a clear separation of two WWTPs with different wastewater treatment technologies. If there is a significant similarity in the species composition of Peritricha, the species, based on their abundance and occurrence, are divided into two groups, focused on different technological schemes. The population structure of Peritricha responds to the changes in purification technology, showing the changes not so much in species composition as in their quantitative structure. The differences in bioreactor conditions and increased effluent treatment efficiency demonstrated by the WWTP Lublin result in differences in Peritricha species structure, which are reflected in higher Peritricha abundance in WWTP Lublin compared to WWTP Sumy.

4

Możliwości adaptacji osadu czynnego do produktów odpadowych z produkcji alkoholu w celu intensyfikacji procesu biologicznej denitryfikacji na przykładzie komunalnej oczyszczalni ścieków Gdańsk – Wschód

Drewnowski Jakub, Czerwionka Krzysztof, Mąkinia Jacek

Inżynieria Morska i Geotechnika

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2024

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nr 2

51--58

PL

Możliwości adaptacji osadu czynnego do produktów odpadowych z produkcji alkoholu w celu intensyfikacji procesu biologicznej denitryfikacji na przykładzie komunalnej oczyszczalni ścieków Gdańsk - Wschód. Ocena, na podstawie wykonanych wielotygodniowych ciągłych testów w skali technicznej, przydatności produktów odpadowych z produkcji alkoholu do intensyfikacji procesu biologicznej denitryfikacji w typowej oczyszczalni ścieków opartych o metodę osadu czynnego.

EN

The adaptability of activated sludge to waste products from alcohol production in order to intensify the process of biological denitrification on the example of the municipal WWTP Gdańsk - Wschód. The assessment, on the basis of several weeks of continuous scale tests carried out technical development, the suitability of waste products from the production of alcohol to intensify the process of biological denitrification in conventional WWTP, that use an activated sludge system.

5

Zastosowanie techniki FTIR i metod chemometrycznych do oceny procesu biologicznego oczyszczania ścieków komunalnych osadem czynnym

Piaskowski Krzysztof, Walendzik Bartosz

Gaz, Woda i Technika Sanitarna

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2024

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Nr 1

32--39

PL

Biologiczny proces osadu czynnego jest najpopularniejszą metodą stosowaną w licznych oczyszczalniach ścieków, która z reguły pozwala na uzyskanie wymaganego efektu ekologicznego. Jednakże charakteryzuje się ona również pewną niestabilnością uzyskiwanych efektów zależną od warunków i parametrów, na które częściowo eksploatator nie ma wpływu. Dlatego też poszukuje się szybkich technik analitycznych do kontroli i oceny osadu czynnego, które w przypadku pojawienia się nieprawidłowości w komorach biologicznych pozwolą na podjęcie decyzji operacyjnych korygujących proces, jak również jego optymalizację. W niniejszym artykule zaprezentowano możliwości wykorzystania analizy FTIR-DRIFT zawiesiny osadu czynnego połączonej z analizą chemometryczną wybranych parametrów osadu i ścieków do oceny procesu oczyszczania na poszczególnych etapach pracy reaktora biologicznego. Uzyskane wyniki wskazują, że zastosowanie techniki FTIR do szybkiej oceny procesu biologicznego jest możliwe, a w połączeniu z modelowaniem PLS i po odpowiednim skalibrowaniu z wartościami parametrów fizyczno-chemicznych może stanowić element kontrolny w eksploatacji oczyszczalni ścieków.

EN

The activated sludge process is the most popular method used in many sewage treatment plants, which usually allows to achieve the required ecological effect. However, it is also characterized by a certain instability of the obtained effects, depending on conditions and parameters which are partly beyond the operator's influence. Therefore, rapid analytical techniques are being sought for the control and assessment of activated sludge, which, in the event of irregularities occurring in biological tanks, will allow operational decisions to be made to correct the process as well as its optimization. This article presents the possibilities of using FTIR-DRIFT analysis of activated sludge suspension combined with chemometric analysis of selected sludge and sewage parameters to assess the course of the purification process at various stages of operation of the biological reactor. The obtained results indicate that the use of the FTIR technique for rapid assessment of a biological process is possible, and in combination with PLS modeling and after appropriate calibration with physical and chemical parameters, it can constitute a control element in the operation of sewage treatment plants.

6

Piaskowski Krzysztof

Gaz, Woda i Technika Sanitarna

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2024

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Nr 12

20--25

PL

Rosnące zapotrzebowanie na leki przeciwbólowe powoduje także wzrost obecności farmaceutyków w całym środowisku, stwarzając coraz większe zagrożenie. Jedną z głównych dróg rozpowszechniania się mikrozanieczyszczeń tego typu są ścieki, a jako pierwsze poddane wpływowi farmaceutyków są organizmy stanowiące biologiczną część oczyszczalni ścieków - osadu czynnego. W artykule przedstawiono badania nad wpływem trzech najpopularniejszych leków NLPZ zawierających ibuprofen, paracetamol oraz kwas acetylosalicylowy na aktywność osadu czynnego po 24 godz. kontaktu. Uzyskane wyniki wskazują na duże zróżnicowanie oddziaływania badanych leków. Ibuprofen wpływał na kłaczki osadu czynnego poprzez zwiększenie aglomeracji, podczas gdy paracetamol powodował ich defragmentację. Jednakże w obu przypadkach indeks osadu SVI zwiększał się nawet o 38%, podczas gdy dla kwasu acetylosalicylowego zmniejszał się o 20%. Natomiast aktywność osadu mierzona testem aktywności enzymu dehydrogenazy TTC zmniejszyła się o ponad 80% w próbkach z paracetamolem, dla kwasu acetylosalicylowego nieznacznie wzrastała, podczas gdy dla ibuprofenu, zwiększała się nawet dwukrotnie, co wskazuje, że wpływ na osad czynny może mieć nie tylko rodzaj substancji aktywnej, ale również obecne w lekach substancje pomocnicze.

EN

The increasing demand for pain medications is also increasing the presence of pharmaceuticals throughout the environment, posing an increasing threat. One of the main sources of the spread of this type of micropollutant is sewage, and the first to be affected by pharmaceuticals are organisms that constitute the biological part of the sewage treatment plant - activated sludge. The article presents research on the influence of the three most popular NSAIDs containing ibuprofen, paracetamol and acetylsalicylic acid on the activity of activated sludge after 24 hours. contact. The obtained results indicate a very large differentiation of the impact of the tested drugs. Ibuprofen affected the activated sludge flocs by increasing agglomeration, while paracetamol caused their defragmentation. However, in both cases the SVI sediment index increased by up to 38%, while for acetylsalicylic acid it decreased by 20%. The activity of activated sludge measured by the TTC dehydrogenase enzyme activity test decreased by more than 80% in samples with paracetamol, increased slightly for acetylsalicylic acid, while for ibuprofen it increased even twofold, which indicates that not only the type of active substance but also the excipients present in the drugs may have an influence on the activated sludge.

7

Analiza osadu czynnego ważnym narzędziem kontroli pracy biologicznych oczyszczalni ścieków

Bazeli Monika

Forum Eksploatatora

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2024

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Nr 1 (126)

35-37

PL

Proces osadu czynnego jest najpowszechniej stosowaną techniką oczyszczania ścieków na całym świecie.

8

Application of sludge-based adsorbent for Acid Red 18 adsorption

Pieczykolan Barbara

Architecture Civil Engineering Environment

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2024

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Vol. 17, no. 1

105--114

EN

A study was conducted on the use of excess activated sludge from a municipal wastewater treatment plant as an adsorbent in the removal of Acid Red 18. The excess sludge was thermally modified using microwave radiation. The study aimed to evaluate the possibility of using this type of waste adsorbent in the batch adsorption process to remove a selected synthetic dye. Moreover, the experiments were aimed at analyzing the adsorption kinetics and adsorption isotherms of the batch adsorption process. Experimental results showed that in the case of adsorption kinetics, a greater match with experimental results was obtained for the pseudo-second-order model. This indicates that the adsorption process was chemical in nature. In the case of adsorption isotherm analysis, it showed that the best fit to experimental results was obtained for the Langmuir, Sips, and Toth isotherm models. Thus, this indicates the occurrence of a single-layer adsorption process. The determined values of adsorption capacity based on the Langmuir, Sips, and Toth models are in the range of 71.6 mg/g-79.0 mg/g.

9

Automatic System for Acquisition and Analysis of Microscopic Digital Images Containing Activated Sludge

Staniszewski Michał, Dziadosz Marcin, Zaburko Jacek, Babko Roman, Łagód Grzegorz

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no. 7

51--61

EN

The article contains the procedure of image acquisition, including sampling of analyzed material as well as technical solutions of hardware and preprocessing used in research. A dataset of digital images containing identified objects were obtained with help of automated mechanical system for controlling the microscope table and used to train the YOLO models. The performance of YOLOv4 as well as YOLOv8 deep learning networks was compared on the basis of automatic image analysis. YOLO constitutes a one-stage object detection model, aiming to examine the analyzed image only once. By utilizing a single neural network, the image is divided into a grid of cells, and predictions are made for bounding boxes, as well as object class probabilities for each box. This approach allows real-time detection with minimal accuracy loss. The study involved ciliated protozoa Vorticella as a test object. These organisms are found both in natural water bodies and in treatment plants that employ the activated sludge method. As a result of its distinct appearance, high abundance and sedentary lifestyle, Vorticella are good subjects for detection tasks. To ensure that the training dataset is accurate, the images were manually labeled. The performance of the models was evaluated using such metrics as accuracy, precision, and recall. The final results show the differences in metrics characterizing the obtained outputs and progress in the software over subsequent versions of the YOLO algorithm.

10

The Influence of Abiotic Factors on Organisms-Hydrobionts of Activated Sludge

Baimukasheva Shynar, Issayeva Akmaral U., Antkowiak Wojciech, Aitimova Ainazhan, Altybayeva Zhansaule, Syrlybekkyzy Samal, Suleimenova Botagoz, Koishina Akmaral

Journal of Ecological Engineering

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2023

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Vol. 24, nr 10

125--133

EN

Rational use of water resources is one of the urgent problems for arid regions of Kazakhstan. The biocenosis of activated sludge of urban wastewater treatment plants in Zhanaozen periodically encounters stressful situations associated with violation of the operating mode of equipment or emergency discharges of toxicants into the wastewater treatment plant system. It has been established that with sharp fluctuations in the physicochemical parameters of aqueous solutions, protozoal organisms are primarily eliminated from the composition of activated sludge. This pattern was noted with an increase in the content of ammonium nitrogen, phosphorus, monoethanolamine and pH fluctuations in wastewater. Under the conditions of a 10-month period of active insolation in Western Kazakhstan, the species diversity of the algoflora of activated sludge correlates with the duration of daylight hours; it was found that diatoms predominate in the autumn-winter period of the year, whereas blue-green and green algae predominate in the spring-summer period.

11

Alternating Aerobic and Anoxic Conditions to Eliminate Sludge Accumulation in the Oxidation Ditch System

El-Morsy Ahmed, Ayoub Mohamed

Journal of Ecological Engineering

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2023

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Vol. 24, nr 3

304--314

EN

The purpose of the present study is to investigate the performance of an upgraded oxidation ditch (OD) system, which was designed and implemented to solve the problem of sludge accumulation at the bottom as well as to get the best removal efficiency of total nitrogen (TN). The upgrading concept is based on dividing the operating volume of the upgraded OD to achieve interchanging between aerobic and anoxic circumstances in order to provide simultaneous nitrification and denitrification (SND). The obtained results indicated that the average TN removal efficiency was 60%, which could be obtained due to a highly efficient SND approach. In addition, the better TN removal efficiency corresponds to the lower sludge volume index (SVI), which reflects the efficiency of the upgraded OD in preventing the accumulation of sludge at the bottom. Effluent ammonium-nitrogen (NH4+-N) and nitrate (NO3--N) concentrations corresponding to a minimum SVI of 41.9 mL/g were 8.6 mg/L for NH4+-N and 8.6 mg/L for NO3--N, respectively. Furthermore, the upgraded OD successfully removes 5-day biochemical oxygen demand (BOD5), chemical oxygen demand (COD), and total suspended solids (TSS) below the permissible limit for final effluent of 60, 80, and 50 mg/L respectively.

12

Treatment of Hospital Wastewater Using Activated Sludge with Extended Aeration

Custodio María, Cuadrado-Campó Walter, Peñaloza Richard, Vicuña-Orihuela Carmela, Torres-Gutiérrez Elmer, Orellana Edith

Journal of Ecological Engineering

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2022

|

Vol. 23, nr 11

24--32

EN

Hospital wastewater is of a complex nature and is generally discharged into urban sewage systems. This study evaluated the removal efficiency of organic and biological contaminants from a hospital wastewater treatment plant using extended aeration activated sludge. The study was conducted at a treatment plant scale, with 14 hours of feed. The plant consists of a pre-filter, a collector and crumbler tank, a homogenization tank, two biological reactors of 80 000 liters capacity each, two settlers and a contact disinfection chamber. Three flow rates of 3 L/s, 4 L/s and 5 L/s were tested in each biological reactor, with application of three concentrations of residual chlorine with sodium hypochlorite to the effluent of the settling tanks (0.3 ppm, 0.4 ppm and 0.5 ppm). The removal efficiency of suspended solids varied according to flow rate. The reactor with a flow rate of 3 L/s and 0.5 ppm of residual chlorine achieved the highest removal of suspended solids (91.95%), biological oxygen demand (97.52%) and fecal coliforms (99.99%). Finally, the quality of the hospital wastewater is within the limits of the national and international environmental quality thresholds.

13

Zastosowanie wolnoobrotowego systemu mieszania w sekwencyjnych bioreaktorach porcjowych z osadem czynnym

Zaburko Jacek, Szulżyk-Cieplak Joanna, Widomski Marcin K., Łagód Grzegorz

Gaz, Woda i Technika Sanitarna

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2022

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Nr 6

36--39

PL

Zaostrzające się wymogi, dotyczące jakości ścieków odprowadzanych do odbiornika, doprowadziły do opracowania wielu urządzeń wykorzystywanych podczas biologicznego oczyszczania. Obecne badania prowadzone w sektorze wodno-ściekowym skupiają się często na poszukiwaniu efektywnych energetycznie rozwiązań technicznych i technologicznych, wywierających jak najmniej negatywny wpływ na środowisko „przy jednoczesnym obniżeniu kosztów eksploatacyjnych. W systemach oczyszczania powszechnie wykorzystuje się właściwości struktur mikroorganizmów w postaci kłaczków osadu czynnego, które usuwają organiczne i biogenne związki zawarte w ściekach. Ważnym elementem powyższego rozwiązania jest zastosowanie układu mieszania i napowietrzania bioreaktorów w odpowiedniej konfiguracji. W oczyszczalni ścieków, z częścią biologiczną, działającej w technologii SBR, stosuje się wiele rodzajów urządzeń do mieszania. W niniejszym artykule przedstawiono zastosowanie innowacyjnego wolnoobrotowego systemu mieszania w sekwencyjnych bioreaktorach porcjowych, w których czynnikiem procesowym jest osad czynny.

EN

Increasing demands on the quality of wastewater discharged to the receiving water have led to the development of many biological treatment devices. Current research in the water and wastewater sector often focuses on finding energy-efficient solutions that have the least negative impact on the environment while reducing operating costs. In wastewater treatment systems, it is common to utilize the properties of microbial structures in the form of activated sludge flocs that remove organic compounds and biogenic contained in wastewater. An important part of the solution is the mixing and aeration system configuration used. In the treatment plant operating in the SBR technology, there are many types of mixing devices that are used in the process of wastewater treatment. This paper presents the application of an innovative slow-speed mixing system in sequential batch bioreactors in which activated sludge is a process factor.

14

Mikroorganizmy prowadzące biodegradację wielopierścieniowych węglowodorów aromatycznych w osadach czynnych i dennych

Paprocki Jakub

Gaz, Woda i Technika Sanitarna

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2022

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Nr 5

16--23

PL

W artykule omówiono metody wykorzystywane w biodegradacji wielopierścieniowych węglowodorów aromatycznych występujących w osadach czynnych i dennych. Przeanalizowano ich skuteczność i wpływ na oczyszczanie środowiska z zanieczyszczeń WWA.

EN

The article discusses the methods used in the biodegradation of polycyclic aromatic hydrocarbons found in active and bottom sediments. Their effectiveness and influence on the purification of the environment from PAH pollution were analyzed.

15

Optical naturalny produkt do optymalizacji biologicznego oczyszczania ścieków

Wal Monika, Nowak Michał

Forum Eksploatatora

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2022

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Nr 1 (118)

30-31

16

Kondycja osadu czynnego

Szmelcer Piotr

Forum Eksploatatora

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2022

|

Nr 1 (118)

44-45

PL

Oczyszczanie ścieków metodą osadu czynnego zastosowano po raz pierwszy na początku XX wieku. Od tego momentu, po wielu udoskonaleniach, metoda ta jest wykorzystywana, z powodzeniem, na całym świecie.

17

Microscopic Analysis of Activated Sludge in Industrial Textile Wastewater Treatment Plant

Paździor Katarzyna, Bilińska Lucyna

Autex Research Journal

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2022

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Vol. 22, no. 3

358--364

EN

The relationship between a quality of activated sludge microbiota and wastewater treatment plant (WWTP) operational stability has been defined in the past few decades. However, this dependence is not so clear in the case of industrial wastewater treatment. In this article, a very specific example of industrial textile wastewater treatment plant (ITWTP) is analyzed. Textile effluents are well known as highly contaminated wastewater containing many biodegradable compounds. Microscopic analysis included flocs morphology examination, attempts to evaluate the Sludge Biotic Index (SBI), and identification of dominant filamentous microorganisms. Routine operational control of ITWTP covered pH, temperature, redox potential, dissolved oxygen and COD measurements. The average ecosystem existing in the described ITWTP differed significantly compared to municipal WWTPs. The flocs were smaller and irregular. Filamentous bacteria did not cause foaming although filaments index reached 4. Nostocoida limicola I dominated with significant amounts of type 0041 and type 021N. The evaluation of SBI was impossible as the most of protozoan was in the form of cysts. The overall microbiota diversity correlated with COD removal in activated sludge unit of ITWTP.

18

Treatment of Wastewater with High Ammonium Nitrogen Concentration

Marek Kinga, Pawęska Katarzyna, Bawiec Aleksandra

Journal of Ecological Engineering

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2021

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Vol. 22, nr 4

224--231

EN

The paper deals with the problem of wastewater treatment with specific physicochemical composition (increased ammonium nitrogen concentration) which were generated in Motor Rest Areas (MRA). Conventional biological wastewater treatment systems with activated sludge were used to purify the wastewater from sanitary equipment used in MRA. On the basis of the research conducted on four MRA, an attempt was made to determine the impact of the wastewater quality on biological wastewater treatment processes. The wastewater supplied to the treatment system was characterized by predominance of biologically non-degradable organic matter (average BOD/ COD ratio 4.39 – 10.42) as well as high concentration of ammonium nitrogen 273.9 – 334.55 mgN-NH4/dm3. The wastewater alkalinity determined by high content of ammonium nitrogen had a negative impact on the biological treatment processes. Unequal pollution load and temporary, high hydraulic load caused leaching of solid suspension from settling tank as well as leaching of particles of activated sludge from the reactor’s chamber. The lack of organic matter susceptible to biological decomposition makes it difficult to develop the biocenosis of activated sludge, and the limits of ammonium nitrogen concentration inhibit the nitrification processes.

19

The Effect of Bioaugmentation Strategy on the SBR Performance Treating Reject Water and Municipal Wastewater Under Various Temperature Conditions

Szaja Aleksandra, Szulżyk-Cieplak Joanna

Journal of Ecological Engineering

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2021

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Vol. 22, nr 7

46--56

EN

In this study, the effect of bioaugmentation on the sequencing batch reactor (SBR) performance while treating municipal wastewater and reject water under various temperature conditions was examined. Two lab-scale SBRs, each with the active volume of 8 L were used to perform this research. For bioaugmentation, a mixture of wildliving Bacteria and Archaea in a dose 0.25 mL was added to SBR A, while SBR B was a control one. Both reactors were fed with a mixture of wastewater and 13% v/v reject water. During the experiment, 5 phases with different temperature range were distinguished, each one lasted 14 d. The temperatures were investigated in 5°C increments, i.e. 20, 25, 30, 25 and 20°C. The obtained results indicated that in the bioaugmented reactor (SBR A), lower concentrations of NH4+–N, TSS, NO2-–N in effluent were observed as compared to control (SBR B). While for NH4+–N, regardless the temperature, the observed differences were statistically significant. Importantly, in both SBRs, the process was carried out in a stable way.

20

Study of Physicochemical and Bacteriological Quality of Treated Wastewater by the New Aourir Plant (Southwestern of Morocco) Using Activated Sludge Technology in a Semi-Arid Region

Hajji Sara, Ait Alla Aicha, Noureddine Slimani, Haddad Mohamed Ben, Moukrim Abdellatif

Journal of Ecological Engineering

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2021

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Vol. 22, nr 6

83--98

EN

In order to use the purified wastewater for the irrigation of a golf course in the Taghazout area (Southwestern of Morocco), this study was conducted to evaluate the physicochemical and bacteriological quality of the treated wastewater in the new Aourir plant (Activated Sludge technology). In order to achieve these objectives, three types of water were analyzed: raw water (RW), biologically treated water (BTW) and water treated by ultraviolet radiation (UV-TW). The physicochemical parameters analyzed were Temperature, pH, Electrical Conductivity (EC), Dissolved Oxygen (DO), Chemical Oxygen Demand (COD), five-day Biological Oxygen Demand (BOD5), Total Suspended Solids (SS), Nitrate (NO3), and Orthophosphates (PO4). Otherwise, the analyzed biological parameters are Total Coliforms (TC), Fecal Coliforms (FC), Escherichia coli (E. coli), and Fecal Streptococci (FS). The physicochemical parameters showed that temperature is always lower than 30°C, the pH is close to neutrality and a strong fluctuation of the high electrical conductivity (2700 μS/cm) occurs in UV-TW. At all stages of wastewater treatment, COD, BOD5, SS, NO3 and PO4 were below the limit values recommended by Moroccan standards. The bacteriological results showed a high level of bacterial contamination in RW and BTW, but in UV-TW the loads did not exceed 3 log10. The average loads of TC, FC, E. coli and FC in UV-TW were 2.13, 1.67, 1.77, and 2 (log10 CFU/100ml) respectively. Activated sludge treatment combined with UV has demonstrated sufficient quality to reuse treated water in irrigation; however, the UV treatment requires control to avoid any effect on the microbiological and physicochemical quality of green spaces and groundwater.