Baigiamajame magistriniame darbe tirta Utenos nuotekų valymo įrenginių pirminio ir perteklinio veikliojo dumblo mišinio skirtingų polimerų ir geležies druskų anaerobiniam puvimo procesui įtaka. Analizėje nagrinėjama proceso metu išsiskiriančių biodujų tūris ir metano dujų koncentracija. Tyrime naudojamas anaerobinio pūdymo modelis „W8 Armfield Ltd“, kuris dirba kaip vienalaipsniai anaerobiniai reaktoriai su mezofiliniu režimu. Išbuvimo trukmė – 20 dienų, apkrova bepelenėmis sausomis medžiagomis (BSM) nuo 0,61–0,96 gBSM/l/d, tiekiamo dumblo mišinio sausų medžiagų kiekis (SM) – 4 %. Baigiamuoju darbu siekiama išanalizuoti dumblo tirštinimui naudojamo sintetinio arba natūralaus polimero ir dozuojamos druskos (geležies sulfato (Fe2(SO4)3) bei geležies chlorido (FeCl3)) įtaką anaerobiniam pūdymo procesui. Panaudojus anaerobinio pūdymo modelį buvo sukurtos anaerobinės sąlygos ir pūdomas iš Utenos nuotekų valyklos tiekiamas pirminio ir perteklinio dumblo mišinys. Naudojantis įrenginiu INCA 4000 T100 buvo kaupiamos biodujos ir analizuojama jų sudėtis. Darbe taip pat nagrinėjamas SM sumažėjimas ir BSM suskaidymas. Įvertinus visus analizuojamus kriterijus nustatomas efektyviausias metodas išsiskiriančių dujų efektyvumui ir kokybei pagerinti. Išanalizavus tyrimo rezultatus pateiktos išvados. Darbą sudaro šios dalys: įvadas, 4 skyriai, išvados, rekomendacijos, literatūros sąrašas. Darbo apimtis – 63 p. teksto be priedų, 32 paveikslai, 8 lentelės, 42 bibliografiniai šaltiniai. / Objective of this work was to investigate impact of different iron and polymer doses on anaerobic digestion process. Primary and waste activated sludge was obtained from Utena Wastewater treatment plant. Analysis shows the volume of biogas produced and percentage of methane. The work was carried out using high-rate anaerobic digestion model W8 (Armfied Ltd. UK) which operates in the mesophilic range. The solids retention time was 20 days. The volatile suspended solids loading rate ranged from 0.61 to 0.96 g VSS/l d.Sludge mixture feed concentration – 4%. The Purpose of this work is to analyse impact of synthetic and organic polymer also iron (III) sulphate (Fe2(SO4)3) and iron (III) chloride (FeCl3) on anaerobic digestion process. Primary and waste activated sludge was obtained from Utena Wastewater treatment plant. The biogas was collected and components were analysed using INCA 4000 T100 analyser. Analysis of TS reduction and VS destruction is also presented. The most effective method of improving off-gas efficiency and quality was determined considering all the criteria determined by analysis. Having analyzed the results of the research, conclusions have been made. This work consists of the following parts: pre-face, 3 sections, conculsions, recommendations, reference list. There are 63 pages of text without appendices, 32 figures, 8 tables and 42 bibliographical sources in this work.

Bioflocculation, which can be defined as aggregation of bacterial flocs, has important implications on the physical characteristics of sludge. It is especially critical to settling and dewatering systems which impacts the overall economy of the process greatly. One of the most common problems in activated sludge systems to negatively influence the settleability is sludge bulking which can be defined as non-settling situation of microbial mass. The first objective of this research is to investigate the effect of calcium ion on sludge bulking in a phosphorus deficient medium and the second objective is to improve the settling, dewatering, and pumping of activated sludge by adjusting the calcium (Ca) ion concentration of the feed. For this purpose, 7 semi-continuous laboratory scale activated sludge reactors were operated with a mixed aerobic culture. The reactors had 8 days of sludge residence time and aerated with air pumps to provide a dissolved oxygen concentration of at least 3 mg/L. All the analyses were conducted after the reactors reached steady state condition. In the first part of the research, the effect of strictly phosphorus-limited medium on bulking of activated sludge was studied at different calcium ion concentration. Three reactors were set up having 5, 10 and 20 meq/L calcium concentrations. From the results it was observed that, phosphorus deficiency caused viscous bulking independent from the calcium ion concentration. It was found out that bulking of activated sludges due to phosphorus deficiency could be cured by the addition of phosphorus. Furhermore, microorganisms starved for phosphorus, seemed to accumulate polyphosphate granules when they were exposed to a phosphorus source. In the second part of the study, the effect of calcium ion on physical, chemical and surface chemical properties of activated sludge was investigated at 4 different concentrations (0.27, 5, 10 and 20 meq/L) under sufficient phosphorus concentration. Calcium addition resulted in significant changes in the quantity and quality of extracellular polymeric substances (EPS). Total EPS increased depending on the calcium concentration. Carbohydrate content of EPS dominated over the protein content for calcium concentration of 5 meq/L and above. The amount of calcium ions incorporated into the sludge floc matrix also increased with the dose of calcium added. Settleability and dewaterability of sludge improved significantly at 5 meq/L dose of calcium. However, settleability did not change any further with increasing calcium dose, whereas dewaterability increased for all increasing calcium concentrations. Sludge viscosity also decreased considerably at 5 meq/L concentration indicating better pumpability but it did not change further above 10 meq/L calcium addition.

Activated sludge systems are the most widely used biological wastewater treatment processes all over the world. The main working principles of an activated sludge system are the oxidation of biologically degradable wastes by microorganisms and the subsequent separation of the newly formed biomass from the treated effluent. Separation by settling is the most troublesome stage of an activated sludge process. A decrease in the efficiency of the separation of microbial biomass from the treated effluent causes a decrease in the overall efficiency of the treatment plant. The efficiency of the separation process is related to the bioflocculation, which can be briefly defined as the aggregation of the bacteria into flocs through flocculation. Bioflocculation depends on the extracellular polymers (EPS) that are produced by microorganisms. The operating conditions of the activated sludge system is a key determinant of the synthesis of EPS and bioflocculation. The main objective of this study is to find out the effect of magnesium ions on the bioflocculation process under phosphorus deficient and sufficient conditions. In order to achieve this aim, the effects of magnesium ion in 4 different concentrations (0.9, 5, 10 and 20 meq/L) are investigated in semi continuous reactors. The reactors are operated at a mean cell residence time of 8 days and 20&ordm / C temperature. When reactors are confirmed to be at steady state, several sets of analysis are conducted. In particular, the surface chemical parameters including EPS and its components, electrical charge, and hydrophobicity as well as physical properties such as settlability, filterability, viscosity, floc strength, and turbidity are examined. It has been understood that phosphorus deficiency causes severe filamentous bulking under magnesium rich conditions. Increasing the phosphorus concentration in the influent can cure this problem. After the sludges are cured some granular structures were observed in the microscopic investigations and they are thought to be polyphosphate granules in which microorganisms tend to accumulate phosphorus when they find the adequate source after a starvation period. To consider the reactors operated at phosphate present conditions, it has been found that EPS increases with increasing influent magnesium concentration. However, protein type EPS (EPSP) exhibits a sharper increase when compared to the carbohydrate type EPS (EPSC) indicating the selective attitude of magnesium ions to protein type of polymers. It has been understood that the increase in the influent magnesium concentration results in an increase in dewaterability and zone settling velocity, and a decrease in the viscosity. Hydrophobicity was found to exhibit a maximum value at 10 meq/L magnesium fed sludge and then it dropped back. Surface charge values also made a minimum at 10 meq/L reactor and then no change occurred at the increase of the magnesium concentration to 20 meq/L. Finally, COD values were found to increase with the increasing magnesium concentration due to the increasing EPS.

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High nitrogen discharge from the municipal wastewater is a major concern for the South Australian Government, primarily due to negative impacts on the marine environment. Therefore, under the South Australian Environmental Improvement Program, (SA EIP), all metropolitan wastewater treatment plants have been reconfigured to achieve enhanced nitrogen removal. Secondary treatment (denitrification process) at the metropolitan wastewater treatment plants must be optimised to meet the discharge guideline of 10 mg/L total nitrogen. However, secondary treatment at some plants is carbon limited (low C/N ratio), and external carbon supplementation is required to meet this discharge guideline. Molasses provides the current external carbon source at two plants. It is relatively inexpensive, but other carbon sources, particularly industrial waste streams, may be more attractive, due to the potentially lower material cost, as it is practically free, and environmentally friendly. Potato starch and sonicated return activated sludge (RAS) were considered. In this study, the bioavailability of the soluble carbon in potato starch and ultrasound treated RAS were assessed. The associated objective was to investigate the potential of both carbon sources as an external carbon donor for the denitrification zone of wastewater treatment plants to economically improve biological nitrogen removal. The economic analysis was performed using mainly United States dollars and the fixed capital investments and total capital costs were converted to Australian dollars. This was due to the United States dollars currency quotes obtained for the materials and unit operations required. SCOD from the three sources was quantified and preliminary results were presented. Molasses provided the highest SCOD release of 1.1285 x 10⁶ mg-SCOD/L, sonicated RAS produced 5.6 to 68.4 times the SCOD release of the untreated RAS (35.6 mg-SCOD/L) depending on the ultrasound intensity and treatment time, while the highest soluble carbon release obtained using potato starch was 809 mg-SCOD/L (using 20.9 g/100 mL potato starch concentration). Based on the experimental SCOD results, batch denitrification tests using the proposed carbon sources were carried out. The nitrogen removal efficiency at low dose (12.48 mg-SCOD/L) using molasses, potato starch and sonicated RAS were 77.54%, 57.24%, and 72.76% respectively, whilst at high dose (124.80 mg-SCOD/L) were 94.04%, 66.32%, and 92.10% correspondingly. In similar order of the proposed carbon sources, the nitrate removal rates for the first phase denitrification with low dose were 1.44, 1.16, and 1.18 mg-NO₃ − /h respectively, whilst the nitrate removal rate of the first phase denitrification with high dose improved to 2.01, 1.26, and 1.96 mg-NO₃ −/h correspondingly. From the denitrification test results, molasses proved to be the optimal carbon source in terms of nitrate removal. However sonicated RAS possesses similar denitrification performance and may be a suitable alternative. An economic analysis for sonicated RAS Option 2 confirmed it as the most viable substitute. The time to recover the initial investment (payback period) is approximately 6.5 years and the breakeven point is approximately 8 years. Both denitrification tests and economic analyses demonstrate that sonicated RAS may be a viable and attractive substitute for the molasses. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1337059 / Thesis (M.Eng.Sc.) - University of Adelaide, School of Chemical Engineering, 2008

High nitrogen discharge from the municipal wastewater is a major concern for the South Australian Government, primarily due to negative impacts on the marine environment. Therefore, under the South Australian Environmental Improvement Program, (SA EIP), all metropolitan wastewater treatment plants have been reconfigured to achieve enhanced nitrogen removal. Secondary treatment (denitrification process) at the metropolitan wastewater treatment plants must be optimised to meet the discharge guideline of 10 mg/L total nitrogen. However, secondary treatment at some plants is carbon limited (low C/N ratio), and external carbon supplementation is required to meet this discharge guideline. Molasses provides the current external carbon source at two plants. It is relatively inexpensive, but other carbon sources, particularly industrial waste streams, may be more attractive, due to the potentially lower material cost, as it is practically free, and environmentally friendly. Potato starch and sonicated return activated sludge (RAS) were considered. In this study, the bioavailability of the soluble carbon in potato starch and ultrasound treated RAS were assessed. The associated objective was to investigate the potential of both carbon sources as an external carbon donor for the denitrification zone of wastewater treatment plants to economically improve biological nitrogen removal. The economic analysis was performed using mainly United States dollars and the fixed capital investments and total capital costs were converted to Australian dollars. This was due to the United States dollars currency quotes obtained for the materials and unit operations required. SCOD from the three sources was quantified and preliminary results were presented. Molasses provided the highest SCOD release of 1.1285 x 10⁶ mg-SCOD/L, sonicated RAS produced 5.6 to 68.4 times the SCOD release of the untreated RAS (35.6 mg-SCOD/L) depending on the ultrasound intensity and treatment time, while the highest soluble carbon release obtained using potato starch was 809 mg-SCOD/L (using 20.9 g/100 mL potato starch concentration). Based on the experimental SCOD results, batch denitrification tests using the proposed carbon sources were carried out. The nitrogen removal efficiency at low dose (12.48 mg-SCOD/L) using molasses, potato starch and sonicated RAS were 77.54%, 57.24%, and 72.76% respectively, whilst at high dose (124.80 mg-SCOD/L) were 94.04%, 66.32%, and 92.10% correspondingly. In similar order of the proposed carbon sources, the nitrate removal rates for the first phase denitrification with low dose were 1.44, 1.16, and 1.18 mg-NO₃ − /h respectively, whilst the nitrate removal rate of the first phase denitrification with high dose improved to 2.01, 1.26, and 1.96 mg-NO₃ −/h correspondingly. From the denitrification test results, molasses proved to be the optimal carbon source in terms of nitrate removal. However sonicated RAS possesses similar denitrification performance and may be a suitable alternative. An economic analysis for sonicated RAS Option 2 confirmed it as the most viable substitute. The time to recover the initial investment (payback period) is approximately 6.5 years and the breakeven point is approximately 8 years. Both denitrification tests and economic analyses demonstrate that sonicated RAS may be a viable and attractive substitute for the molasses. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1337059 / Thesis (M.Eng.Sc.) - University of Adelaide, School of Chemical Engineering, 2008

Οι Μεσογειακές χώρες ετησίως, κατά την παραγωγή του ελαιολάδου, έρχονται αντιμέτωπες με τη διαχείριση των υγρών αποβλήτων των ελαιοτριβείων, τα οποία περιέχουν μεγάλες ποσότητες οργανικών ουσιών και αιωρούμενων στερεών, προερχόμενα από τον καρπό και το χρησιμοποιούμενο νερό κατά τη μεταποιητική διαδικασία. Η απόρριψή τους στο περιβάλλον ρυπαίνει υδροφόρους ορίζοντες και επιφανειακά ύδατα, υποβαθμίζει το έδαφος, προκαλεί τοξικότητα και δυσάρεστη οσμή. Πλήθος φυσικοχημικών, αλλά και βιολογικών μεθόδων έχουν δοκιμασθεί στην προσπάθεια εξάλειψης των δυσμενών τους χαρακτηριστικών, χωρίς να έχουν δώσει σε ευρεία κλίμακα λύση, προσκρούοντας κυρίως σε προβλήματα κόστους εγκατάστασης και λειτουργίας καθώς και στη διακύμανση της σύστασης τους. Στόχος της παρούσας έρευνας είναι η μελέτη της συμπεριφοράς των υγρών ελαιουργικών λυμάτων κατά τη διοχέτευση τους σε μονάδα επεξεργασίας αστικών λυμάτων, ώστε να είναι δυνατή η συνεπεξεργασία των δύο αυτών διαφορετικών ειδών λυμάτων και να διερευνηθεί η δυνατότητα χρήσης ενός αντιδραστήρα ενεργού ιλύος με προσροφητικό υλικό, PVA-gels Biocarriers. Δημιουργήθηκαν 6 αντιδραστήρες με συγκεκριμένες αραιώσεις κατσίγαρου προς αστικά λύματα, σε συγκεντρώσεις ½, 1/10 και 1/100. Στο υπερκείμενο των συνθετικών λυμάτων πραγματοποιούνταν μετρήσεις των φυσικοχημικών χαρακτηριστικών του ανεπεξέργαστου και επεξεργασμένου συνθετικού λύματος περιοδικά έως το τέλος της πειραματικής διαδικασίας (16/1/2011). Επίσης εξετάστηκε η μικροβιακή χλωρίδα του επεξεργασμένου συνθετικού λύματος και η αποκατάστασή της. Παρατηρήθηκε ότι όλα τα συστήματα επεξεργάζονταν ικανοποιητικά απόβλητα που περιείχαν ελαιουργικά λύματα σε αναλογία 1/100 κατ’ όγκο, ότι η μικροβιακή τους χλωρίδα αποκαθίσταται, και θα μπορούσαν να διατεθούν σε φυσικό αποδέκτη, ικανοποιώντας τα περισσότερα κριτήρια της οδηγίας 91/271/ΕΕC. Στα συστήματα με αναλογία ½ και 1/10 κατ’ όγκο, παρατηρήθηκε αξιόλογη επεξεργασία σε κάποιες παραμέτρους αλλά και πάλι ήταν υψηλότερη από τα όρια διάθεσης. Τέλος, δεν παρατηρήθηκε κάποια αξιόλογη διαφοροποίηση μεταξύ των δύο συστημάτων ενεργού ιλύος με και χωρίς Biocarriers, τουλάχιστον για αυτό το πρώτο στάδιο εισαγωγής των Biocarriers. / Every year Mediterranean countries face the same problem of the olive oil mill wastewater management. This type of wastewater contains high concentration of organic loads and particulate suspended matter originating from the olives and the production water. Dumping this kind of wastewater untreated to the environment pollutes both surface and groundwater, degrades the soil quality and creates toxic environments and unpleasant odors. Several physicochemical as well as biological methods have been tested unsuccessfully due to the construction and operational costs as well as the variability of the wastewater characteristics. The goal of the present research is to study the behavior of the olive oil mill wastewater while it is introduced in a municipal wastewater treatment plant. The use of PVA-gels as Biocarriers in such a system is also tested. Six bioreactors were used with constant ratios of olive oil mill wastewater to municipal wastewater equal to ½, 1/10, and 1/100. The physicochemical parameters of the supernatant were measured periodically till the end of the experiment (16/1/2011). In addition the microbial communities of the different reactors were monitored especially after the return to the normal operation with municipal wastewater. Both systems treat the olive oil mill wastewater mixed with municipal wastewater in a ratio of 1/100 satisfactorily with outflow that could be discarded to natural receiver being close to the requirements set by the European directive 91/271/ΕΕC. Also, after the return to the normal operation with municipal wastewater the microbial community was easily restored. In systems with such ratios equal to ½ and 1/10, the treatment is effective but the outflow is high over the limits set for municipal wastewater treatment plants. Finally, no significant deviation was observed for activated sludge systems with and without Biocarriers for this initial stage of Biocarriers introduction.

Submitted by Lucienne Costa (lucienneferreira@ufcg.edu.br) on 2018-09-13T17:38:25Z No. of bitstreams: 1 LAIO ARIEL LEITE DE PAIVA – DISSERTAÇÃO (PPGECA) 2016.pdf: 2279883 bytes, checksum: ddf555f3b9251dc01dc78d5b5fe5df71 (MD5) / Made available in DSpace on 2018-09-13T17:38:25Z (GMT). No. of bitstreams: 1 LAIO ARIEL LEITE DE PAIVA – DISSERTAÇÃO (PPGECA) 2016.pdf: 2279883 bytes, checksum: ddf555f3b9251dc01dc78d5b5fe5df71 (MD5) Previous issue date: 2016-02-29 / Capes / Sistemas anaeróbios modernos de tratamento de esgoto doméstico, embora bastante eficientes na remoção de matéria orgânica e sólidos em suspensão, não produzem um efluente com qualidade compatível com os padrões legais para descarga em corpos d’água receptores. Por essa razão esses sistemas têm que ser associados a unidades de pós-tratamento. Este trabalho trata de uma investigação experimental sobre a viabilidade de se aplicar o sistema de lodo ativado como uma alternativa do pós-tratamento, especificamente para o caso em que se prevê o efluente final para reúso. Na investigação experimental se usou um reator de bateladas sequenciais (RBS) em escala de bancada como unidade de pós-tratamento. Os resultados experimentais mostraram que a qualidade de efluente do sistema RBS de pós-tratamento em relação a matéria orgânica é muito boa. Na otimização do reator RBS se desenvolveu um modelo que permite estabelecer o tempo de permanência mínimo para o pós-tratamento em função de dois parâmetros básicos: a constante de utilização de material orgânico biodegradável pelas bactérias heterotróficas do lodo gerado no sistema de pós-tratamento e a sedimentabilidade deste lodo. A constante de utilização de material orgânico foi determinada por testes respirométrico. O lodo gerado no sistema de pós-tratamento surpreendentemente mostrou ter uma sedimentabilidade bem superior àquela normalmente encontrada em sistemas de lodo ativado tratando esgoto bruto, o que constitui um argumento sólido para a aplicação do sistema RBS na prática de pós tratamento do efluente do reator UASB. / Modern anaerobic systems for domestic sewage treatment, although very effective in removing organic matter and solid suspended, do not produce an effluent quality compatible with the legal standards for discharge into water bodies’ receivers. Therefore, such systems have to be associated with post treatment units. This paper deals with an experimental investigation into the feasibility of applying the activated sludge system as an alternative post-treatment, specifically for the case where intended use of the treated wastewater is reuse. In the experimental investigation research, a sequencing batch reactor (RBS) at bench scale was use as post treatment. The experimental results showed that the effluent quality of the RBS post treatment system in relation to organic matter was very good. An algorithm to optimize the RBS reactor was developed and allowed establishing the minimum residence time for the post-treatment in terms of two basic parameters: the utilization constant of biodegradable organic material by heterotrophic bacteria in the post-treatment system and the sludge settleability. The organic material using respirometric constant was determined from the oxygen uptake rate during the post treatment. The sludge from the post-treatment system surprisingly showed a much better settleability than what normally found in activated sludge systems treating raw sewage, which provides a strong argument for the application of the RBS system in practice post-treatment of the UASB reactor effluent.