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Assessment of waters with complex contamination : Effect-based methods for evaluating wastewater treatment requirements and efficiencyRibé, Veronica January 2012 (has links)
The access to clean water is one of the prerequisites for a modern, industrialized society. The amount of water withdrawn for human activities has risen exponentially during the last 100 years. This rise in water use is accompanied by the production of vast quantities of contaminated water. These wastewaters may be contaminated by substances ranging from heavy metals and organic compounds to nutrients like nitrogen and phosphorous. The aggregate effect of combinations of water contaminants can be difficult to predict as different contaminant substances may interact, leading to additive, synergistic or antagonistic toxic effects in a receiving aquatic ecosystem. With increasing water quality legislation, the pressure to characterize and potentially treat contaminated waters increases. Suitable effect-based assessment methods may greatly reduce the costs of both the wastewater characterization process and the water treatment evaluation. The overall aim of this thesis was to show how a combination of ecotoxicity bioassays may be employed in water treatment method development for initial characterization, assessment of treatment requirements and finally treatment evaluation. The wastewaters characterized originated from different activities such as waste management, metal surfacing and explosives destruction. To fully assess the hazard of the waters sampled, a holistic approach using a combination of chemical tests and bioassays was taken. A combination of acute and chronic assays was used to determine mode-of-action effects and apical endpoints in the aquatic environment. The basic battery consisted of the acute Vibrio fischeri test, the chronic algae test using Pseudokirchneriella subcapitata and either the planktonic crustacean Daphnia magna (for aqueous samples) or the meiobenthic crustacean Heterocypris incongruens (for whole-sediment/soil samples). In addition to the basic test battery, the mode-of-action Salmonella typhimurium test was used to assess genotoxic effects. Results from the water hazard characterization show that ecotoxicological tests contribute to the evaluation of treatment methods for complex wastewaters by assessing the aggregate biological effect of water treatment. The tests may be used as a screening method to indicate where further treatment may be required, even when chemical measurements show a satisfactory reduction of known contaminants. The toxic effect exerted by the assessed waters did not always correlate with measured levels of contaminants or the chemical measures of bioavailability, e.g. leached fraction. The water treatment evaluation showed that the industrial by-product pine bark is an effective adsorbent for capturing metal contaminants from landfill leachates and stormwater. The pine bark column filter had higher zinc removal efficiency than the polonite filter and the combination filter column with pine bark/polonite. In conclusion, a pine bark filter is a suitable alternative to activated carbon for small-scale, decentralized treatment of wastewaters. Furthermore, the ecotoxicity tests were able to detect effects of unknown contaminants and provided unique characterization data, which complemented the information provided by the chemical analyses. / CLEAN / BIOREX
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Wood Drying Condensate Treatment Using a Bio – Trickling Filter with Bark Chips as a Support MediumKristiono, Arie January 2009 (has links)
The kiln drying of wood produces huge amounts of vapour. The vapour is released to the environment when the process purges some of the saturated hot air. The main environmental issue regarding the use of kiln drying process are the release of the water vapour which contains organic contaminants. Some of them are hazardous to human health. In addition, there are some wood particles which may released with the water vapour purging process.
In this research, the vapour is condensed and analysed for its organic contaminants and their biodegradability. The result showed that the dominant contaminants present in the condensate were ethanol and methanol with the concentration of approximately 65 mg/L and 25 mg/L respectively. The average COD concentration of the condensate was 159 ± 40 mg/L. The analysis also showed that the contaminants were biodegradable.
In order to treat the wastewater, a trickling filter process using bark chips as a support medium was used to treat an artificial wastewater. The artificial wastewater contained the dominant contaminant present in the wood drying condensate. In the experiment, different sizes of bark chips were used. In addition, the loading rate of the treatment system was varied by changing the flow rate and contaminant concentration.
The 30 cm long trickling filter using bark chips varying between of 2.8 – 4 mm diameter as the support medium gave a maximum removal of 36.4 % with removal capacity of 8.34 kg COD/m³bed•day at a flow rate of 2.8 cm/min and average inlet COD load of 20.4 kg COD/m3bed•day. The trickling filter with bark chips varying between 5.6 – 8 mm diameter as the support medium was operated using variations in contaminant concentration and flow rate. The operation using different inlet concentration gave the highest removal rate of 13.5 kg COD/m3bed•day at average initial load of 84.9 kg COD/m³bed•day, flow rate of 2.8 cm/min and theoretical initial concentration of 680 mg/L. The trickling filter operated with flow rate variation showed the highest removal rate of 10 kg COD/m³bed•day at an average inlet load of 53.3 kg COD/m³bed•day and flow rate of 7.1 cm/min.
The removal rate of the contaminants in treatment was limited. There is a number of possible explanations. First is the active surface area, which indicating the area where the contact between the biofilm surface and feed happened. The active surface area increased as the flow rate increased. Second is the residence time of the feed in the bed. The residence time of the feed varied with the flow rate. It decreased as the flow rate increased. Third is the influence of the contaminants in the feed. The presence of methanol and methanol in the feed inhibited each other’s degradation.
The dimention of a full-scale biotrickling filter to be used in actual kiln was also estimated. The estimation was made based on the maximum removal rate and optimum flow rate obtained in the experiments. The result of the estimation showed to obtain significant removal, the required bed would have to be 2.35 m in diameter and 160 in height.
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Fate Modeling of Xenobiotic Organic Compounds (XOCs) in Wastewater Treatment PlantsGhalajkhani, Rosita 04 November 2013 (has links)
Xenobiotic Organic Compounds (XOCs) are present in wastewater and wastewater-impacted environmental systems. Pharmaceuticals and personal care products are a broad and varied category of chemicals that are included among these compounds. Although, these compounds have been detected at low levels in surface water, concerns that these compounds may have an impact on human health and aquatic life, have led to increased interest in how XOCs are removed during wastewater treatment. Recognizing specific mechanisms in recent literature and simulating those mechanisms responsible for the removal of XOCs is the main objective of this study. Conventional models, such as the popular activated sludge models (ASM1, ASM2, etc), do not sufficiently address the removal processes; therefore, a fate model is created to provide a means of predicting and simulating removal mechanisms along with experimental analyses.
GPS-X is a multi-purpose modeling tool for the simulation of municipal and industrial wastewater treatment plants. This software package includes conventional models as built-in libraries, which can be used as bases on which new models can be created. In this thesis, the removal mechanisms of XOCs are recognized and investigated; a new library for GPS-X is also created to include XOCs.
As a first step the uncalibrated fate model, which includes all mechanisms of interest with their process rates and state variables, is developed using in GPS-X software. A modified ASM1 (Mantis model) is used as a basis for developing the fate model. Since only a group of mechanisms is responsible for the removal of each compound the mechanisms are categorized in three different case studies as the next step. Thus, one submodel is associated with each case study. The model developer toolbar in GPS-X software is used to develop the model for these case studies. The first case study involves the removal of antibiotics, such as Sulfamethoxazole. The removal mechanisms used in this case are biodegradation, sorption, and parent compound formation, with co-metabolism and competitive inhibition effects being inserted into the structure of the model. Secondly, the removal of nonylphenol ethoxylates (NPEOs) occurs through abiotic oxidative cleavage, hydrolysis, and biodegradation. The third case study includes removal mechanisms of biodegradation and sorption for neutral and ionized compounds.
In the calibration process, model parameters are tuned such that the model can best simulate the experimental data using optimization methods. A common error criterion is Sum of Squared Errors (SSE) between the simulated results and the measured data. By minimizing SSE, optimal values of parameters of interest can be estimated. In each case study different data sets were used for the validation process.
To validate the calibrated model, simulated results are compared against experimental data in each case study. The experimental data set used in the validation process is different from that used for calibrating the model, which means the validation process data set was obtained from the different literature. By looking at the validation results, it is concluded that the proposed model successfully simulates removal of XOCs.
Since the operating parameters of wastewater treatment plants, such as Solids Retention Time (SRT) and Hydraulic Retention Time (HRT) are crucial for the fate of XOC???s, a sensitivity analysis is carried out to investigate the effect of those parameters. Moreover, the pH effect is studied because it relates to the ionized XOCs. Sensitivity analysis results show that the fate model is more sensitive to model parameters i.e. biodegradation rate constant (kb) than the operational parameters, i.e. SRT and HRT. Furthermore, the responses showed sensitivity to pH, whereby acidic conditions provide a better environment for removing neutral forms and alkaline conditions were suitable for removing ionized forms, according to the ionized compound fate model.
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Fate of Select Pharmaceutically Active Compounds in the Integrated Fixed Film Activated Sludge ProcessMurray, Kyle January 2014 (has links)
Based on a diverse consortia of research completed within the last 15 years, it has been found that Pharmaceutical Compounds (PCs) are present in detectable levels within a variety of environmental matrices, including tap water. This is largely attributed to anthropogenic activities as humans are the majority consumer of PCs. As a result, the primary method of disposal is via wastewater pathways resulting from human excretion of ingested PCs. Based on past research into PC fate via the wastewater treatment process, only limited biotic and abiotic transformations are achieved – most PC’s are detected in the effluents of WWTP’s. This suggests that improving the removal of PCs during the wastewater treatment process provides a promising strategy for limiting the conveyance of PCs to the environment.
Historically, studies regarding PC fate in WWTPs have predominantly focused on the activated sludge process. However, fixed film (biofilm) wastewater treatment technologies continue to gain popularity at full scale wastewater treatment facilities. The limited studies which investigated fixed film wastewater treatment processes have reported that improved transformation efficiencies were observed relative to activated sludge systems. Based on these previous studies, it was postulated that the more diverse bacterial consortium present within the Integrated Fixed Film Activated Sludge (IFAS) process, a novel treatment process which has recently gained popularity in North America, may lead to improved transformation efficiencies (“removals”) of these very complex compounds. Only one previous study which investigated the transformation efficiencies of the IFAS process compared to a control was found. It was therefore considered that an additional investigation into the IFAS process warrants further investigation.
Four IFAS Sequencing Batch Biofilm Reactors (SBBRs) and four control Sequencing Batch Reactors (SBRs) were operated with varied experimental conditions in a 22 factorial design to investigate whether an observable difference in the level of PC transformations would result via the IFAS process when compared to a control. Experimental conditions were characterized by varying the operating Solids Retention Time (SRT) and mixed liquor temperature. For all other operational parameters, best efforts were made to ensure both reactors were operated under equivalent conditions. This permitted a true assessment of the effects of the inclusion of IFAS media.
Reactors were investigated through three phases of sampling, under which the performance of the reactors was investigated through the measurement of the following parameters:
• Conventional parameters (tCOD, sCOD, TAN, NO3-N) within the initial and final samples;
• Operational parameters (MLSS, MLVSS, ESS); and
• The transformation efficiencies achieved for 5 PC (Carbamazepine, Sulfamethoxazole, Trimethoprim, Atenolol and Acetaminophen).
During all three phases of PC sampling, the pilot reactors were found to have been performing as anticipated with respect to conventional contaminant removals. Organic removals were found to be statistically similar between the IFAS and control reactors across all four experimental conditions. Full nitrification was observed for all reactors with the exception of the control SBR operated under the low SRT, low temperature condition. The IFAS SBBRs were found to demonstrate improved nitrification kinetics when compared to their respective controls operated under the same experimental conditions. This was believed to be related to the more diverse bacterial consortia present as a result of the IFAS biofilms. All reactors were generally believed to be operating at steady state and were within an acceptable range of the target operating conditions.
Due to complications associated with the analysis of samples, only CBZ, TRIM, ATEN and ACE could be successfully quantitated. CBZ was found to not have been transformed to any appreciable level across all conditions investigated through either the IFAS SBBRs or control SBRs. ACE was transformed at efficiencies greater than 99% under all conditions and in both IFAS and control reactors and therefore no comparison could be made. TRIM and ATEN demonstrated improved transformation efficiencies under all conditions within the IFAS reactors. The presence of IFAS media, SRT and temperature were all found to be statistically significant effects through ANOVA using a confidence limit of 95%.
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Investigation of endocrine disrupting compounds in membrane bioreactor and UV processesYang, Wenbo 12 January 2010 (has links)
Endocrine disrupting compounds (EDCs) in the environment have recently emerged as a major issue in Canada and around the globe. The primary objective of this thesis was to investigate the fate of EDCs in two wastewater treatment processes, membrane bioreactors (MBRs) and ultraviolet (UV) disinfection. Two submerged MBR systems using hollow fiber membranes from two membrane manufacturers were tested. The results from a bench-scale and a pilot scale MBR for the treatment of swine wastewater with high concentration of EDCs showed that over 94% of the estrogenic activity (EA) in the influent was reduced through the MBR process. Biological degradation was the dominant removal mechanism for the removal of EDCs in MBRs. Over 85% of the influent EA was reduced by biodegradation through the MBR process. The other MBR system was built to study the removal mechanisms of two estrogens in a hybrid MBR with the addition of powdered activated carbon (PAC). The effects of PAC dosing on MBR overall performance was studied as well. It was found that PAC dosing could increase the removal rates of 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) by 3.4% and 15.8%, respectively and result in a slower rate of trans-membrane pressure (TMP) increase during MBR operation, which could significantly reduce the operating cost for membrane cleaning and/or replacement. The operating cost for PAC dosing could be offset by the benefit achieved from reducing the cost for membrane maintenance. The slower rate of TMP increase in the PAC-MBR was associated with the lower concentrations of soluble extracellular polymeric substances and colloidal organic compounds in the PAC-MBR sludge.
The degradation kinetics of three estrogens, estrone (E1), E2, and EE2 in de-ionized water by UV irradiation was studied. The experimental results showed both the apparent concentrations and overall EA of all three investigated estrogens in water decreased with direct UV irradiation. To further study the impact of UV on the overall EA of wastewater, the EA of pre-UV and post-UV samples from five wastewater treatment plants were measured in both liquid and solid phase by Yeast Estrogen Screen assay. It was found that the EA of wastewater decreased after UV disinfection in three of the investigated plants whereas it increased in the other two plants. This observation needs to be further studied because it might have significant impacts on the application of UV systems for wastewater disinfection.
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Fate and Transformation of Metal-(Oxide) Nanoparticles in Wastewater TreatmentBarton, Lauren Elizabeth January 2014 (has links)
<p>The study and application of materials possessing size dimensions in the nano scale range and, as a result, unique properties have led to the birth of a new field; nanotechnology. Scientists and engineers have discovered and are exploiting the novel physicochemical characteristics of nanoparticles (NPs) to enhance consumer products and technologies in ways superior to their bulk counterparts. Escalating production and use of NPs will unavoidably lead to release and exposure to environmental systems. This introduction of emerging potential contaminant NPs will provide new and interesting challenges for exposure and risk forecasting as well as environmental endurance.</p><p>The ultimate goal of this research is to develop a framework that incorporates experimental and computational efforts to assess and better understand the exposure of metal and metal-oxide NPs released to wastewater treatment plants (WWTPs) and further implications on land application units (LAUs) where biosolids can be applied. The foundation of the computational effort is comprised of Monte Carlo mass balance models that account for the unique processes affecting NP fate and transport through the different technical compartments of a WWTP and LAU. Functional assay and bioreactor experiments in environmental media were used to determine parameters capable of describing the critical processes that impact the fate of NPs in wastewater. </p><p>The results of this research indicate that a simplified, but still environmentally relevant nano-specific exposure assessment is possible through experimentation to parameterize adapted models. Black box modeling efforts, which have been shown in previous studies, show no disadvantage relative to discretization of technical compartments as long as all key transport and fate mechanisms are considered. The distribution coefficient (_), an experimentally determined, time-dependent parameter, can be used to predict the distribution of NPs between the liquid and solid phase in WWTPs. In addition, this parameter can be utilized a step further for the estimation of the more fundamental, time independent attachment efficiency between the NPs and the solids in wastewater. The NP core, size, and surface coating will influence the value of these parameters in addition to the background particle characteristics as the parameters are specific to the environmental system of study. For the metal and metal-oxide NPs studied, preferential overall association of approximately 90% or greater with the solid phase of wastewater was observed and predicted. </p><p>Furthermore, NP transformations including dissolution, redox reactions, and adsorption can potentially impact exposure. For example, experimental results showed that nano-CeO2 is reduced from Ce(IV) to Ce(III) when in contact with wastewater bacteria where Ce2S3 will likely govern the Ce(III) phase in biosolids. From the literature, similar transformations have been observed with Ag and ZnO NPs to Ag2S and ZnS. With respect to TiO2 NPs, studies indicated that due to high insolubility, these NPs would not undergo transformation in WWTPs. The distribution and transformation rate coefficients can then be used in fate models to predict the NP species exposed to aquatic and terrestrial systems and environmentally relevant concentrations released from WWTPs. </p><p>Upon completion of the WWTP model, the predicted concentrations of NPs and NP transformation byproducts released in effluent and biosolids were attainable. A simple mass balance model for NP fate in LAUs was then developed to use this output. Results indicate that NP loading on LAUs would be very low but that build up over time to steady state could result in mass concentrations on the order of the typical level for the background metal in soil. Transport processes of plant uptake and leaching were expected to greatly impact the solid phase concentration of the NPs remaining in the LAU, while rainfall did not impart a significant influence upon variation between low and high annual amounts. The significance of this research is the introduction of a method for NP exposure assessment in WWTPs and subsequently in LAUs. This work describes and quantifies the key processes that will impact Ag, TiO2, CeO2 and ZnO NP fate and transport, which can inform future studies, the modeling community and regulatory agencies.</p> / Dissertation
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Occurrence, Fate, and Mobility of Antibiotic Resistant Bacteria and Antibiotic Resistance Genes among Microbial Communities Exposed to Alternative Wastewater Treatment SystemsHelt, Cassandra 10 1900 (has links)
The ubiquitous nature of antibiotic resistance and antibiotic resistance genes (ARGs) among environmental pathogens from a variety of wastewater effluents, suggests that the aquatic environment, and specifically alternative wastewater treatment systems, may act as reservoirs for drug resistant bacteria and ARGs, thereby contributing to the widespread dissemination of antibiotic resistance. More research is necessary to contribute to our understanding of the occurrence, fate, and mobility of antibiotic resistance and ARGs among bacterial indicators of faecal contamination as well as pathogenic bacteria within Canadian wastewater treatment systems. The primary objective of this research was to determine the prevalence, fate, and potential transfer of bacterial resistance and ARGs among selected environmental pathogens exposed to alternative wastewater treatment systems, while considering the impact of treatment strategies on the expression of antibiotic resistance. A detailed analysis was initially conducted with respect to the characterization and quantification of microbial populations (including antibiotic resistant bacteria) in a variety of treatment systems and waste effluent sources. Traditional culture-based screening techniques in combination with molecular characterization (through colony or multiplex PCR), and molecular quantification using real-time quantitative PCR were utilized in order to help establish a preliminary environmental assessment of selected pathogens (Escherichia coli, Enterococcus spp., Salmonella spp.) and ARGs (tetA, blaSHV, & ampC) within a variety of wastewater treatment systems (lab-scale mesocosms, constructed wetland, constructed lagoon system, and pilot-scale biological nutrient removal (BNR) system).
Overall, the level of multiple antibiotic resistance (MAR) among culturable indicator (E. coli & Enterococcus spp.) and environmental bacteria was high (reaching 100% in several instances) within different types of wastewater treatment systems and effluent sources (poultry waste effluent, municipal wastewater, aquaculture wastewater). Common antibiotic resistance profiles among E. coli isolates included simultaneous resistance to between three and five antimicrobials, whereas common MAR profiles among Enterococcus spp. isolates showed resistance to ten or more antibiotics. Real time quantitative PCR was used to determine the concentration of three bacterial pathogens; E. coli, Enterococcus faecalis, and Salmonella spp., and three ARGs; tetA, ampC, and blaSHV, within a variety of wastewater samples. Based on the results, it was concluded that high concentrations of ARGs were present in the treated effluent (10⁴- 10⁶ target gene copies/100 mL), regardless of system type (i.e. constructed lagoon, pilot-scale BNR, or constructed wetland), which may ultimately serve as a potential route for entry of ARGs and antibiotic resistant bacteria into the natural environment.
Water is considered an important medium for transfer of resistance genes and resistant bacteria to the broader environment. Few studies have examined the transferability via conjugation of ARGs in E. coli and Salmonella spp. isolated from wastewater. Identification of three resistance determinants (tetA, strA, strB) conferring resistance to tetracycline and streptomycin was performed on selected multi-drug resistant Salmonella spp. and E. coli isolates. The potential for transfer of tetracycline and streptomycin resistance genes was demonstrated through broth conjugation experiments using multi-drug resistant Salmonella spp. and E. coli isolates as donors, and E. coli K12 as the recipient. Conjugation was successfully observed in 75% (9/12) of donor isolates, occurring in both Salmonella spp. and E. coli isolates. Six strains (50%) were capable of transferring their tetA, strA, and strB genes to the recipient strain, resulting in 58.5% (38/65) of total transconjugant strains acquiring all three resistance determinants. The results confirm the role of environmental bacteria (isolated from wastewater treatment utilities) as a reservoir of antibiotic resistance and ARGs, containing mobile genetic elements, which are capable of disseminating and transferring ARGs. As concerns about water quality and environmental contamination by human and agricultural effluents have increased, it has become increasingly more important to consider the prevalence and transferability of ARGs to opportunistic and human pathogens.
As observed in this research, the ubiquitous nature of multi-drug resistant bacteria in water and wastewater effluents, the presence of diverse ARGs of human and veterinary health significance, as well as the transfer of resistance determinants through conjugative plasmids to recipient bacteria, suggests that environmental exposure through contact or consumption with contaminated water is probable. However, a lack of critical information still exists regarding the movement of resistance genes within and between microbial populations in the environment. In addition, the extent of human exposure to ARGs and antibiotic resistant bacteria is still not well understood, and future studies on human exposure to these resistant contaminants are necessary.
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The Physiology Of Microorganisms In Enhanced Biological Phosphorous RemovalSaunders, Aaron Marc Unknown Date (has links)
Enhanced biological phosphorus removal (EBPR) is a biological wastewater treatment process facilitated by polyphosphate-accumulating organisms (PAO). The absence of isolates that have the PAO phenotype has limited the scope of studies into the physiology of these industrially significant and metabolically unique organisms. This thesis outlines findings into the physiology and ecology of EBPR in mixed microbial cultures, which contribute to the fundamental understanding of the process. The first experimental approach used in these studies was to investigate the microbial abundance of identified PAOs and GAOs in full-scale and lab-scale EBPR processes, and correlate these data with chemical monitoring methods both at a macroscale and microscale. The macroscale studies consisted of process optimisation experiments that found propionate to be a more effective and stable carbon source than acetate. The microscale study investigated the activity of Competibacter, growing in dense aggregates. This study discovered that the structure of the granules affected the distribution of activity by limiting the supply of oxygen and that the activity of the Competibacter in turn affected the structure of the aggregate. The second experimental approach was to target key facets of the microbial physiology of PAOs and GAOs at a molecular level. Environmental gene expression studies were used to investigate the stimulus for the expression of a putative Accumulibacter polyphosphate kinase gene (ppk). This study found that the expression of this gene was repressed by high external phosphate concentrations, which suggests that the pho regulon is functioning in Accumulibacter. In another study, previously published models were integrated and elaborated to develop a model for the membrane transport processes in PAOs and GAOs, which give them the unique ability to sequester VFA without an electron acceptor. These studies confirmed that the proton-motive force (PMF) drives the uptake of VFA by both PAOs and GAOs and postulated fundamental differences in the molecular mechanisms that PAOs and GAOs use to create a PMF in the absence of respiratory electron transport. The studies also explain the molecular basis for findings in other studies that PAOs have a competitive advantage over GAOs at increased pH. The third experimental approach was to attempt to isolate organisms significant to EBPR. Some measure of success was achieved: colonies of Competibacter were obtained in pure culture but the growth could not be sustained further than the growth of micro-colonies just visible to the eye. EBPR microbiology, like many other subjects of inquiry in environmental microbiology, has benefited greatly from developments in molecular methods to identify and describe microbial communities. However, the investigation of microbial physiology in the environment remains a challenge; this thesis has taken up that challenge. Discoveries regarding the benefits of propionate as a carbon source and the basis for the competitive advantage that PAOs derive from an increased pH have potential application for practitioners of EBPR plants. Furthermore the findings make a contribution to the fundamental understanding of the physiology of EBPR organisms that may in the future lead to entirely novel approaches to EBPR optimisation.
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Ultraviolet disinfection system for constructed wetlands /Ly, Jong Chan. January 1900 (has links)
Thesis (M.S.)--Humboldt State University, 2008. / Includes bibliographical references (leaves 40-44). Also available via Humboldt Digital Scholar.
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Επεξεργασία αγρο-βιομηχανικών αποβλήτων και απομόνωση πολυφαινολών με τεχνολογία μεμβρανώνΖάγκλης, Δημήτριος 07 June 2013 (has links)
Η παρούσα εργασία είναι χωρισμένη σε τέσσερις θεματικές ενότητες. Στην πρώτη ενότητα παρουσιάζονται οι βασικές φυσικοχημικές μέθοδοι επεξεργασίας που χρησιμοποιήθηκαν, οι οποίες είναι η κροκίδωση/καθίζηση και η διήθηση με μεμβράνες, καθώς και οι βασικές αρχές που τις διέπουν.
Η δεύτερη ενότητα της παρούσας εργασίας αποτελείται από την παρουσίαση εφαρμογών της τεχνολογίας μεμβρανών σε συνδυασμό με απόσταξη υπό κενό και διάφορα προσροφητικά μέσα για την αντιμετώπιση προβλημάτων της οινοποιίας. Πιο συγκεκριμένα, εξετάστηκε η αφαίρεση πτητικής οξύτητας από ερυθρό και λευκό οίνο, που οδήγησε σε συνολική απομάκρυνση της τάξεως του 90%, καθιστώντας τον οξειδωμένο οίνο κατάλληλο προς πώληση. Επίσης εξετάστηκε η απομόνωση αιθανόλης και ταυτόχρονη παραγωγή οίνου με μειωμένο περιεχόμενο σε αλκοόλ. Με την προτεινόμενη μέθοδο παρήχθει διάλυμα αιθανόλης 23% vol και οίνος με μειωμένο αλκοόλ 6.7% vol. Τρίτη και τελευταία εφαρμογή ήταν η αφαίρεση αναγωγικών οσμών από λευκό οίνο, η οποία επιτεύχθηκε πλήρως με τη χρήση φίλτρου ενεργού άνθρακα.
Στην τρίτη ενότητα παρουσιάζεται μια διεργασία επεξεργασίας αποβλήτου βιομηχανίας χρωμάτων με το συνδυασμό ενός βήματος κροκίδωσης/καθίζησης με μεμβράνες υπερδιήθησης και αντίστροφης ώσμωσης. Το τελικό διήθημα της διεργασίας, από περίπου 20000 mg/l COD που είχε το αρχικό απόβλητο, έχει περίπου 50 mg/l COD, γεγονός που το καθιστά κατάλληλο για ανακύκλωση στη βιομηχανία, ή απόρριψη στο περιβάλλον.
Στην τέταρτη και τελευταία ενότητα παρουσιάζεται μια συγκριτική ανάλυση και ανάλυση βιωσιμότητας των διαθέσιμων μεθόδων επεξεργασίας αποβλήτου ελαιοτριβείου, βασισμένες στην αποδοτικότητα, το κόστος και το ενεργειακό αποτύπωμα της κάθε μεθόδου. Τέλος παρουσιάζεται μια μέθοδος επιλογής της καταλληλότερης μεθόδου επεξεργασίας σύμφωνα με τη βαρύτητα που δίνει κάποιος σε κάθε ένα από τα τρία προαναφερθέντα χαρακτηριστικά. / The present study is divided into four chapters. In the first chapter the psychochemical treatment methods that were used with the underlying basic principles are presented. These methods include coagulation/flocculation and membrane filtration.
The second chapter is concerned with the implementation of membrane filtration, combined with vacuum evaporation and adsorption materials, in order to address problems occurring in winery processes. More specifically, the removal of volatile acidity from red and white wine was tested, leading to its reduction by 90%, rendering oxidized wine suitable for distribution. Furthermore, the removal of ethanol and the production of low alcohol wine were tested. Through the proposed method, a solution with 23% vol of ethanol and wine with 6.7 vol % were produced. Third and last application was the removal of odors from white wine, which was accomplished through the use of activated carbon.
In the third chapter a process for the treatment of paint industry effluents with the combination of coagulation/flocculation with Ultrafiltration and Reverse Osmosis membranes is presented. The final effluent, compared to the initial COD which was around 20000 mg/l, had a 50 mg/l COD and was suitable for recycling in the industrial process or to be rejected to the environment.
In the fourth and final chapter a sustainability analysis and benchmarking of the existing treatment methods of Olive Mill Wastewater is presented, based on their effectiveness, cost and CO2 emissions. Finally, a selection technique for the most suitable method is presented, based on the weight given to each one of the aspects given above, by the user.
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