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The Extractive Membrane Bioreactor : flux enhancement and biofilm controlStrachan, Laura Fay January 1997 (has links)
No description available.
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The interactions of toluic acid with indigenous microbial populations in a model Gravel Bed Hydroponic systemFuller, Robert A. January 1996 (has links)
No description available.
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Biodegradação e bioconversão do d-limoneno por bactérias isoladas de esgoto doméstico / Biodegradation and bioconversion of d-limonene by bacteria isolated from wastewaterOliveira, Sheila de, 1974- 07 February 2013 (has links)
Orientador: Everson Alves Miranda / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-23T06:45:13Z (GMT). No. of bitstreams: 1
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Previous issue date: 2013 / Resumo: As indústrias cítricas geram grandes quantidades de efluentes líquidos. Estes efluentes são potencialmente poluidores para descarte em corpos d'água e necessitam de tratamento adequado. A maioria das plantas de tratamento de efluentes cítricos utiliza processos biológicos, devido a custos operacionais mais baixos quando comparado aos processos físico-químicos. Porém, estas plantas têm apresentado problemas de eficiência de remoção da carga orgânica e inibição da atividade biológica, em função das características tóxicas do efluente cítrico, devido à presença residual do d-limoneno, um monoterpeno extraído da casca da laranja. O d-limoneno, quando separado e purificado, tem ampla aplicação industrial, na área cosmética como fragrância e na área alimentícia como agente antimicrobiano e também pode ser bioconvertido em produtos como ácidos e alcoóis perílicos e carvona que podem ser utilizados na terapia do câncer. Os objetivos deste estudo foram selecionar e identificar microrganismos capazes de degradar o d-limoneno em altas concentrações (até 5%), simulando condições similares aos efluentes cítricos e avaliar o comportamento de consórcio destes microrganismos. Também foi avaliada a qualificação dos produtos obtidos da bioconversão do d-limoneno. Os microrganismos foram isolados a partir do lodo ativado de uma estação de tratamento de esgotos. Uma pré-seleção, de 56 linhagens de bactérias foi realizada, durante as 3 etapas de enriquecimento com o d-limoneno, através da técnica de esgotamento em superfície. Foram selecionadas 10 linhagens, que apresentaram maior crescimento visual, que foram caracterizados através da morfologia, coloração diferencial (Gram) e análise filogenética. A biodegradação do d-limoneno foi avaliada pela remoção de DQO em meios de cultivos diferentes variando as concentrações de d-limoneno (1%, 3% e 5%) sob condição agitada e estática na temperatura de 30°C. A bioconversão dos produtos foi qualificada por cromatografia gasosa. Foram isoladas bactérias Gram-positivas, do gênero Bacillus resistentes à concentração de 5% de d-limoneno sem fonte complementar de carbono. A remoção de DQO foi de 77% e terpineol, alcoóis ciclodecanol e octanediol foram qualificados como produtos bioconvertidos / Abstract: The citrus' industries generate large quantities of wastewater. These effluents are potentially polluting to disposal in water bodies and require treatment. Most sewage treatment plants citrus use biological process due to lower operating costs compared to physical-chemical processes. However these plants have presented problems in the efficiency removal of organic charge and inhibition of the biological activity due to citric toxic characteristics because of the presence of residual d-limonene, a monoterpene extracted from orange peel. The d-limonene, when it is separated and purified, has large industrial application, on field cosmetics as fragrances and foods fields as antimicrobial agent. Besides, the d-limonene can be bioconverted in perillic acids and perillyl alcohol, ?-terpineol and carvone that can be used in cancer therapy. The achievement of this study was select and isolate microorganism able to degradation high containing limonene (since 5%), simulating the same condition of wastewater characterizes of citric plants and evaluated the consortium microorganism behavior. In addition, the products of biotransformation d-limonene were qualified. Microorganisms were isolated from activated sludge of sewage treatment plant. A pre-selection, with 56 strains, was undertaken, during the 3 stage of enrichment with d-limonene, using depletion technique to isolate microorganisms. Ten strains were selected that showed the greater visual growth. They were characterized through of morphology, Gram and phylogenetic analysis. The d-limonene biodegradation was determinate by reduction COD in different cultivation media, varying the concentration of d-limonene (5 %, 3 % and 1 %) in agitated and stationary condition at temperature 30°C. The bioconversion of product obtained was confirmed by gas chromatography. Gram-positive bacteria were isolated of the Bacillus genus, bacteria resist to 5% of limonene-containing without complementary source of carbon. The removal of COD was 77% and terpineol, cyclodecanol and octadienol was evaluated as products bioconverted / Mestrado / Desenvolvimento de Processos Biotecnologicos / Mestra em Engenharia Química
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The biological treatment of metalworking fluids : insights into carbon removal mechanisms and integration with biocide toxicity mitigation strategiesSingh, Shivashkar January 2016 (has links)
The biological treatment of metalworking fluids (MWFs) is a cost effective alternative to conventional waste disposal processes. While research has proven that this process is capable of treating large volumes of wastes with high organic concentrations, there are uncertainties about the mechanisms by which the treatment occurs, and there are limitations that must be overcome. There is a need to understand the importance of the mechanisms by which carbon (and hence COD) is removed from the wastewater. This will allow for waste practitioners to make better decisions for optimizing the process, and for disposing of waste (i.e sludge) that is generated. The biological treatment process is also susceptible to biocides present within formulations. These compounds either need to be removed before the treatment process, or the bioreactors need to be made more resistant to them to ensure that their presence does not hinder the reactor functioning. This study aims to answer the uncertainties about the carbon removal mechanisms involved in the treatment of oil-containing MWFs. In the first experimental chapter, it is shown that the predominant mechanism of carbon removal is oil/water separation induced by emulsifier degradation, and hence the bioprocess treatment rate is significantly affected by the biodegradability of surfactants and by the presence of cations found naturally in the water that used to prepare the emulsions. The study then provides insights into the potential that coagulation and coalescence has for removing inhibitory components commonly found in MWFs. Coagulation and coalescence is shown to effectively remove biocides with low aqueous solubility (iodopropynyl butylcarbamate) and those that partition themselves into the oil phase (o-phenyl phenate and its sodium salt). Finally, to improve the resistance of reactors to inhibitory compounds, factors influencing the development of fixed-film reactors are investigated. A micro-cosmic system is used to study the both physico-chemical effects and nutritional factors on the development of biofilm reactors. It is shown that biofilm yields can be controlled through pH adjustment, and that these yields are maximized with phosphate stimulation and ammonium limitation. It is then shown that fixed-film reactors are able to treat metalworking fluids even under conditions deemed to be inhibitory. In summary, this project provides insights into further understanding and enhancing the biological treatment of MWFs.
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Design and Optimization of Membrane Filtration and Activated Carbon Processes for Industrial Wastewater Treatment Based on Advanced and Comprehensive Analytical Characterisation MethodologiesAlizadeh Kordkandi, Salman January 2019 (has links)
Aevitas is an industrial wastewater treatment plant that receives about 300 m3/day of mixture of wastewater from different industries. The chemical oxygen demand of higher 600 ppm and the variety of the chemical constitution of industrial wastewater are two significant problems on Aevitas. Therefore, there is a strong need for developing advanced analytical techniques that can identify the specific compounds that are the source of COD. During 10 months, about 75 industrial samples were characterized using a battery of tests including GC/MS, COD, TOC, and pH to identify the chemicals that are main source of COD in the industrial wastewaters. Results showed that the COD of 87% of 75 provided samples from Aevitas plant was higher than 600.
At the first step of process design, activated carbon was used to eliminate the identified organic chemicals from the wastewaters. The maximum and minimum of COD removal (depends on the chemical composition) of the wastewaters were obtained as 94 and 24%, respectively. Moreover, the amount of COD and TOC that can be adsorbed on the surface of 1 gram of the activated carbon were 25 and 7 mg, respectively. Although activated carbon is capable to reduce the COD, its capacity of adsorption is limited. To overcome this problem an alternative process, membrane filtration was applied for COD removal. Two types of crossflow NF (NF270, NF90, NFX, NFW, NFS, TS80, XN45, and
SXN2_L) and RO (BW60 and TW30) membranes in two modules of the spiral wound and flat sheet were used. The filtration results of 11 different industrial wastewaters showed that NF90, TS80, NFX, and NFS were effective in COD removal. However, in terms of output flux NFX and NFS flat sheet were better than others were. Similar to the activated carbon process, the COD removal in filtration process was between 30 and 90%. The obtained results can be used to scale up the membrane filtration process at Aevitas. / Thesis / Master of Chemical Engineering (MChE) / Aevitas is an industrial wastewater treatment plant, which is situated at the City of Brantford.
Every day, this plant receives about 15 trucks of the mixture of wastewaters from many different industries. The input wastewater into the plant should be treated and meet the environmental standard so that it can be discharged into a municipal wastewater plant. Currently, the maximum allowable chemical oxygen demand (COD) for discharging the treated wastewater from Aevitas to the municipal wastewater treatment plant is 600 ppm. Despite the fact, the current system in Aevitas is not efficient to meet this criterion. Thus, we strive to design efficient processes to overcome the problem. To this end, 75 samples were collected from Aevitas to observe the kind of chemicals that are the source of COD and then, two processes including activated carbon adsorption and membrane filtration were used for further reduction of COD. Although activated carbon can reduce the COD, the limited adsorption capacity was a major concern for its long-term application, especially if the COD of influent wastewater is higher than 2000 ppm. Membrane filtration was used as an
alternative for activated carbon and the results showed that membrane could reduce the
COD below 600 in 48% of the cases.
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Photocatalytic treatment of industrial wastewater containing citric acid and toxic heavy metalsBaloyi, Siwela Jeffrey 12 1900 (has links)
M. Tech. (Chemical Engineering, Faculty of Engineering and Technology), Vaal University of Technology| / The co-existence of organic acids and toxic heavy metals in natural water creates harmful effects on human, plants and animals. Therefore, it is necessary to treat organic acids and toxic heavy metal contaminated wastewater prior to its discharge to the environment. The aim of this study was to apply co-treatment of industrial wastewater containing citric acid and toxic heavy metals in single and binary systems using photocatalysis process. The hydrothermal method was used to synthesise dandelion-like TiO2 structures. Modifications of the dandelion-like TiO2 by deposition of gold nanoparticles and immobilisation on calcium alginate were done using deposition precipitation and one-step encapsulation methods, respectively. Dandelion-like TiO2 and dandelion-like TiO2 immobilised on calcium alginate (Alg/TiO2) were used as photocatalysts for Cr(VI), Hg(II) and citric acid removal from water.
The results showed that the production of dandelion-like TiO2 structures strongly depends on the reaction time and synthesis temperature as key process parameters. The characterisation of the dandelion-like TiO2 by X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) and Brunauer-Emmett-Teller (BET) revealed the crystal structure, morphology, chemical composition and surface area. It was found that the efficiency of photocatalytic process depends on the type of pollutants, initial pH of the solution, photocatalyst dosage, contact time, substrate initial concentration, UV wavelength and light intensity. The reduction efficiency of Cr(VI) ion and citric acid increased with decreasing the initial pH values and initial concentration. On the other hand, Hg(II) reduction efficiency increased with increasing the initial pH values and initial concentration. In a binary system, the reduction of Cr(VI) and Hg(II) was found to be faster than in the single and ternary systems. The relationship of the chemical reaction rate of Cr(VI), Hg(II) and citric acid were expressed by the pseudo-first-order kinetic equation. Addition of ferric ions to Cr(VI)-citric acid complex and Hg(II)-citric acid complex enhanced the reduction of Cr(VI) and Hg(II), a complete reduction was accomplished within 30 and 60 minutes (min) of irradiation time, respectively. The reduction efficiency of both Cr(VI) and Hg(II) in the presence of citric acid in a solution was still significant after four times of Alg/TiO2 reuse. These results indicated that the UV/TiO2 photocatalysis process can be considered as a suitable method to reach a complete reduction of Cr(VI) and Hg(II) in the presence of citric acid in a solution.
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Ανάπτυξη μεθόδων για την επιλογή της καλύτερης διαθέσιμης τεχνολογίας για την επεξεργασία υγρών βιομηχανικών αποβλήτων / Development of a decision – supporting tool for the selection of best available technology for industrial wastewater treatmentΓεωργιοπούλου, Μάρθα 22 May 2008 (has links)
Η επιλογή της καλύτερης διαθέσιμης τεχνολογίας για την επεξεργασία βιομηχανικών αποβλήτων που προέρχονται από μια δεδομένη πηγή απαιτεί μια καλά δομημένη και περιεκτική μεθοδολογία για συστηματική αποτίμηση των εναλλακτικών τεχνολογιών. Μια κατάλληλη μεθοδολογία για την επιλογή ενός ολοκληρωμένου συστήματος διαχείρισης βιομηχανικών απόβλητων από περιβαλλοντική και οικονομική άποψη αναπτύσσεται και εφαρμόζεται σε μια βιομηχανία γάλακτος. Προκειμένου να επιλεγεί το πιο φιλικό προς το περιβάλλον και το περισσότερο οικονομικό ολοκληρωμένο σύστημα επεξεργασίας, διαφορετικές τεχνολογίες επεξεργασίας βιομηχανιών αποβλήτων εξετάστηκαν. Τα συστήματα επεξεργασίας αποτελούνται από εναλλακτικές διεργασίες προεπεξεργασίας, τεχνολογίες βιολογικής επεξεργασίας (αερόβιες και αναερόβιες) και την επεξεργασία της ιλύος. Αναπτύχθηκε ένα μοντέλο τύπου ριζόχαρτου που υπολογίζει την κατανάλωση των υλικών, της ενέργειας, των κύριων αναλωσίμων και τις εκπομπές που συνδέονται με τις φάσεις οικοδόμησης και λειτουργίας των εναλλακτικών τεχνολογιών επεξεργασίας. Στη συνέχεια χρησιμοποιήθηκε η μεθοδολογία της Ανάλυσης Κύκλου Ζωής (ΑΚΖ) για να υπολογιστούν ποσοτικά οι πιθανές περιβαλλοντικές επιπτώσεις σε κάθε περίπτωση. Οι επιλογές που βασίζονται στην αναερόβια χώνευση αναδείχθηκαν ότι είναι περισσότερο φιλικές προς το περιβάλλον και οδηγούν σε λιγότερες εκπομπές. / The selection of the best available technology for the treatment of industrial wastewater originating from a given source requires a well structured and comprehensive methodology for the systematic evaluation of the alternative technologies. A suitable methodology for the selection of an integrated system of management of industrial wastewater from the environmental and economic viewpoints is developed and applied to a milk industry. In order to select the environmentally friendlier and most economic integrated treatment system, different industrial wastewater treatment technologies were considered. The treatment systems consisted of alternative pretreatment processes, biological treatment technologies (aerobic and anaerobic) and sludge treatment. A spreadsheet model that calculates the consumption of materials, energy, main consumables and emissions associated with both the construction and operation phases of the alternative treatment technologies was constructed. The Life Cycle Assessment (LCA) methodology was then used to quantify the potential environmental impacts in each case. Options based on anaerobic digestion were found to be the most environmentally friendly leading to fewer emissions.
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Ontology based model framework for conceptual design of treatment flow sheetsKoegst, Thilo 09 April 2014 (has links) (PDF)
The primary objective of wastewater treatment is the removal of pollutants to meet given legal effluent standards. To further reduce operators costs additional recovery of resources and energy is desired by industrial and municipal wastewater treatment. Hence the objective in early stage of planning of treatment facilities lies in the identification and evaluation of promising configurations of treatment units. Obviously this early stage of planning may best be supported by software tools to be able to deal with a variety of different treatment configurations.
In chemical process engineering various design tools are available that automatically identify feasible process configurations for the purpose to obtain desired products from given educts. In contrast, the adaptation of these design tools for the automatic generation of treatment unit configurations (process chains) to achieve preset effluent standards is hampered by the following three reasons.
First, pollutants in wastewater are usually not defined as chemical substances but by compound parameters according to equal properties (e.g. all particulate matter). Consequently the variation of a single compound parameter leads to a change of related parameters (e.g. relation between Chemical Oxygen Demand and Total Suspended Solids). Furthermore, mathematical process models of treatment processes are tailored towards fractions of compound parameters. This hampers the generic representation of these process models which in turn is essential for automatic identification of treatment configurations.
Second, treatment technologies for wastewater treatment rely on a variety of chemical, biological, and physical phenomena. Approaches to mathematically describe these phenomena cover a wide range of modeling techniques including stochastic, conceptual or deterministic approaches. Even more the consideration of temporal and spatial resolutions differ. This again hampers a generic representation of process models.
Third, the automatic identification of treatment configurations may either be achieved by the use of design rules or by permutation of all possible combinations of units stored within a database of treatment units. The first approach depends on past experience translated into design rules. Hence, no innovative new treatment configurations can be identified. The second approach to identify all possible configurations collapses by extremely high numbers of treatment configurations that cannot be mastered. This is due to the phenomena of combinatorial explosion. It follows therefrom that an appropriate planning algorithm should function without the need of additional design rules and should be able to identify directly feasible configurations while discarding those impractical.
This work presents a planning tool for the identification and evaluation of treatment configurations that tackles the before addressed problems. The planning tool comprises two major parts. An external declarative knowledge base and the actual planning tool that includes a goal oriented planning algorithm. The knowledge base describes parameters for wastewater characterization (i.e. material model) and a set of treatment units represented by process models (i.e. process model). The formalization of the knowledge base is achieved by the Web Ontology Language (OWL).
The developed data model being the organization structure of the knowledge base describes relations between wastewater parameters and process models to enable for generic representation of process models. Through these parameters for wastewater characterization as well as treatment units can be altered or added to the knowledge base without the requirement to synchronize already included parameter representations or process models. Furthermore the knowledge base describes relations between parameters and properties of water constituents. This allows to track changes of all wastewater parameters which result from modeling of removal efficiency of applied treatment units.
So far two generic treatment units have been represented within the knowledge base. These are separation and conversion units. These two raw types have been applied to represent different types of clarifiers and biological treatment units.
The developed planning algorithm is based on a Means-Ends Analysis (MEA). This is a goal oriented search algorithm that posts goals from wastewater state and limit value restrictions to select those treatment units only that are likely to solve the treatment problem. Regarding this, all treatment units are qualified according to postconditions that describe the effect of each unit. In addition, units are also characterized by preconditions that state the application range of each unit. The developed planning algorithm furthermore allows for the identification of simple cycles to account for moving bed reactor systems (e.g. functional unit of aeration tank and clarifier). The evaluation of identified treatment configurations is achieved by total estimated cost of each configuration.
The planning tool has been tested on five use cases. Some use cases contained multiple sources and sinks. This showed the possibility to identify water reuse capabilities as well as to identify solutions that go beyond end of pipe solutions. Beyond the originated area of application, the planning tool may be used for advanced interrogations. Thereby the knowledge base and planning algorithm may be further developed to address the objectives to identify configurations for any type of material and energy recovery.
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Experimental and computational studies on sulphate removal from mine water by improved lime precipitationNurmesniemi, E.-T. (Emma-Tuulia) 13 November 2018 (has links)
Abstract
Lime precipitation has been used for the treatment of mine water for decades; however, the impact of precipitation conditions is not adequately known. In this thesis, four aspects related to the removal of sulphate from mine water by lime precipitation are considered: the effect of magnesium on lime precipitation, the utilisation of by-products in lime precipitation, enhancement of lime precipitation, and utilisation of the precipitate.
Sulphate removal in the presence of magnesium at the commonly used lime precipitation treatment pH of 9.6 was found unefficient as magnesium was keeping the sulphate soluble in the form of magnesium sulphate. At higher treatment pH of 11.5, magnesium that was naturally present in the mine water was shown to precipitate as magnesium hydroxide, which could serve as seed crystals for gypsum or co-precipitate sulphate thus enhancing sulphate removal.
Quicklime manufacturing generates by-products that, currently, have few applications. The by-products examined in this study were successfully applied for mine water neutralization replacing commercial lime products. These by-products were found to remove sulphate equally well from the mine water. However, differences between by-products were observed in the consumption, and produced sludge quantities and qualities.
An enhanced lime precipitation method is the precipitation as ettringite, which was used to reduce the sulphate content in mine water to less than the value set as the drinking water guideline in Finland. Furthermore, the formed precipitate was found to remove arsenate from the model solution. / Tiivistelmä
Vaikka kalkkisaostusta on käytetty kaivosten vesienkäsittelyyn useiden vuosikymmenten ajan, tieto olosuhteiden vaikutuksesta käsittelyn tehokkuuteen sulfaatin poiston osalta on puutteellista. Tämä väitöskirja käsittelee sulfaatinpoistoa kaivosvesistä kalkkisaostuksen avulla neljällä eri osa-alueella: magnesiumin vaikutus kalkkisaostukseen, kalkinpolton sivutuotteiden hyödyntäminen kalkkisaostuksessa, kalkkisaostuksen tehostaminen ja muodostuvan saostuman hyödyntäminen.
Magnesiumin todettiin kokeellisesti ja laskennallisesti haittaavan sulfaatin poistoa kaivosvedestä kalkkisaostuksessa yleisesti käytetyssä pH:ssa 9.6 pitämällä sulfaattia liukoisessa muodossa magnesiumsulfaattina. Korkeammassa pH:ssa 11.5 puolestaan kaivosveden luontaisesti sisältämän magnesiumin havaittiin kokeellisesti ja laskennallisesti saostuvan magnesiumhydroksidina, joka voi toimia siemenkiteinä kipsille tai kerasaostaa sulfaattia ja siten tehostaa sulfaatin poistoa.
Kalkinpolton sivutuotteina muodostuu jakeita, joille ei tällä hetkellä ole juurikaan käyttökohteita. Tässä työssä käytettiin kalkinpolton sivutuotteita korvaamaan kaupallista kalkkia kaivosveden neutraloinnissa. Sivutuotteet poistivat sulfaattia yhtä tehokkaasti kuin kaupalliset kalkkituotteet. Sivutuotteiden välillä havaittiin eroja niiden kulutuksessa sekä muodostuvan lietteen määrässä ja laadussa.
Saostuksella ettringiittinä, joka on tehostettu versio perinteisestä kalkkisaostuksesta, saavutettiin sulfaattipitoisuuden lasku alle Suomessa juomavedelle käytetyn suositusarvon. Lisäksi havaittiin muodostuneen ettringiittisaostuman olevan potentiaalinen materiaali arsenaatin poistoon vedestä.
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Ontology based model framework for conceptual design of treatment flow sheetsKoegst, Thilo 06 December 2013 (has links)
The primary objective of wastewater treatment is the removal of pollutants to meet given legal effluent standards. To further reduce operators costs additional recovery of resources and energy is desired by industrial and municipal wastewater treatment. Hence the objective in early stage of planning of treatment facilities lies in the identification and evaluation of promising configurations of treatment units. Obviously this early stage of planning may best be supported by software tools to be able to deal with a variety of different treatment configurations.
In chemical process engineering various design tools are available that automatically identify feasible process configurations for the purpose to obtain desired products from given educts. In contrast, the adaptation of these design tools for the automatic generation of treatment unit configurations (process chains) to achieve preset effluent standards is hampered by the following three reasons.
First, pollutants in wastewater are usually not defined as chemical substances but by compound parameters according to equal properties (e.g. all particulate matter). Consequently the variation of a single compound parameter leads to a change of related parameters (e.g. relation between Chemical Oxygen Demand and Total Suspended Solids). Furthermore, mathematical process models of treatment processes are tailored towards fractions of compound parameters. This hampers the generic representation of these process models which in turn is essential for automatic identification of treatment configurations.
Second, treatment technologies for wastewater treatment rely on a variety of chemical, biological, and physical phenomena. Approaches to mathematically describe these phenomena cover a wide range of modeling techniques including stochastic, conceptual or deterministic approaches. Even more the consideration of temporal and spatial resolutions differ. This again hampers a generic representation of process models.
Third, the automatic identification of treatment configurations may either be achieved by the use of design rules or by permutation of all possible combinations of units stored within a database of treatment units. The first approach depends on past experience translated into design rules. Hence, no innovative new treatment configurations can be identified. The second approach to identify all possible configurations collapses by extremely high numbers of treatment configurations that cannot be mastered. This is due to the phenomena of combinatorial explosion. It follows therefrom that an appropriate planning algorithm should function without the need of additional design rules and should be able to identify directly feasible configurations while discarding those impractical.
This work presents a planning tool for the identification and evaluation of treatment configurations that tackles the before addressed problems. The planning tool comprises two major parts. An external declarative knowledge base and the actual planning tool that includes a goal oriented planning algorithm. The knowledge base describes parameters for wastewater characterization (i.e. material model) and a set of treatment units represented by process models (i.e. process model). The formalization of the knowledge base is achieved by the Web Ontology Language (OWL).
The developed data model being the organization structure of the knowledge base describes relations between wastewater parameters and process models to enable for generic representation of process models. Through these parameters for wastewater characterization as well as treatment units can be altered or added to the knowledge base without the requirement to synchronize already included parameter representations or process models. Furthermore the knowledge base describes relations between parameters and properties of water constituents. This allows to track changes of all wastewater parameters which result from modeling of removal efficiency of applied treatment units.
So far two generic treatment units have been represented within the knowledge base. These are separation and conversion units. These two raw types have been applied to represent different types of clarifiers and biological treatment units.
The developed planning algorithm is based on a Means-Ends Analysis (MEA). This is a goal oriented search algorithm that posts goals from wastewater state and limit value restrictions to select those treatment units only that are likely to solve the treatment problem. Regarding this, all treatment units are qualified according to postconditions that describe the effect of each unit. In addition, units are also characterized by preconditions that state the application range of each unit. The developed planning algorithm furthermore allows for the identification of simple cycles to account for moving bed reactor systems (e.g. functional unit of aeration tank and clarifier). The evaluation of identified treatment configurations is achieved by total estimated cost of each configuration.
The planning tool has been tested on five use cases. Some use cases contained multiple sources and sinks. This showed the possibility to identify water reuse capabilities as well as to identify solutions that go beyond end of pipe solutions. Beyond the originated area of application, the planning tool may be used for advanced interrogations. Thereby the knowledge base and planning algorithm may be further developed to address the objectives to identify configurations for any type of material and energy recovery.
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