• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • 1
  • 1
  • Tagged with
  • 5
  • 5
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Sustainable development of an integrated solid waste and wastewater treatment

Wong, Ling Say January 2012 (has links)
This PhD thesis investigated solid and liquid waste treatment systems for Sureclean, a waste Management company based in the North of Scotland. Sureclean receives a diverse range of waste streams and the increasing need for sustainable development as well as stringent environmental legislation motivated this research to develop an integrated waste treatment system. Waste characterisation was conducted using a range of analytical instrumentation to identify the TPH, COD, heavy metals content, TOC, and particle size of Sureclean waste streams. From there, four treatment systems were investigated utilising Sureclean waste streams: mechanical separation, chemical treatment, electro-coagulation and the advanced oxidation process. Laboratory and field trials were conducted using these different treatment techniques and the analysis was performed to verify the treatment results. The result of these trials led to the development of four modular waste treatment units, that form the outcome of this research: the Sureclean Water Treatment System (SWTS), a filtration based mechanical separation system was shown to reduce the TSS, BOD and TOC content of an oily wastewater; the Sureclean Sludge Separation System (SSSTS), a chemical-enhanced filtration based system was demonstrated to reduce 52.6 % of the sewage sludge volume; the Sureclean Electro-coagulation Water Treatment System (SEWTS), a system that agglomerates colloid particles and demulsifies oil removed 99.9 % of TPH from Sureclean interceptor effluent; and the Sureclean Advanced Water Treatment System (SAWTS), an advanced oxidation process which was demonstrated to reduce the TPH of a contaminated groundwater collected from an ex-gas work. The treated effluent could be discharged to Sureclean interceptor. The four treatment units developed in this research expanded Sureclean waste treatment capabilities and an integrated system was developed to treat different waste streams and to improve the treatment efficiency thus increasing the revenue and future waste stream options for Sureclean.
2

Emprego dos processos de eletrofloculação e osmose inversa no tratamento de águas oleosas / The use of electroflocculation and reverse osmosis in the treatment of oily wastewater

Leonardo Firmino da Silva 26 February 2013 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A descarga desenfreada de águas residuais no meio ambiente, ao longo dos últimos anos, vem acelerando o processo de contaminação e degradação dos corpos hídricos no mundo. Tais rejeitos apresentam elevada carga de contaminantes e de concentração de matéria orgânica o que leva a mortandade das espécies pela concorrência ao oxigênio e, em casos extremos, a aceleração dos processos de eutrofização. Pensando nisso, o presente trabalho estudou um sistema híbrido, em batelada, de tratamento de águas oleosas simuladas em laboratório pela adição de um determinado óleo lubrificante em uma solução aquosa de agentes emulsificantes e eletrólito suporte. O sistema de tratamento foi composto de duas etapas, onde na primeira avaliou-se o uso da técnica da eletrofloculação, responsável por quebrar a estabilidade das emulsões óleo/água e de uma segunda que avaliou o uso de processos de separação com membranas visando à remoção do metal adicionado ao efluente na etapa anterior. O sistema de eletrofloculação foi avaliado em relação ao uso de eletrodos de alumínio e ferro com correntes elétricas de 1A, 2A e 3A, nos modos contínuo e alternado. Os resultados apontaram um maior consumo evidente de massa de eletrodos quando do uso da corrente contínua, 4,0337g 0,0132 para o alumínio e 3,8260g 0,0181 para o ferro ao passo que o consumo foi de 2,1400g 0,0099 para o alumínio e 2,4121g 0,0127 para o ferro quando do o uso da corrente alternada. Foram alcançadas remoções máximas de 98 % 0 da DQO, 99,77 % 0,27 de remoção da cor e 100 % 0 de remoção da turbidez para o uso de corrente alternada e eletrodos de alumínio enquanto se alcançaram remoções máximas 96 % 1 da DQO, 99,46 % 0,82 de remoção da cor e também 100 % 0 de remoção da turbidez no uso de eletrodos de ferro. Na segunda etapa do estudo, a osmose inversa, o sistema utilizado atingiu rejeições de 99,53 % 0,12; 99,56 % 0,13 e de 98,87 % 0,36, para pressões respectivas de 10, 20 e 30 bar. Além disso, foram obtidos fluxos crescentes de permeado 10,87 L/h.m2 0,25; 15,67 L/h.m2 0,53; 18,49 L/h.m2 0,74 com o também aumento da pressão. Ao final do estudo alcançou-se um efluente final com baixa carga orgânica e de metais, estando o mesmo apto ao lançamento nos corpos receptores. Entretanto, mecanismos de controle, sobretudo de pH devem ser incluídos no projeto desses sistemas uma vez que esse parâmetro sofre alterações ao longo do processo / The uncontrolled discharge of wastewater into the environment over the last years has accelerated the process of contamination and degradation of water bodies in the world. These wastes contain high amounts of contaminants and concentration of organic matter which leads to the death of several species due to lack of oxygen and, in extreme cases, acceleration of eutrophication processes. In the specific case of oily wastewater, the use of techniques such as chemical coagulation, dissolved air injection, membranes, biochemical and electrochemical processes are described. However some of these processes have limitations which range from the concentration of the contaminant in the effluent, limitations in the operating conditions and even cost constraints. With this in mind, this paper has studied a hybrid system, batch process, in the treatment of oily waters simulated in the laboratory by adding a specific lubricating oil in an aqueous solution with emulsifiers and supporting electrolyte. The treatment system was consisted of two stages, which in the first was evaluated the use of the technique of electrocoagulation, which was responsible by the breaking stability of oil/water emulsions and a second stage which evaluated the use of membrane separation processes in order to remove the metal added to the effluent in the previous stage. The electrofloculation system was evaluated in relation to the use of iron and aluminum electrodes with electrical currents of 1A, 2A and 3A, in the continuous and alternate modes. The results showed a higher apparent mass consumption of electrodes when using direct current, 4,0337 g 0,0132 for aluminum and 3,8260 g 0,0181 for iron while consumption was 2,1400 g 0,0099 for aluminum, and 2,4121 0,0127 g for the iron when the use of alternating current. Removals were reached maximum 98 % 0 COD, 99,77 % 0,27 color removal and 100 % 0 turbidity removal for use alternating current and aluminum electrodes while were reached maximum 96 % 1 of COD, 99,46 % 0, 82 color removal and also 100% 0 to remove the turbidity in the use of iron electrodes. In the second study phase, reverse osmosis, the system used has reached rejections 99,53 % 0,12, 99,56 % 0,13 and 98,87 % 0,36, corresponding to pressures of 10 , 20 and 30 bar Moreover, increasing flows were obtained permeate 10,87 L/h.m2 0,25, 15,67 L/h.m2 0,53; 18,49 L/h.m2 0,74 also with the increased pressure. At the end of the study was reached final effluent with low organic load and metals, it being able to release the bodies receptors. However, control mechanisms, particularly pH should be included in the design of such systems since this parameter changes over the process
3

Emprego dos processos de eletrofloculação e osmose inversa no tratamento de águas oleosas / The use of electroflocculation and reverse osmosis in the treatment of oily wastewater

Leonardo Firmino da Silva 26 February 2013 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A descarga desenfreada de águas residuais no meio ambiente, ao longo dos últimos anos, vem acelerando o processo de contaminação e degradação dos corpos hídricos no mundo. Tais rejeitos apresentam elevada carga de contaminantes e de concentração de matéria orgânica o que leva a mortandade das espécies pela concorrência ao oxigênio e, em casos extremos, a aceleração dos processos de eutrofização. Pensando nisso, o presente trabalho estudou um sistema híbrido, em batelada, de tratamento de águas oleosas simuladas em laboratório pela adição de um determinado óleo lubrificante em uma solução aquosa de agentes emulsificantes e eletrólito suporte. O sistema de tratamento foi composto de duas etapas, onde na primeira avaliou-se o uso da técnica da eletrofloculação, responsável por quebrar a estabilidade das emulsões óleo/água e de uma segunda que avaliou o uso de processos de separação com membranas visando à remoção do metal adicionado ao efluente na etapa anterior. O sistema de eletrofloculação foi avaliado em relação ao uso de eletrodos de alumínio e ferro com correntes elétricas de 1A, 2A e 3A, nos modos contínuo e alternado. Os resultados apontaram um maior consumo evidente de massa de eletrodos quando do uso da corrente contínua, 4,0337g 0,0132 para o alumínio e 3,8260g 0,0181 para o ferro ao passo que o consumo foi de 2,1400g 0,0099 para o alumínio e 2,4121g 0,0127 para o ferro quando do o uso da corrente alternada. Foram alcançadas remoções máximas de 98 % 0 da DQO, 99,77 % 0,27 de remoção da cor e 100 % 0 de remoção da turbidez para o uso de corrente alternada e eletrodos de alumínio enquanto se alcançaram remoções máximas 96 % 1 da DQO, 99,46 % 0,82 de remoção da cor e também 100 % 0 de remoção da turbidez no uso de eletrodos de ferro. Na segunda etapa do estudo, a osmose inversa, o sistema utilizado atingiu rejeições de 99,53 % 0,12; 99,56 % 0,13 e de 98,87 % 0,36, para pressões respectivas de 10, 20 e 30 bar. Além disso, foram obtidos fluxos crescentes de permeado 10,87 L/h.m2 0,25; 15,67 L/h.m2 0,53; 18,49 L/h.m2 0,74 com o também aumento da pressão. Ao final do estudo alcançou-se um efluente final com baixa carga orgânica e de metais, estando o mesmo apto ao lançamento nos corpos receptores. Entretanto, mecanismos de controle, sobretudo de pH devem ser incluídos no projeto desses sistemas uma vez que esse parâmetro sofre alterações ao longo do processo / The uncontrolled discharge of wastewater into the environment over the last years has accelerated the process of contamination and degradation of water bodies in the world. These wastes contain high amounts of contaminants and concentration of organic matter which leads to the death of several species due to lack of oxygen and, in extreme cases, acceleration of eutrophication processes. In the specific case of oily wastewater, the use of techniques such as chemical coagulation, dissolved air injection, membranes, biochemical and electrochemical processes are described. However some of these processes have limitations which range from the concentration of the contaminant in the effluent, limitations in the operating conditions and even cost constraints. With this in mind, this paper has studied a hybrid system, batch process, in the treatment of oily waters simulated in the laboratory by adding a specific lubricating oil in an aqueous solution with emulsifiers and supporting electrolyte. The treatment system was consisted of two stages, which in the first was evaluated the use of the technique of electrocoagulation, which was responsible by the breaking stability of oil/water emulsions and a second stage which evaluated the use of membrane separation processes in order to remove the metal added to the effluent in the previous stage. The electrofloculation system was evaluated in relation to the use of iron and aluminum electrodes with electrical currents of 1A, 2A and 3A, in the continuous and alternate modes. The results showed a higher apparent mass consumption of electrodes when using direct current, 4,0337 g 0,0132 for aluminum and 3,8260 g 0,0181 for iron while consumption was 2,1400 g 0,0099 for aluminum, and 2,4121 0,0127 g for the iron when the use of alternating current. Removals were reached maximum 98 % 0 COD, 99,77 % 0,27 color removal and 100 % 0 turbidity removal for use alternating current and aluminum electrodes while were reached maximum 96 % 1 of COD, 99,46 % 0, 82 color removal and also 100% 0 to remove the turbidity in the use of iron electrodes. In the second study phase, reverse osmosis, the system used has reached rejections 99,53 % 0,12, 99,56 % 0,13 and 98,87 % 0,36, corresponding to pressures of 10 , 20 and 30 bar Moreover, increasing flows were obtained permeate 10,87 L/h.m2 0,25, 15,67 L/h.m2 0,53; 18,49 L/h.m2 0,74 also with the increased pressure. At the end of the study was reached final effluent with low organic load and metals, it being able to release the bodies receptors. However, control mechanisms, particularly pH should be included in the design of such systems since this parameter changes over the process
4

Istovremeni uticaj permeabilnosti sloja, prečnika vlakna i ulazne koncentracije uljne faze na separaciju mineralnih ulja iz otpadnih voda / Simultaneous effect of bed permeability, fiber diameter and oil phase inlet concentration on the separation of mineral oils from wastewater

Sokolović Srđan 26 June 2020 (has links)
<p>Cilj ove doktorske disertacije je da d&acirc; doprinos u proučavanju nedovoljno poznatih fenomena koalescentne filtracije, kako bi se smanjio obim potrebnih poluindustrijskih istraživanja prilikom projektovnja filtera za neku konkretnu primenu. Svi materijali kori&scaron;ćeni u ovoj doktorskoj disertaciji su otpadni materijali, čija primena kao filtarskog punjenja predstavlja poseban doprinos održivom razvoju. Jedan od ciljeva ove doktorske disertacije je proučavanje istovremenog uticaja promene permeabilnosti sloja i debljine vlakana na osobine sloja, pad pritiska i efikasnost separacije dispergovanog ulja iz kontinualne vodene faze. Uticaj geometrije sloja proučavan je na slojevima homogene i heterogene geometrije po dubini. Realizovano je detaljno ispitivanje izgleda, morfologije vlakana, kao i strukture sloja, izgleda i rasporeda njegovih pora, primenom skening elektronske mikroskopije i optičke mikroskopije. U radu je dat pregled istraživanja primene vlakana različite prirode (slobodnih i međusobno povezanih, krutih i elastičnih, različite debljine te time i različite vijugavosti) i njihovih slojeva. Takođe, dat je doprinos proučavanju istovremenog uticaja promena ulazne koncentracije dispergovane faze i permeabilnosti sloja. U veći deo ostvarenih istraživanja ukjučeno je i proučavanje uticaja prirode uljne faze, pri čemu je neophodno istaći da su sva kori&scaron;ćena ulja mineralnog porekla. Cilj optimizacije rada koalescera bio je da se pronađu uslovi u kojima se postiže maksimalna vrednost kritične brzine uz minimalni pad pritiska.</p> / <p>The aim of this doctoral dissertation is to contribute to the study of insufficiently known phenomena of coalescent filtration, in order to reduce the number of pilot plant experiments required for designing filters for some specific applications. All the used materials are waste materials the use of which as a filter media contributes to sustainable development. One of the goals of this doctoral dissertation is to study the simultaneous effect of changes in bed permeability and fiber thickness on bed properties, pressure drop and the efficiency of the dispersed oil separation from a continuous aqueous phase. The effect of bed geometry was studied by applying the beds of homogeneous and heterogeneous geometry in depth. A detailed examination of the appearance and morphology of the fibers, as well as the structure of the bed and the appearance and arrangement of its pores, was performed by scanning electron microscopy and optical microscopy. The doctoral dissertation gives an overview of the testing of fibers of different nature (free and interconnected, rigid and elastic, of different thickness and thus of different meandering) and their beds. The simultaneous effect of the changes in the input dispersed phase concentration and the bed permeability was also investigated. Much of the conducted research includes the study of the impact of the nature of the oil phase, and it is necessary to point out that all used oils are mineral oils. The goal of optimizing the operation of a coalescer was to find the conditions providing the maximum critical velocity value with a minimum pressure drop.</p>
5

Treatment and characterisation of oily wastewaters

Karhu, M. (Mirjam) 18 August 2015 (has links)
Abstract Oily wastewaters are heterogeneous, containing various types of oils, surfactants from detergents, metals etc. Oily wastewaters are produced from a wide range of industries such as metalworking, petroleum refineries, the petrochemical industry, transportation as well as the textile and food industries. Oily wastewaters, especially those containing stable oil-in-water emulsions, require advanced treatment as conventional treatment methods have their limitations to meet ever-stricter environmental regulations. Ultrafiltration is a widely accepted and commonly used treatment method for oily wastewaters. The first aim of this thesis was to increase knowledge concerning the performance of an industrial-scaled ultrafiltration-based process treating concentrated real oily wastewaters. The demand for a more effective pre-treatment method for ultrafiltration to enhance performance and decrease fouling of membrane was observed. The second aim of the thesis was to investigate the suitability and efficiency of different methods for treating concentrated model oil-in-water emulsions and real oily wastewaters. The treatment methods studied were electrocoagulation (electrolytic dissolution of anodic metal), conventional coagulation-flocculation followed by either sedimentation or dissolved air flotation, and dissolved air flotation utilising cationic air bubbles. Electrocoagulation was discovered to be a promising treatment method for various types of oil-in-water emulsions. Dissolved air flotation with cationic modified air bubbles was proven to be an efficient method with even higher treatment results with smaller chemical doses when compared to conventional coagulation-flocculation followed by dissolved air flotation. The biodegradation of various components is an important measure of their impact on the environment in case of spillage. The third aim of the thesis was to explore the biodegradability of different types of oils and surfactants in solution conditions and soils. It was discovered that the biodegradation of light fuel oil continued during a three-month time period, reaching a biodegradation degree of over 60% in mineral-rich soil. For surfactants, their distinct effect on the biodegradation of organic material in soil was observed, and it masked the biodegradation of the surfactants themselves. / Tiivistelmä Öljyiset jätevedet ovat heterogeenisiä, sisältäen mm. erityyppisiä öljyjä, metalleja ja pesuaineiden pinta-aktiivisia aineita. Öljyisiä jätevesiä muodostuu laajalti eri teollisuuksista, kuten metallintyöstöstä, öljyn jalostuksesta, petrokemian teollisuudesta, ruoka- ja tekstiiliteollisuudesta sekä liikenteestä. Öljyiset jätevedet, varsinkin stabiileja öljyemulsioita sisältävät, vaativat tehokkaan käsittelymenetelmän, jotta ympäristölainsäädännön ja luvituksen ehdot täyttyvät. Ultrasuodatus on yleisesti käytössä oleva öljyisten jätevesien käsittelymenetelmä. Tämän väitöstyön ensimmäinen tavoite oli lisätä tietoutta teollisen mittakaavan konsentroituneiden öljyisten jätevesien ultrasuodatusprosessien tehokkuudesta. Prosessien strategisista kohdista kerättyjen öljyisten jätevesien karakterisointitulosten perusteella havaittiin, että ennen ultrasuodatusta tarvitaan tehokas esikäsittelyvaihe prosessin tehostamiseksi ja ultrasuodattimen tukkeutumisen vähentämiseksi. Täten toinen väitöstyön tavoite oli selvittää eri menetelmien soveltuvuutta ja tehokkuutta konsentroituneiden malliaineina käytettyjen öljyemulsioiden ja öljyisten jätevesien käsittelyssä. Tutkitut käsittelymenetelmät olivat elektrokoagulaatio (sähkökemiallinen flokkaavien metalli-ionien liuottaminen anodilta), koagulaatio-flokkulaatio ja laskeutus/korkeapaineflotaatio sekä korkeapaineflotaatiomenetelmä, joka hyödyntää kationisia ilmakuplia. Elektrokoagulaation todettiin olevan erittäin tehokas käsittelymenetelmä, jolla saavutettiin korkeat puhdistustulokset erityyppisille öljyemulsioille. Korkeapaineflotaatiolla, joka hyödyntää kationisia ilmakuplia, saavutettiin hyvät puhdistustulokset jopa pienemmillä kemikaalimäärillä verrattuna perinteiseen koagulaatio-flokkulaatioon ja korkepaineflotaation. Erilaisten komponenttien biohajoavuus on tärkeä suure arvioitaessa niiden ympäristövaikutuksia. Väitöstyön kolmas tavoite oli selvittää erilaisten öljyjen ja pinta-aktiivisten aineiden biohajoavuutta erilaisissa liuosolosuhteissa ja maa-aineksissa. Tärkeimmät biohajoavuustutkimustulokset olivat, että kevyt polttoöljy saavutti kolmen kuukauden mittauksen aikana yli 60 % biohajoavuusasteen mineraalirikkaassa maa-aineksessa. Pinta-aktiivisten aineiden havaittiin lisäävän huomattavasti maan orgaanisen aineksen biohajoamista, ja tämä vaikeutti itse pinta-aktiivisten aineiden biohajoamisen arviointia.

Page generated in 0.0925 seconds