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  • 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.
81

Etude du potentiel de valorisation énergétique ou matière de composés organiques extraits de lixiviats de déchets ménagers / Energetic valorization and soil enrichment with organic compounds extracted from a landfill leachate

Baccot, Camille 16 December 2016 (has links)
Les contraintes techniques et économiques induites par la gestion des lixiviats de déchets ménagers et assimilés (LDMA) pourraient être minimisées en considérant le LDMA non plus comme un déchet mais comme un « co-produit » partiellement valorisable. Parmi la diversité des constituants des LDMA, la matière organique dissoute (MOD) présente 2 intérêts majeurs : une forte charge et des processus de transformations comparables à ceux de la matière organique naturelle (MON). Ce travail de thèse s’attache donc à extraire cette MOD des LDMA selon son caractère hydrophobe et à identifier des axes de valorisation. Seules les fractions de type hydrophobe (HPO*) et transphilique (TPH*), de par leurs caractéristiques et leur réactivité, ont été considérées dans cette étude et 2 voies de valorisation ont été testées : une valorisation énergétique et une valorisation matière par amendement sur un sol en déficit de carbone organique (Corg).La caractérisation des fractions de MOD anthropiques et leur comparaison à des fractions de MON a confirmé l’intérêt majeur de leur valorisation. En effet, elles sont (i) physiquement et chimiquement comparables à la MON, (ii) quantifiables à des concentrations jusqu’à plus de 1000 fois supérieures à la MON permettant ainsi un potentiel d’extraction conséquent en comparaison aux matrices environnementales telles que les eaux de surface, et (iii) plus facilement biodégradables que la MON, tout en ne présentant aucun caractère phytotoxique avéré.Un test BMP optimisé et adapté au LDMA a été développé via un plan d’expérience, puis utilisé pour mettre en évidence l’impact du caractère hydrophobe de la MOD du LDMA sur la digestion anaérobie, et notamment la production de méthane. Selon les résultats obtenus, les molécules organiques de type transphilique favorisent la production de biogaz. De plus, la fraction hydrophile, faiblement aromatique, diminue la teneur en méthane du biogaz, contrairement à la fraction hydrophobe.Enfin, l’amendement de fractions organiques extraites de LDMA présente un réel intérêt dans le cas d’un sol initialement pauvre en Corg. La fraction HPO* permet un apport de Corg plus important comparé à la fraction TPH*, tandis que les composés transphiliques favorisent l’activité biologique du sol.Ce travail de thèse a ainsi mis en évidence l’intérêt d’extraire les fractions hydrophobe (HPO*) et transphilique (TPH*) de la MOD de LDMA afin de les engager dans des processus de valorisation énergétique et agronomique. / The management of municipal solid waste leachates (MSWL) is technically and economically restrictive. It thus should be interesting to consider this effluent no more as a waste but rather as a partially valorizable “co-product”. The dissolved organic matter (DOM) is one of the major components of MSWL and presents a twofold interest: a high load and comparable processes of transformation to those of natural organic matter (NOM).This study thus aimed at extracting the DOM from MWSL according to its hydrophobic character and identifying ways of valorization. Only hydrophobic (HPO*) and transphilic (TPH*) fractions were considered because of their characteristics and reactivity. Two different ways of valorization were investigated: energetic valorization and enrichment of a soil with low content in organic carbon (Corg).The characterization of HPO* and TPH* fractions and their comparison with fractions of NOM confirmed their high valorizable potential. Indeed, they are physically and chemically comparable to NOM, they can be quantified at concentrations up to 1000 times higher than NOM (high extraction potential when compared to environmental matrices such as surface water), and they are more easily biodegradable than NOM without any phytotoxic character.An optimized BMP test was first developed by using an experimental design to adapt the experimental conditions to the digestion of MSWL. It was then applied in different conditions to highlight the impact of the hydrophobic character of the DOM of MSWL on the anaerobic digestion, and mainly on methane production. According to the results, the transphilic-like organic molecules improve the biogas production. Besides, the hydrophilic-like compounds with low aromatic character decrease the methane content of the produced biogas contrary to the hydrophobic fraction.Finally, organic fractions extracted from MSWL were relevant to enrich soil with low content in organic carbon. The HPO* fraction better improves the Corg content when compared to the TPH* fraction whereas transphilic-like molecules enhances the soil biological activity.With the results of this research study, the HPO* and TPH* fractions extracted from a MSWL can thus be considered both to produce biogas and particularly methane and to be amended on soils. Their extraction can thus be economically viable and their treatment no more highly costly.
82

Risk Based Post Closure Care Analysis for Florida Landfills

Sizirici Yildiz, Banu 24 March 2009 (has links)
Subtitle D of the Resource Conservation and Recovery Act (RCRA) requires a post closure period of 30 years for non hazardous wastes in landfills. Post closure care (PCC) activities under Subtitle D include leachate collection and treatment, groundwater monitoring, inspection and maintenance of the final cover, and monitoring to ensure that landfill gas does not migrate off site or into on site buildings. The decision to reduce PCC duration requires exploration of a performance based methodology to Florida landfills. PCC should be based on whether the landfill is a threat to human health or the environment. Historically no risk based procedure has been available to establish an early end to PCC. Landfill stability depends on a number of factors that include variables that relate to operations both before and after the closure of a landfill cell. Therefore, PCC decisions should be based on location specific factors, operational factors, design factors, post closure performance, end use, and risk analysis. The question of appropriate PCC period for Florida’s landfills requires in depth case studies focusing on the analysis of the performance data from closed landfills in Florida. Based on data availability, Davie Landfill was identified as case study site for a case by case analysis of landfill stability. The performance based PCC decision system developed by Geosyntec Consultants was used for the assessment of site conditions to project PCC needs. The available data for leachate and gas quantity and quality, ground water quality, and cap conditions were evaluated. The quality and quantity data for leachate and gas were analyzed to project the levels of pollutants in leachate and groundwater in reference to maximum contaminant level (MCL). In addition, the projected amount of gas quantity was estimated. A set of contaminants (including metals and organics) were identified as contaminants detected in groundwater for health risk assessment. These contaminants were selected based on their detection frequency and levels in leachate and ground water; and their historical and projected trends. During the evaluations a range of discrepancies and problems that related to the collection and documentation were encountered and possible solutions made. Based on the results of PCC performance integrated with risk assessment, projection of future PCC monitoring needs and sustainable waste management options were identified. According to these results, landfill gas monitoring can be terminated, leachate and groundwater monitoring for parameters above MCL and surveying of the cap integrity should be continued. The parameters which cause longer monitoring periods can be eliminated for the future sustainable landfills. As a conclusion, 30 year PCC period can be reduced for some of the landfill components based on their potential impacts to human health and environment (HH&E).
83

Avaliação da remoção de nitrogênio e fósforo em banhados construídos para o tratamento combinado de esgoto sanitário e lixiviado de aterro sanitário estabilizado

Ospitia Thola, Beatriz Eugenia January 2015 (has links)
O lixiviado, líquido complexo gerado nos aterros sanitários e depósitos de lixo a céu aberto, apresenta características de um poluidor em potencial, de difícil tratamento, devido a processos físico-químicos e de decomposição biológica dos resíduos sólidos no aterro sanitário, somado à infiltração de água de chuva. Formas de atenuar e tratar esse tipo de efluente vão desde tratamentos biológicos até técnicas avançadas de oxidação, sendo estes últimos de alto custo em sua infraestrutura, operação e manutenção. Uma alternativa adotada nos últimos tempos por muitas cidades de Brasil e o mundo inteiro é o tratamento combinado de lixiviado de aterro sanitário com esgoto sanitário, por ter vantagens custo-benefício viáveis. Na presente pesquisa foi avaliada a remoção de nutrientes, como nitrogênio e fósforo, em três sistemas de banhados construídos em escala piloto operados em paralelo (sistemas B1, B2, e B3), sendo cada um deles composto por duas unidades em série de fluxo vertical seguidos por duas unidades em série de fluxo horizontal de escoamento subsuperficial, plantados com macrófitas emergentes L. Peruviana e Typha sp., respectivamente, para tratar a combinação de 10 % de lixiviado de aterro sanitário estabilizado com 90 % de esgoto sanitário afluente à ETE Canoas, com tratamento prévio (B1: UASB+CBR e B2: UASB) e sem tratamento prévio (B3: esgoto bruto/lixiviado), com taxa de aplicação superficial de 400L/m2.dia e aplicação em bateladas com períodos de aproximadamente 15 minutos. O estudo foi desenvolvido na estação climática de inverno da região Sul do Brasil, no qual a remoção média de amônio (N-NH4+) foi maior que 95 % nos três banhados não sendo observada diferença significativa para p> 0,05, entre eles, enquanto que a remoção de nitrato (NO3-) foi provavelmente limitada pela baixa relação carbono/nitrogênio (C/N). O fósforo total (PT) apresentou remoções maiores que 45 % nos três sistemas sem diferença significativa, porém foi observada diferença significativa para a remoção de ortofosfato (P-PO4-) (p> 0,05) no banhado B3, quando este mostrou remoção negativa. A remoção de N e P pela absorção das plantas (L. Peruviana e Typha sp.) foi de aproximadamente 1 % e 2 % respectivamente, comparado com a remoção destes nutrientes na fase líquida. A precipitação e evapotranspiração não apresentaram influência na remoção de nutrientes. / The leachate, complex liquid generated in landfills and open dumps, has characteristics of a potential polluter, difficult to treat due to physical and chemical processes and biological decomposition of solid waste in landfills, added to rainwater infiltration. Ways to mitigate and treat this type of effluent range from biological treatments to advanced oxidation techniques, the latter being of high cost in its infrastructure, operation and maintenance. An alternative adopted recently by many cities of Brazil and the whole world is the combined treatment of landfill leachate with sanitary sewer, having advantages viable cost-effective. In the present study the removal of nutrients such as nitrogen and phosphorus were evaluated, in three pilot scale constructed wetlands systems, operated in parallel, (systems B1, B2 and B3) consisting each one of two vertical flow units in series followed by two horizontal flow units of subsurface flow, planted with emerging macrophytes L. peruviana and Typha sp., respectively, to treat the combination of 10% of stabilized landfill leachate with 90% of urban raw wastewater from ETE Canoas, with previous treatment (B1: UASB+CBR and B2: UASB) and untreated (B3: raw sewage / leachate), with superficial application rate of 400 L / m2.day, fed in batch periods of approximately 15 minutes. The study was conducted during the winter season in the southern region of Brazil, in which the average removal of ammonium (N-NH4+) was higher than 95 % in the three systems without significant difference among them (p> 0.001) and the removal of nitrate (NO3-) was probably limited by the low ratio carbon / nitrogen (C / N). The total phosphorus (PT) removal was greater than 45 % without significant difference among the three systems however a significant difference was observed for orthophosphate (P-PO4-) (p> 0.05) removal at B3 system, when it showed a negative removal. The nitrogen and phosphorous removal due to the absorption by the plants (L. peruviana and Typha sp.) was approximately 1 % and 2 % respectively, compared to the removal of the nutrients in the liquid phase. The precipitation and evapotranspiration did not caused influence upon the nutrients removal.
84

Using bioaugmentation to enhance the denitrification process in a treatment plant for landfill leachate

Skirfors, Oscar January 2020 (has links)
It has been illegal to deposit household waste in Swedish landfills since 2005. The large amount of waste deposited prior to this does however continue to pose an environmental concern, mainly in the form of leachate water. This study focused on enhancing the denitrification process in a leachate water treatment plant through bioaugmentation. The two strains Brachymonas denitrificans and Comamonas denitrificans as well a commercial seed mix from ClearBlu Environmental® (CBE-mix) containing amongst others, Pseudomonas putida AD 21 and Pseudomonas fluorescens, were investigated as candidates. Nitrite, nitrate, and ammonium concentrations were measured in laboratory-, and pilot-scale studies to follow the processes of nitrification and denitrification. The pilot study was conducted for 10 days in the middle of May 2020 with leachate from the treatment plant in an aerated and nonaerated setup in open field conditions. C. denitrificans and B. denitrificans were both shown to be able to adapt to growth in landfill leachate. The addition of these strains led to a higher rate of nitrate reduction compared to the control during the first days of the pilot experiment but showed no difference in the total amount of nitrate reduced. The combined nitrogen concentration of ammonium, nitrate, and nitrite was 6.7% lower than the control when using a culture augmented with the CBE-mix in the aerated setup. This could indicate aerated denitrification. The amount of nitrate reduced during the pilot experiment was increased with 32% when augmenting the community with the CBE-mix in a nonaerated setup. An explanation could be that certain strains in the mix were able to utilize hard to degrade organic carbon present in the leachate or that the mix had a higher ratio of reduced nitrate to consumed organic carbon than the indigenous community. / Det har varit olagligt att deponera hushållsavfall i Sverige sedan 2005, den stora mängd avfall som deponerats innan dess fortsätter dock att utgöra ett miljöproblem, främst genom genereringen av lakvatten. Den här studien fokuserade på möjligheten att förbättra denitrifikationen i ett reningsverk för lakvatten genom bioaugmentation. Två stammar tillhörande Brachymonas denitrificans, och Comamonas denitrificans, samt en kommersiell bakterieblandning från ClearBlu Environmental® innehållande bland andra Pseudomonas putida AD 21 och Psedomonas flourescens, undersöktes som möjliga kandidater. Ammonium-, nitrat- och nitritkoncentrationer mättes i odlingsstudier i labbskala och i en pilotstudie för att undersöka nitrifikation och denitrification. Pilotstudien utfördes i en luftad och en o luftad konfiguration utomhus i mitten av maj 2020, med lakvatten från reningsverket under en 10 dagars period. C. denitrificans och B. denitrificans klarade båda av att anpassa sig till tillväxt i lakvatten. Tillsats av dessa arter ledde till en ökning i nitratreduktionshastighet i början av pilotexperimentet men gav ingen total minskning av nitratmängden. Den sammanlagda slutkoncentrationen av ammonium-, nitrat- och nitritkväve var 6,7% lägre än i kontrollen när en kultur argumenterad med den kommersiella bakteriemixen användes i den luftade konfigurationen. Mängden reducerat nitrat ökade med 32% när en kultur augmenterad med den kommersiella mixen användes i den oluftade konfigurationen. En möjlig förklaring är att vissa stammar i mixen klarade av att tillgodogöra sig svårnedbrytbara kolföreningar i lakvattnet eller att ration mellan reducerat nitrat mot konsumerat organiskt kol var högre än i det ursprungliga microbsamhället.
85

Optimizing the nitrogen removal in leachate treatment during continuous-flow biological treatment (KBR) / Optimering av kvävereningen i lakvatten under kontinuerlig biologisk rening (KBR)

De Luca, Leandra Anali January 2021 (has links)
Användandet av deponier är en av de vanligaste metoderna för avfallshantering globalt. Trots insatser som gjordes för att förbjuda hushållsavfall i deponier under millennieskiftet, deponier skapade innan restriktionerna är fortfarande en risk för miljön. Under 2014 öppnade SÖRAB en kontinuerlig biologisk reningsanläggning (KBR-anläggning) på Löt Avfallsanläggning för att hantera lakvatten från en gammal deponi som under en tid fylldes med hushållsavfall. Sedan dess har SÖRAB arbetat med att förbättra KBR-anläggningen. Målet med denna studie är att utforma en driftstrategi för KBR-anläggningen för att förbättra kvävereningen vid låga temperaturer. Ett antal laborativa försök genomfördes, såsom den mikrobiella konsortiets livsduglighet i lakvattnet och tillväxten i både rumstemperatur och vid 4°C, bioaugmentation genom att berika den mikrobiella cellkulturen som redan finns i lakvattnet och hur detta förbättrar kvävereningen i jämförelse med tillsatser av den kommersiella bakterieblandningen ClearBlu Environmental och andra externa kolkällor. Resultaten från dessa laborativa försök påvisade komplett nitrifikation i både rumstemperatur och 4°C i berikat lakvatten från KBR-anläggningens L2A bassäng efter fem dagar. Försöket visade även på syresatt denitrifikation. Dessutom påvisades komplett denitrifikation inom fem dagar, vid rumstemperatur i lakvatten från anläggningens L2B bassäng. Under efterföljande pilotförsök påvisades möjligheten till upplivandet av den biologiska kvävereningen genom berikningen av den mikrobiella cellkulturen i lakvattnet. I ett pilotförsök då lakvatten från L2B bassängen berikades, komplett denitrifikation skedde under en anaerob fas på 16 dagar samt nitrifikation och aerob denitrifikation under ett påföljande 17 dagar lång aerob fas. Ett annat pilotförsök då lakvatten från L2A bassängen berikades påvisade både aerob och anaerob nitrifikation, då ammoniumrening skedde i både den syresatta och syrefria fasen. Tillsatsen av nutrient broth (näringsbuljong) kan påverka KBR-anläggningen, vilket kväver vidare studier. Resultatet från detta projekt tydligt påvisar att kvävereningen i KBR-anläggningen kan förbättras genom att berika den redan närvarande mikrobiella kulturen. / Landfilling has been one of the most popular methods of handling waste globally. Despite the efforts made to stop the disposal of household waste during the turn of the millennia, the landfills formed before these restrictions are still at risk for causing harm to the environment. In 2014, SÖRAB opened a continuous-flow biological treatment (KBR) facility in Löt to treat the leachate produced in one of their older landfills, once filled with household waste. Since then, SÖRAB has been working on improving the treatment facility. The aim of this the study is to find a suitable process to enhance the nitrogen removal at low temperature. Several laboratory scale experiments were performed, such as viability of microbial consortia in the leachate and growth at room temperature and at 4°C, testing bioaugmentation by enriching the microbial cell culture in the leachate and their efficiency in removing nitrogen, compared to the commercial cell culture ClearBlu Environmental and carbon source addition. The results displayed complete nitrification at both room temperature and 4°C in bioaugmented, enriched leachate originating from the L2A basin of the KBR facility, after five days. These trials also suggested the occurrence of aerated denitrification. Complete denitrification within five days was seen at room temperature in bioaugmented, enriched leachate from the L2B basin of the same facility. The ensuing pilot scale trials proved the possibility to revive the biological nitrogen removal by microbial cell culture enrichment. In one pilot in which leachate from the L2B basin was enriched, complete denitrification in the anaerobic phase consisting of 16 days occurred, along with some nitrification and aerated denitrification in the 17 day long aerated phase that followed. Another pilot scale trail in which leachate from the L2A basin was enriched, both aerobic and anaerobic nitrification occurred, as ammonium removal occurred in both the aerated and unaerated phases. The addition of nutrient broth might influence the KBR system which needs further study. The results from this project clearly demonstrate that nitrogen removal in the KBR facility could be enhanced using a culture naturally present in the facility.
86

Management strategy of landfill leachate and landfill gas condensate

Zhao, Renzun 15 October 2012 (has links)
Studies were conducted to evaluate the impact of landfill leachate discharge on the operation of waste water treatment plants (WWTPs). Two aspects of interferences were found: one is UV quenching substances, which are bio-refractory and able to penetrate the biological treatment processes, consequently interfere the UV disinfection in WWTPs. The other one is organic nitrogen, which can pass the nitrification-denitrification process and contribute to the effluent total nitrogen (TN). Also, treatability study was conducted for landfill gas (LFG) condensate. In a laboratory study, leachate samples were fractionated into humic acids (HA), fulvic acids (FA) and Hydrophilic (Hpi) fractions, the specific UV254 absorbance (SUVA254) of the three fractions follows: HA > FA > Hpi. However, the overall UV254 absorbance of the Hpi fraction was important because there was more hydrophilic organic matter than humic or fulvic acids. It was found that the size distribution of the three fractions follows: HA > FA > Hpi. This indicates that membrane separation following biological treatment is a promising technology for the removal of humic substances from landfill leachates. Leachate samples treated in this manner could usually meet the UV transmittance requirement of the POTWs. Also, nitrogen species in landfill leachates under various stabilization states were investigated. Although the effect of landfill stabilization state on the characteristics of organic matter and ammonia is well documented, there are few investigations into the landfill leachate organic nitrogen under different stabilization stages. Ammonia was found to leach out slower than organic matter and can maintain a constant level within the first a couple of years (< 10 years). The concentration and biodegradability of organic nitrogen were found to decrease with landfill age. A size distribution study showed that most of organic nitrogen in landfill leachates is < 1 kDa. The protein concentration was analyzed and showed a strong correlation with the organic nitrogen. Different slopes of regression curves of untreated and treated leachates indicate that protein is more biodegradable than the other organic nitrogen species in landfill leachates. XAD-8 resin was employed to isolate the hydrophilic fraction of leachate samples, hydrophilic organic nitrogen was found to be more biodegradable/bioavailable than the hydrophobic fractions. Furthermore, biological and physical-chemical treatment methods were applied to a landfill biogas (LFG) condensate to explore the feasible treatment alternatives for organic contaminant and arsenic removal efficiency. Sequencing batch reactor (SBR) showed effectiveness for the degradation of organic matter, even in an environment containing high levels of arsenic. This indicated a relatively low toxicity of organic arsenic as compared to inorganic arsenic. However, for arsenic removal, oxidation-coagulation, including biological oxidation, conventional oxidation and advanced oxidation followed by ferric salt coagulation, and carbon adsorption were not effective for what is believed to be tri-methyl arsenic. Among these, advanced oxidation-coagulation showed the best treatment efficiency (15.1% removal). Only reverse osmosis (RO) could reduce the arsenic concentration to an acceptable level to meet discharge limits. These results implied high stability and low toxicity of organic arsenic. / Ph. D.
87

Advanced Technologies for Resource Recovery and Contaminants Removal from Landfill Leachate

Iskander, Syeed Md 25 April 2019 (has links)
Landfill leachate contains valuable, recoverable organics, water, and nutrients. This project investigated leachate treatment and resource recovery from landfill leachates by innovative methods such as forward osmosis (FO), bioelectrochemical systems (BES), and advanced oxidation. In this study, a microbial fuel cell (MFC) removed 50-75% of the ammonia from a leachate through the electricity driven movement of ammonium to the cathode chamber followed by air stripping at high pH (> 9). During this process, the MFC system removed 53-64% of the COD, producing a net energy of 0.123 kWh m-3. Similarly, an integrated microbial desalination cell (MDC) in an FO system recovered 11-64% of the ammonia from a leachate; this was affected by current generation and hydraulic retention time in the desalination chamber. The MDC-FO system recovered 51.5% of the water from a raw leachate. This increased to 83.5% when the FO concentrate was desalinated in the MDC and then recirculated through the FO unit. In addition, the project investigated humic acid (HA) recovery from leachate during the synergistic incorporation of FO, HA recovery, and Fenton's oxidation to enhance leachate treatment and to reduce Fenton's reagent requirements. This led to the investigation of harmful disinfection byproducts (DBPs) formation during Fenton's oxidation of landfill leachate. The removal of leachate UV-quenching substances (humic, fulvic, and hydrophilic acids) using an MFC and a chemical oxidant (i.e., sodium percarbonate) with a focus on energy production and cost efficiency were also studied. BES treatment can reduce leachate organics concentrations; lower UV absorbance; recover ammonia; and, in combination with FO, recover water. Although BES is promising, significant work is needed before its use in landfill leachate becomes practical. FO application to leachate treatment must consider the choice of an appropriate draw solute, which should require minimal effort for regeneration. Resources like HA in leachate deserve more attention. Further efforts can focus on purification and application of the recovered products. The emerging issue of DBP formation in leachate treatment also requires attention due to the potential environmental and human health effects. The broader impact of this study is the societal benefit from more sustainable and cost-efficient leachate treatment. / Doctor of Philosophy / On average, each of us produces 3 – 4 pounds of solid waste every day. In the U.S., the yearly generation of solid waste is 250 million tons, while the global generation is 1.1 billion tons. The global management cost of solid waste is around 200 billion dollars. About half of U.S. municipal solid waste ends up in landfills, in China, this number is 80%. Among the different municipal solid waste (MSW) management approaches, landfilling is the most common because of its low cost and relatively low maintenance requirements. In a landfill, the combination of precipitation and solid waste degradation produce leachate, a complex wastewater. A ton of municipal solid waste can generate 0.05–0.2 tons of leachate in its lifetime during the process of landfilling. Leachate contains a vast array of pollutants, which can result in major environmental impact and adverse human health risk if not contained and treated appropriately. At present, leachate is mostly treated biologically, without any resource recovery. Among the myriad recoverable resources in landfill leachates, water and ammonia are the most abundant. We applied innovative approaches such as, bioelectrochemical systems, forward osmosis, advanced oxidation to recover resources and remove contaminants from leachate simultaneously. We also incorporated these novel technologies to help each other. For instance, we recovered humic fertilizer from leachate prior to advanced oxidation (i.e., Fenton’s oxidation) that helped the reduction of Fenton’s reagent requirements. The next step of our study could be the pilot scale application of the proposed techniques so that it can be applied in field. The broader impacts of this study include improvements in sustainability and cost efficiency of leachate treatment that can benefit the society.
88

Two - Stage AnMBR for Removal of UV Quenching Organic Carbon from Landfill Leachates: Feasibility and Microbial Community Analyses

Pathak, Ankit Bidhan 13 February 2017 (has links)
Landfilling is the most widely used method for the disposal of municipal solid wastes (MSW) in the United States due to its simplicity and low cost. According to the 2014 report on Advancing Sustainable Materials Management by the USEPA, only 34% of the total MSW generated in the US was recycled, while 13% was combusted for energy recovery. In 2014, 53% of the MSW generated, (i.e. 136 million tons) in the US was landfilled. The treatment of landfill leachates, generated by percolation of water through the landfill, primarily due to precipitation, has been found to be one of the major challenges associated with landfill operation and management. Currently, leachates from most landfills are discharged into wastewater treatment plants, where they get treated along with domestic sewage. Issues associated with treatment of landfill leachates due to their high nitrogen and heavy metal content have been widely studied. Recently, it has been observed that the organic carbon in landfill leachates, specifically humic and fulvic acids (together referred to as "humic substances") contain aromatic groups that can absorb large amounts of ultraviolet (UV) light, greatly reducing the UV transmissivity in wastewater plants using UV disinfection as the final treatment step. This interference with UV disinfection is observed even when landfill leachates constitute a very small fraction (of the order of 1%) of the total volumetric flow into wastewater treatment plants. Humic substances are present as dissolved organic matter (DOM) and typically show very low biodegradability. Removing these substances using chemical treatment or membrane processes is an expensive proposition. However, the concentrations of humic substances are found to be reduced in leachates from landfill cells that have aged for several years, suggesting that these substances may be degraded under the conditions of long-term landfilling. The primary objective of this research was to use a two-stage process employing thermophilic pretreatment followed by a mesophilic anaerobic membrane bioreactor (AnMBR) to mimic the conditions of long-term landfilling. The AnMBR was designed to keep biomass inside the reactor and accelerate degradation of biologically recalcitrant organic carbon such as humic substances. The treatment goal was to reduce UV absorbance in raw landfill leachates, potentially providing landfills with an innovative on-site biological treatment option prior to discharging leachates into wastewater treatment plants. The system was operated over 14 months, during which time over 50% of UV-quenching organic carbon and 45% of UV absorbance was consistently removed. To the best of our knowledge, these removal values are higher than any reported using biological treatment in the literature. Comparative studies were also performed to evaluate the performance of this system in treating young leachates versus aged leachates. Next-generation DNA sequencing and quantitative PCR (qPCR) were used to characterize the microbial community in raw landfill leachates and the bioreactors treating landfill leachate. Analysis of microbial community structure and function revealed the presence of known degraders of humic substances in raw as well as treated landfill leachates. The total number of organisms in the bioreactors were found to be higher than in raw leachate. Gene markers corresponding to pathogenic bacteria and a variety of antibiotic resistance genes (ARGs) were detected in raw landfill leachates and the also in the reactors treating leachate, which makes it necessary to compare these ARG levels with wastewater treatment in order to determine if leachates can act as sources of ARG addition into wastewater treatment plants. In addition, the high UV absorbance of leachates could hinder the removal of ARBs and ARGs by UV disinfection, allowing their release into surface water bodies and aiding their proliferation in natural and engineered systems. / Ph. D.
89

Improving Wastewater Treatment and Management: A case study on a Combined Heat and Power Plant in Sweden / Förbättring av dag- och processvattenrening och hantering: En fallstudie på ett kraftvärmeverk i Sverige

Thunholm, Sara January 2024 (has links)
Vatten är en av de viktigaste resurserna för mänskligheten eftersom det är en nödvändighet för överlevnad men också en viktig faktor inom många industrier. Utöver detta är vattenförorening ett globalt problem som påverkar både miljön och människors hälsa. Många länder runt om i världen saknar fortfarande en hållbar vattenhantering inom många sektorer, varav en viktig är energiproduktionssektorn. Detta problem hotar inte bara mål 6: rent vatten och sanitet för alla, utan även fler av FNs globala mål. Händelöverket är ett stort kraftvärmeverk som har levererat fjärrvärme till Norrköping sedan 1982. Sedan dess har anläggningen utökats från två till fem pannor. För att säkerställa en kontinuerlig tillförsel av bränsle har bränslelagret utökats och är nu fyllt med bränslen som exempelvis träflis, gummi, återvunnet trä, kol och avfall. En ökad produktionskapacitet har även lett till en ökad mängd dag- och processvatten som måste behandlas. Ursprungligen byggdes en sedimenteringsbassäng för att behandla avloppsvatten från de två första pannorna. Idag används samma bassäng för att behandla allt dagvatten och processvatten från hela Händelöverkets område tillsammans med två efterföljande sandfilter. Syftet med denna studie var att undersöka möjliga förbättringar av vattenreningen av dagvatten och processvatten vid Händelöverket. Studien begränsades till att fokusera på två vattenströmmar, en som består av dagvatten från bränslelagret och en annan som är ansluten till den strömmen och samlar upp avrinningsvatten från avfallet i bunkern. Dessutom karakteriserades dessa avfallsströmmar med avseende på koncentration av metaller, kemisk syreförbrukning, biologisk syreförbrukning (7 dagar), suspenderade partiklar och pH. Baserat på resultaten presenterades tre olika förbättringsalternativ. Från Case 1 drogs slutsatsen att återcirkulering av avrinningsvatten från avfallet tillbaka in i bunkern var ett enkelt och ekonomiskt genomförbart alternativ. Dessutom skulle det resultera i en vattenhantering som är bättre anpassat till slutsatserna i Best Available Technology presenterat av Europeiska unionen. Dessutom skulle Case 1 inte heller påverka pannornas effektivitet väsentligt. Case 2 föreslog en förändring i hanteringsplanen för hanteringen av släckvatten om en brand skulle uppstå på bränsleytan eller i avfallet i bunkern. Från Case 2 drogs slutsatsen att denna plan bör förbättras genom att införa ytterligare bestämmelser om att leda släckvatten till den befintliga bergrumsvattenreningen som applicerar fällnings- och flockningsteknik. Slutligen fokuserade Case 3 på förbättringar som skulle kunna göras för att öka effektiviteten av behandling av zink, koppar, nickel och bly. Från dessa case drogs slutsatsen att implementering av en polymerblandare samt att flytta doseringsplatsen längre upp i sedimenteringssbassängen skulle vara det mest lämpliga första steget. Dessutom rekommenderades det också att installera ett fällningssteg före polymerdoseringen för att fälla ut metaller som fortfarande är i lösning och därmed öka renlighetsgraden ytterligare i processen. / Water is one of the most important resources for humanity as it is a necessity for survival but also an important factor within many industries. In addition to this, water pollution is a global concern affecting both the environment and human health. Many countries around the world still lack a sustainable water management within many sectors whereas one important one is energy production. This problem threatens not only goal 6: clean water and sanitation, but also many other of the sustainable development goals presented by the united nations development programme.  Händelöverket is a large combined heat and power plant supplying the city of Norrköping with district heating since 1982. Since then the plant has expanded from two to five boilers in operation. Additionally, to have a continuous supply of fuel, the storage area has been increased and is now filled with fuels like wood chips, rubber tires, recycled wood, coal and waste. An expanding production site has naturally led to an increased amount of storm- and process water that has to be treated. Originally a sedimentation was built to only treat waste water from two boilers. Today the same basin is used to treat all storm and process water from the entire site of Händelöverket together with the following sand filters.  The scope of this study was to investigate potential improvements of the waste water treatment of the storm- and process water treatment at Händelöverket. This study focused on two waste water streams: one consisting of storm water from the fuel yard, and stream another connected to it, which collects waste leachate water. Furthermore these waste flows were characterized in terms of metal concentration, chemical oxygen demand, biological oxygen demand, total suspended solids and pH. Based on the results, three different cases of improvements were presented. Case 1 concluded that recirculating of the waste leachate water back onto the waste material was a simple and economically feasible option. Furthermore it would result in a waste water management more aligned with Best available technology regulation presented by the European Union. Additionally it would not significantly effect the efficiency of the boilers. Case 2 proposed a change in the management plan for handling extinguishing water if a fire would occur on the fuel yard or within the waste material of the bunker. It was concluded that this plan should be improved to send water of similar quality to the other existing waste water treatment plant working with a coagulation and flocculation technique. Lastly Case 3 focused on improvements that could be made to the existing storm and process wastewater treatment process that could enhance the efficiency of treating zinc, copper, nickel and lead. It was concluded that implementing a polymer mixing tank and moving the dosing locationfurther up the sedimentation basin would be the most important first step. Furthermore it was also recommended to install a precipitation step before the polymer dosing to precipitate metals that are still in solution. By doing this the degree of purification will be increased further for the storm- and process water treatment.
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Estudo da tratabilidade do lixiviado de aterro sanitário pelos processos oxidativos avançados foto-Fenton, ozônio e ozônio combinado com peróxido de hidrogênio / Study of treatability of landfill leachate by advanced oxidation processes photo-Fenton, ozone and ozone combined with hydrogen peroxide

Monteiro, Luciano do Valle 05 June 2012 (has links)
O lixiviado de aterro sanitário possui constituição complexa e é altamente poluente. Neste contexto, os processos oxidativos avançados se destacam como pré-tratamento, objetivando a remoção ou diminuição da recalcitrância do lixiviado. Neste trabalho foram utilizados os Processos Oxidativos Avançados (POAs) foto-Fenton, ozônio e ozônio combinado com peróxido de hidrogênio. Avaliou-se a influência do pré-tratamento por air-stripping, a variação na produção de ozônio em 80 e 100%, a melhor dose de peróxido de hidrogênio correspondente a 20, 40 e 80% da dose de 6g O3/L empregada nos tratamentos com ozônio, a remoção de matéria orgânica, nitrogênio amoniacal total (NAT), alcalinidade, sólidos dissolvidos totais (SDT) (cloretos), produção de nitrito e nitrato, melhor razão molar [H2O2]/[Fe2+] para o tempo de contato de 80 min no foto-Fenton, uso do número médio de oxidação do carbono (NMOC) e a quantificação do ácido oxálico formado após a aplicação dos POAs. O tratamento por O3/H2O2 (1,2 g H2O2/L e produção de O3 em 80%) obteve a maior remoção de matéria orgânica, 0,14 g massa removida de Carbono Orgânico Total (COT) / massa consumida de O3 e 0,43 g/g para a Demanda Química de Oxigênio (DQO). Quanto ao foto-Fenton, averiguou-se o máximo de 74% remoção de COT e 65% remoção DQO para a razão molar [H2O2]/[Fe2+] igual a 2. Também se notou formação de sólidos sedimentáveis neste processo aplicado ao lixiviado bruto. O pré-tratamento por air-stripping não promoveu incremento na remoção de matéria orgânica. As concentrações de NAT, alcalinidade, SDT (cloretos) se mantiveram elevadas após a aplicação dos POA. Ocorreu formação de nitrato em todos os tratamentos. O uso do NMOC foi adequado e demonstrou ocorrência de oxidação nos processos. A quantificação do ácido oxálico formado após a aplicação dos POAs não foi apropriada nesta pesquisa. / The landfill leachate is a major waste produced by the landfill and its constitution complex and highly polluting motivate research in order to adapt their disposal on the environment. In this context, the advanced oxidation processes stand out as a pretreatment, in order to remove or decrease the recalcitrance of the leachate. In this work we used the photo-Fenton AOPs, ozone and ozone combined with hydrogen peroxide. We evaluated the effect of pretreatment for air-stripping, the variation in the production of ozone 80 and 100%, the best dose of hydrogen peroxide equal to 20, 40 and 80% of the dose of 6g O3/ L used in the treatments with ozone, the removal of organic matter, total ammonia nitrogen, alkalinity, dissolved solids (chlorides), production of nitrite and nitrate, best molar ratio [H2O2]/[Fe2+] to the contact time of 80 min in the photo-Fenton, average number of carbon oxidation use and the measurement of oxalic acid formed after application of the AOPs. The AOP O3/H2O2 (1.2g H2O2/L and O3 production by 80%) had the highest removal of organic matter, 0.14 g of TOC removed mass/ mass consumed O3 and 0.43 g/g for COD. As for the photo-Fenton, it was found a maximum of 74% removal of TOC and 65% for COD removal molar ratio [H2O2]/[Fe2+] equal to 2. It was also noted the formation of settle able solids in the process applied to the raw leachate. Pretreatment by air-stripping did not promote an increase in organic matter removal. Total ammonia nitrogen concentrations, alkalinity, dissolved solids (chlorides) remained high after application of the AOP, indicating possible oxidant demand. For nitrate formation occurred in all treatments, while only the photo-Fenton was no formation of nitrite. The use of average number of carbon oxidation was adequate and showed occurrence of oxidation processes. The quantification of oxalic acid formed after the application of AOPs was not appropriate in this research.

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