Bibliografías temáticas / Refractory nitrogen and COD

Literatura académica sobre el tema "Refractory nitrogen and COD"

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Publicado: 20 de abril de 2024

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Artículos de revistas sobre el tema "Refractory nitrogen and COD"

1

Song, Yu Lin, Masanobu Uchida y Sotaro Higuchi. "Effects of Incinerator Exhaust Gas Treatment Agents and Fly Ash Processing Chelates on MSW Landfill Management". Applied Mechanics and Materials 768 (junio de 2015): 233–39. http://dx.doi.org/10.4028/www.scientific.net/amm.768.233.

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Lime used to treat flue gas from incinerators and organic chelating agents used to remove heavy metals from fly ash create a highly saline and alkaline environment at landfill sites, causing nitrification inhibition that hampers nitrogen treatment and generating refractory COD in the processes of organic stabilization by microbes and leachate treatment. The authors analyzed organic chelating agents and fly ash treated with the chelating agents, and monitored leachate from lysimeters, or simulated landfills. The results showed that organic chelating agents acted as nitrification inhibitors, and that higher water levels in landfill layers resulted in higher concentrations of thiourea and refractory COD, which are chelating compounds, hindering leachate treatment.
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Deng, Miao, Keming Wu, Tao Yang, Deyou Yu, Gaojie Liu, Shuai Gong, Dongni Sun y Michal Petru. "Construction of Novel Electro-Fenton Systems by Magnetically Decorating Zero-Valent Iron onto RuO2-IrO2/Ti Electrode for Highly Efficient Pharmaceutical Wastewater Treatment". Water 14, n.º 7 (26 de marzo de 2022): 1044. http://dx.doi.org/10.3390/w14071044.

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The Electro-Fenton (E-Fenton) technique has shown great potential in wastewater treatment, while the sustainable and continuing supply of Fe2+ remains challenging. Herein, we demonstrate the construction of a novel E-Fenton system by magnetically decorating zero-valent iron (ZVI) onto a RuO2-IrO2/Ti (ZVI-RuO2-IrO2/Ti) electrode for high-efficient treatment of pharmaceutical wastewater, which is considerably refractory and harmful to conventional biological processes. By using ZVI as a durable source of Fe(II) irons, 78.69% of COD and 76.40% of TOC may be rapidly removed by the developed ZVI-RuO2-IrO2/Ti electrode, while the ZVI-RuO2-IrO2/Ti electrode using ZVI only reduces 35.64% of COD under optimized conditions at initial COD and TOC values of 5500 mg/L and 4300 mg/L, respectively. Moreover, the increase in BOD5/COD from 0.21 to 0.52 highlights the enhanced biodegradability of the treated effluent. The analysis of a simultaneously formed precipitation on electrodes suggests that the coagulation process dominated by Fe3+/Fe2+ also plays a non-negligible role in pharmaceutical wastewater treatment. In addition, the monitoring of the evolution of nitrogen elements and the formation of by-products in the E-Fenton process verifies its great capacity toward those organic pollutants found in pharmaceutical wastewater. Our study offers a practical solution for enhancing the performance of E-Fenton systems, and effectively treating refractory pharmaceutical wastewater.
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3

Wang, C. R., Z. F. Hou, M. R. Zhang, J. Qi y J. Wang. "Electrochemical Oxidation Using BDD Anodes Combined with Biological Aerated Filter for Biotreated Coking Wastewater Treatment". Journal of Chemistry 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/201350.

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Coking wastewater is characterized by poor biodegradability and high microorganism toxicity. Thus, it is difficult to meet Grade I of Integrated Wastewater Discharge Standard of China by biological treatment technology; specifically, COD cannot meet above standard due to containing refractory organics. A novel coupling reactor, electrochemical oxidation using BDD anodes and biological aerated filter (BAF), has been developed for carbon and nitrogen removal from biotreated coking wastewater, focusing on COD, BOD5,NH4+-N, andNO3--N removal on operation over 90 days with average effluent value of 91.3, 9.73, 0.62, and 13.34 mgL−1, respectively. Average value of BOD5/COD and BOD5/NO3--N was enhanced from 0.05 to 0.27 and from 0.45 to 1.21 by electrochemical oxidation, respectively, with average energy consumption of 67.9 kWh kg−1COD. In addition, the refractory organics also were evidently mineralized in the unit based on the data of the three-dimensional fluorescence spectra. Meanwhile, its effluent provided excellent substrate for biological denitrification in BAF. At hydraulic retention time (HRT) of 13.08 h, about 12 mgL−1 NO3--N was depleted through denitrification, and it mainly occurred at top of 0.25 m height of BAF. Therefore, it is feasible to apply the coupling reactor for biotreated coking wastewater treatment and achieve desirable effluent quality.
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Wang, Jian, Cong Du, Feng Qian, Yonghui Song y Liancheng Xiang. "Enhanced Treatment of Pharmaceutical Wastewater by an Improved A2/O Process with Ozone Mixed Municipal Wastewater". Water 12, n.º 10 (5 de octubre de 2020): 2771. http://dx.doi.org/10.3390/w12102771.

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A pilot-scale experiment is carried out for treating mixed wastewater containing pharmaceutical wastewater (PW) and domestic wastewater (DW), by a process that is a combination of hydrolysis acidification-ozone-modified anaerobic–anoxic–aerobic-ozone (A2/O) (pre-ozone) or hydrolysis acidification-modified A2/O-ozone (post-ozone). The effects of different mixing ratios of PW and DW and pre-ozone treatment or post-ozone treatment on the removal of nitrogen and phosphorus and chemical oxygen demand (COD) are compared and studied. The optimal ratio of PW in mixing wastewater is 30%, which has the optimal COD removal efficiency and minimum biotoxicity to biological treatment. The pre-ozone treatment shows more advantages in removing nitrogen and phosphate but the post-ozone treatment shows more advantages in COD removal. Analysis of dissolved organic matter (DOM) demonstrates that post-ozone treatment has a more significant effect on the removal of fulvic acid and humic acid than the effect from the pre-ozone treatment, so the COD removal is better. Overall DOM degradation efficiency by post-ozone treatment is 55%, which is much higher than the pre-ozone treatment efficiency of 38%. Microbial community analysis reveals that the genus Thauera and the genus Parasegetibacter take great responsibility for the degradation of phenolics in this process. All the results show that the post-ozone treatment is more efficient for the mixed wastewater treatment in refractory organics removal.
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Hosomi, Masaaki, Inamori Yuhei, Kazuo Matsushige y Ryuichi Sudo. "Denitrification of Landfill Leachate by the Modified Rotating Biological Contactor (RBC)". Water Science and Technology 23, n.º 7-9 (1 de abril de 1991): 1477–85. http://dx.doi.org/10.2166/wst.1991.0600.

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In order to remove high-strength nitrogen and organics in landfill leachate simultaneously, the modified RBC which was combined with the standard RBC and the anaerobic biofilter was proposed. The treatability for actual landfill leachate of the standard RBC and the modified RBC was evaluated. The capability of COD removal in the modified RBC is much greater than that in the standard RBC, although both RBCs showed a BOD removal rate of more than 95%. This suggested that the combination method of aerobic and anaerobic treatment was effective in reducing refractory organic compounds. The nitrogen removal in the modified RBC was about 90% compared to 50% in Che standard RBC. The modified RBC had the advantage of nitrogen removal because nitrification and denitrification proceeded efficiently, even if a carbon source was not added. The performance of the modified RBC was superior to that of the standard RBC in both BOD surface loading and BOD volumetric loading.
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6

Zhang, Dejin, Weicheng Han, Yujun Zhou, Cheng Yan, Dianzhan Wang, Jianru Liang y Lixiang Zhou. "Feasibility of Bio–Coagulation Dewatering Followed by Bio–Oxidation Process for Treating Swine Wastewater". International Journal of Environmental Research and Public Health 20, n.º 4 (8 de febrero de 2023): 2990. http://dx.doi.org/10.3390/ijerph20042990.

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The unsatisfactory performance of the conventional swine wastewater treatment is drawing increasing attention due to the large amount of refractory chemical oxygen demand (COD), nitrogen, and phosphorus attached to the suspended solids (SS). In this study, for the first time, a novel process based on bio–coagulation dewatering followed by a bio–oxidation (BDBO) system was developed to treat swine wastewater containing high–strength SS, COD, TN, and TP. Firstly, after the bio–coagulation process, the removal efficiencies of SS, COD, NH3–N, and TP reached as high as 99.94%, 98.09%, 61.19%, and 99.92%, respectively. Secondly, the filtrate of the bio–coagulation dewatering process was introduced into the subsequent bio–oxidation process, in which the residual COD and NH3–N were further biodegraded in a sequence batch reactor. In addition, the dewatering performance of the concentrated swine slurry was substantially improved, with the specific resistance to filtration decreasing from 17.0 × 1012 to 0.3 × 1012 m/kg. Moreover, the concentrated swine slurry was pressed and filtered into a semi–dry cake after pilot–scale bio–coagulation dewatering treatment. Finally, the concentrations of COD and NH3–N in the effluent after the BDBO process, ranging between 150–170 mg/L and 75–90 mg/L, met the relevant discharge standard. Compared to traditional treatments, the BDBO system has excellent large–scale potential for improving the treatment efficiency, shortening the operation period, and reducing the processing costs, and is emerging as a cost–effective alternative for the treatment of wastewater containing high concentrations of SS, COD, TN, and TP.
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Martínez-Cruz, Alfredo y María Neftalí Rojas-Valencia. "Assessment of Phytotoxicity in Untreated and Electrochemically Treated Leachates through the Analysis of Early Seed Growth and Inductively Coupled Plasma-Optical Emission Spectroscopy Characterization". Horticulturae 10, n.º 1 (9 de enero de 2024): 67. http://dx.doi.org/10.3390/horticulturae10010067.

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The treatment of stabilized leachates with high refractory organic matter content, which are over 10 years old, presents a challenge. This study explored the potential of electro-coagulation (EC) and electro-oxidation (EO) treatment systems to address this issue. The objective of this study was to investigate the phytotoxicity of the proposed treatment system on seed growth and examine possible relationships between phytotoxicity results and the characterization of leachates, effluents, soil, and radicles. Phytotoxicity tests were conducted on seeds of Lactuca sativa, Cucumis sativus, and Phaseolus vulgaris, using Inductively Coupled Plasma-Optical analysis. The evolution of organic matter was monitored by fractionating the chemical oxygen demand (COD) and humic substances. The biodegradability index increased from 0.094 in raw leachate to 0.26 and 0.48 with EC and EO, respectively. Removal rates of 82%, 86%, 99%, and 81% were achieved for COD, dissolved organic carbon, color, and ammoniacal nitrogen, respectively. The biodegradable COD increased from 26% in raw leachate to 39% in the EC process and 58% in the EO process effluent. The proposed treatment system successfully broke the aromatic structures of the humic substances present in the raw leachate, thereby increasing the content of biodegradable material. Phytotoxicity tests revealed that the proposed treatment system significantly reduced the phytotoxicity of the generated effluents.
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Wang, Jiaqi, Zhengguang He, Yuzhong Wang y Manjing Lu. "Electrochemical/Peroxymonosulfate/NrGO-MnFe2O4 for Advanced Treatment of Landfill Leachate Nanofiltration Concentrate". Water 13, n.º 4 (4 de febrero de 2021): 413. http://dx.doi.org/10.3390/w13040413.

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A simple one-pot method was used to successfully embed manganese ferrite (MnFe2O4) nanoparticles on the nitrogen-doped reduced graphene oxide matrix (NrGO), which was used to activate peroxymonosulfate to treat the landfill leachate nanofiltration concentration (LLNC) with electrochemical enhancement. NrGO-MnFe2O4 and rGO-MnFe2O4 were characterized by various means. This indicates that nitrogen-doped could induce more graphene oxide (GO) spall and reduction to produce more active centers, and was favorable for uniformly loading MnFe2O4 particles. The comparison between electrochemical/peroxymonosulfate/NrGO-MnFe2O4 (EC/PMS/NrGO-MnFe2O4) system and different catalytic systems shows that electrochemical reaction, NrGO and MnFe2O4 can produce synergies, and the chemical oxygen demand (COD) removal rate of LLNC can reach 72.89% under the optimal conditions. The three-dimensional (3D-EEM) fluorescence spectrum shows that the system has a strong treatment effect on the macromolecules with intense fluorescence emission in LLNC, such as humic acid, and degrades into substances with weak or no fluorescence characteristics. Gas chromatography-mass spectrometry (GC-MS) indicates that the complex structure of refractory organic compounds can be simplified, while the simple small molecular organic compounds can be directly mineralized. The mechanism of catalytic degradation of the system was preliminarily discussed by the free radical quenching experiment. Therefore, the EC/PMS/NrGO-MnFe2O4 system has significant application potential in the treatment of refractory wastewater.
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Graja, S. y P. A. Wilderer. "Characterization and treatment of the liquid effluents from the anaerobic digestion of biogenic solid waste". Water Science and Technology 43, n.º 3 (1 de febrero de 2001): 265–74. http://dx.doi.org/10.2166/wst.2001.0146.

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The process wastewater generated by the fermentation of biogenic fractions of solid waste (biowaste) is characterized by very specific composition features, which sets it apart from the well known categories of wastewater. Up to now, there is a definite lack of practical experience and know-how in the treatment of those effluents. In view of the increasingly wide acceptance awarded to the fermentation process, it appears necessary, however, to include the treatment of the generated wastewater in the overall process and to grant it the same priority as the fermentation step. In this study, pilot-scale experiments were conducted over 200 days in a sequencing batch reactor (SBR), with the wastewater from a full-scale Bavarian biowaste digestion plant. Characterization of the influent implementing molecular size distribution studies showed that 97% of the components were either in particular form or <1 kD. The main classes of compounds present in these fractions have been identified. The treatment objectives of the SBR plant were carbon and nitrogen removal. Soluble COD removal efficiencies were comprised between 40 and 60%, yielding a residual, refractory COD concentration of about 2000 mg/L in the effluent. Ammonium removal efficiencies averaged 96% and denitrification occurred with the addition of acetic acid or pretreated biowaste as a carbon source. Pretreated biowaste also showed synergetic effects as a co-substrate for COD removal.
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Capodici, M., D. Di Trapani y G. Viviani. "Co-treatment of landfill leachate in laboratory-scale sequencing batch reactors: analysis of system performance and biomass activity by means of respirometric techniques". Water Science and Technology 69, n.º 6 (16 de enero de 2014): 1267–74. http://dx.doi.org/10.2166/wst.2014.005.

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Aged or mature leachate, produced by old landfills, can be very refractory; for this reason mature leachate is difficult to treat alone, but it can be co-treated with sewage or domestic wastewater. The aim of the study was to investigate the feasibility of leachate co-treatment with synthetic wastewater, in terms of process performance and biomass activity, by means of respirometric techniques. Two sequencing batch reactors (SBRs), named SBR1 and SBR2, were fed with synthetic wastewater and two different percentages of landfill leachate (respectively 10% and 50% v v−1 in SBR1 and SBR2). The results showed good chemical oxygen demand (COD) removal efficiency for both reactors, with average COD removals equal to 91.64 and 89.04% respectively for SBR1 and SBR2. Furthermore, both SBRs showed good ammonia-nitrogen (AN) removal efficiencies, higher than 60%, thus confirming the feasibility of leachate co-treatment with a readily biodegradable wastewater. Significant respiration rates were obtained for the heterotrophic population (average values of maximum oxygen uptake rate equal to 37.30 and 56.68 mg O2 L−1 h−1 respectively for SBR1 and SBR2), thus suggesting the feasibility of leachate co-treatment with synthetic wastewater.
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Tesis sobre el tema "Refractory nitrogen and COD"

1

Faixo, Sylvain. "Caractérisation et oxydation de composés organiques réfractaires issus du traitement thermique de boues d’épuration". Electronic Thesis or Diss., Toulouse, INSA, 2023. http://www.theses.fr/2023ISAT0059.

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Le traitement des boues générées dans les stations d’épuration représente un enjeu majeur d’optimisation globale énergétique et de flux de matières. Parmi les procédés émergents, les traitements thermiques de boues peuvent conduire à divers avantages : production de méthane plus élevée en digestion anaérobie, meilleure déshydratabilité en centrifugation ou hygiénisation des boues. Ils produisent cependant des composés bioréfractaires au travers des réactions de Maillard. Ces composés appelés mélanoïdines sont des polymères issus de processus de chimie combinatoire. Ils sont de poids moléculaires élevés, très insaturés, azotés et de structures très variées. Leur caractère bioréfractaire et soluble conduit à une absence de leur dégradation dans la filière eau de la station d’épuration et une augmentation significative de la DCO et du NTK en sortie.A partir de ces considérations, les questions auxquelles la thèse devait répondre sont les suivantes :- Comment quantifier et qualifier les composés réfractaires générés par les procédés thermiques ?- Comment dégrader ou mieux rendre biodégradables les composés réfractaires générés par les traitements thermiques ?Dans la première partie de la thèse, une méthode analytique a été développée pour caractériser les mélanoïdines. La méthode s’appuie sur une analyse par chromatographie à exclusion stérique (UPLC-SEC) avec détection par absorbance UV et fluorescence. Le couplage des résultats obtenus avec du traitement de données statistiques par analyse en composante principale et réseau de neurones mène à une approche innovante de la caractérisation de ces composés.Après validation, la méthode a montré sa capacité de différenciation des composés réfractaires entre eux et par rapport à des composés biodégradables pour des surnageants de boues de deux stations (110000 et 950000 EH) traitées thermiquement. Il a ainsi été montré que les boues biologiques produisent jusqu’à 2 fois plus de composés réfractaires que des boues primaires lors d’un traitement thermique. De plus, la structure des composés réfractaires formés dépend de la température et de la station d’origine des boues.Dans la deuxième partie de la thèse, le traitement et/ou l’amélioration de la biodégradabilité des composés réfractaires issus du traitement thermique par ozonation ou électro-oxydation ont été étudiés.L’étude d’ozonation a été menée au travers d’un plan d’expérience qui a permis de quantifier et caractériser l’impact du pH et des concentrations en DCO bioréfractaire, biodégradable et en N-NH4+ sur la transformation des molécules réfractaires. Les résultats ont montré que l’ozonation améliore nettement la biodégradabilité mais les performances observées sont influencées par la valeur du pH et la concentration en DCO réfractaire : la dose d’ozone nécessaire peut varier d’un facteur 2 à 3 en fonction des valeurs de ces paramètres. Enfin, la méthode UPLC-SEC développée permet d’identifier les structures chimiques et catégories de molécules conduisant à la prédiction de la biodégradabilité des échantillons en cours d’ozonation.L’électro-oxydation est une technologie encore peu déployée à échelle industrielle. Sur électrode en Diamant Dopé au Bore (DDB) dans un premier temps, le traitement de nos matrices par électro-oxydation montre qu’une minéralisation totale de la DCO et azote est possible. Par la suite d’autres essais ont été menés avec différents matériaux d’électrode et ont montré des résultats encourageants.Les deux technologies d’oxydation présentent donc des potentiels d’abattement de DCO et d’azote organique supérieurs à 70%, réduisant nettement les retours de composés réfractaires en tête de station d’épuration et permettant à celle-ci de respecter les normes en vigueurs.Dans une troisième partie de la thèse, une discussion analyse les avantages et inconvénients des technologies, montre des perspectives intéressantes à explorer pour approfondir les connaissances développées dans la thèse
The treatment of sludge produced by wastewater treatment plants (WWTP) represents a major challenge for the optimization of energy consumption and material flows. Among emerging processes, thermal treatments have many interests: increased methane production in anaerobic digestion, improved dewaterability by centrifugation and hygienization of sludges. However, they produce biorefractory organic compounds, also called melanoidins, through Maillard reactions. Those very diversified compounds are characterized by a high molecular weight, a polymeric and unsaturated structure, and a high nitrogen content. Their refractoriness prevents their biodegradation in common WWTP biological processes, leading to an increase of COD and TKN in the plant discharge.This thesis aimed to answer two main questions:- How to quantify and qualify biorefractory compounds formed by thermal processes?- How to degrade or to enhance the biodegradability of biorefractory compounds formed by thermal processes?First, an analytical method has been developed to characterize melanoidins, based on size exclusion liquid chromatography with UV and fluorescence detection (UPLC-SEC-UV-Fluo). Statistical treatment of the data by artificial neural network and principal component analysis led to an innovative characterization of melanoidins.Centrates of thermaly treated sludge from two WWTP (110,000 and 950,000p.e.) were studied. The method displayed a good ability to differentiate refractory compounds from each other and from biodegradable compounds.Our study exhibited that biological sludge produces twice as much refractory compounds than primary sludge. Moreover, the structure of refractory compound is linked to the process’ temperature and the sludge’s origin from, but it does not depend on the type of sludge thermally treated.Then, the degradation or biodegradability enhancement of refractory compounds by both ozonation and electro-oxidation was investigated.The ozonation was studied through an experimental plan to evaluate the impact of pH and concentrations of refractory COD, biodegradable COD and N-NH4+, on refractory molecules. Our results showed that ozonation can increase the biodegradability; its performances are influenced by pH and concentration of refractory COD. Optimal conditions can reduce the dose of ozone needed by two to three times. The UPLC-SEC-UV/Fluo method was then used to identify the chemical structures and the parameters predicting the biodegradability of refractory compounds during ozonation.The feasibility of electro-oxidation of refractory compounds was first assessed with a boron doped diamond anode. As a result, a complete mineralization was achieved for both organic nitrogen and COD. Therefore, active anodes were tested and highlighted a biodegradability enhancement when adding chlorine as electrolyte.Both technologies demonstrated up to 70% of refractory COD and organic nitrogen removal, decreasing substantially their recycling to the head of the plant.In the last part, the whole UPLC-SEC-UV/Fluo characterization method has been discussed in its potential and with respect to the literature. Finally, the benefits and possible drawbacks of each oxidation technology and their implementation at industrial scale were discussed
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2

楊龍元 y Lung-yuen Christopher Yeong. "Removal of wastewater cod and nitrogen using fibrous packing media". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1991. http://hub.hku.hk/bib/B31210636.

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Yeong, Lung-yuen Christopher. "Removal of wastewater cod and nitrogen using fibrous packing media /". [Hong Kong : University of Hong Kong], 1991. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13193429.

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au, L. Hughes@murdoch edu y Leonie Hughes. "Multistage and multiple biomass approaches to efficient biological nitrogen removal using biofilm cultures". Murdoch University, 2008. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20080523.134154.

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Nitrogen removal from wastewater is important for the revention of significant health and environmental impacts such as eutrophication. Nitrogen removal is achieved by the combined action of nitrification and denitrification. Nitrification is performed by autotrophic, slow growing microorganisms that require oxygen and are inhibited in the presence of denitrifiers when oxygen and COD are available due to competition for oxygen. Denitrification however, performed by relatively fast growing heterotrophic bacteria, is inhibited by oxygen and requires COD. This implies that nitrification and denitrification are mutually exclusive. The supply of oxygen to a fresh wastewater, high in ammonia and COD, causes waste of both oxygen and COD. Conservation of COD is therefore critical to efficient wastewater treatment. The approach investigated in this study to achieve complete nitrogen removal was to physically separate the nitrification and denitrification biomasses into separate bioreactors, supplying each with appropriate conditions for growth and activity. A storage driven denitrification sequencing batch biofilm reactor (SDDR) was established which exhibited a high level of COD storage (up to 80% of influent COD) as poly-B-hydroxybutyrate capable of removing >99% of nitrogen from wastewaters with a C/N ratio of 4.7 kg COD/kg N–NO3 –. The SDDR was combined in sequential operation with a nitrification reactor to achieve complete nitrogen removal. The multiple stage, multiple biomass reactor was operated in sequence, with Phase 1 - COD storage in the storage driven denitrification biofilm; Phase 2 - ammonia oxidation in the nitrification reactor; and Phase 3 - nitrate reduction using the stored COD in the storage driven denitrification reactor. The overall rate of nitrogen removal observed was up to 1.1 mmole NH3 L–1 h–1 and >99% of nitrogen could be removed from wastewaters with a low C/N ratio of 3.9 kg COD/kg N–NH3. The multiple stage, multiple biomass system was limited in overall nitrogen removal the reduction in pH caused by nitrification. A parallel nitrification-denitrificatio (PND) reactor was developed in response to the pH control issue. The PND reactor was operated with Phase 1 – COD storage in the storage driven denitrification biofilm and Phase 2 – simultaneous circulation of reactor liquor between the denitrification and nitrification biofilms to achieve complete nitrogen removal and transfer of protons. The PND reactor performed competitively with the multistage reactor (removal of >99% nitrogen from wastewaters with feed ratios of 3.4 kg COD/kg N–NH3) without the need for addition of buffering material to oderate the pH.
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Copp, John B. "COD balances in biological nutrient (nitrogen and phosphorus) removal activated sludge systems". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0022/NQ50987.pdf.

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Copp, John B. "COD balances in biological nutrient (nitrogen and phosphorus) removal activated sludge systems /". *McMaster only, 1998.

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7

Lettie, Lucia. "REMOVAL OF REFRACTORY TKN FROM AN EFFLUENT WASTEWATER USING SODIUM FERRATE". Master's thesis, University of Central Florida, 2006. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4326.

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This research addresses refractory forms of nitrogen that, even with advanced biological nitrification-denitrification systems are not removed completely from domestic wastewater. TKN (Total Kjeldahl Nitrogen), ammonia plus organic nitrogen, is one of the forms to measure the levels of nitrogen present in effluent wastewaters. Ferrate, a strong oxidant, was used for the treatment of these nitrogen forms with the objective of producing nitrogen compounds that can be removed by subsequent biological processes. Bench-scale experiments were performed on effluent samples taken prior to chlorination from an Orlando, FL wastewater treatment facility, using a biological nutrient removal process. The samples were treated with doses of ferrate ranging from 1 to 50 mg/L as FeO4–2 under unbuffered conditions. TKN removal as high as 70% and COD removal greater than 55% was observed. The TSS production after ferrate treatment was in a range of 12 to 200 mg/L for doses between 10 and 50 mg/L FeO4-2. After an optimum dose of ferrate was determined, three bench-scale reactors were operated under anoxic conditions for 10 to 12 days, two as duplicates containing the treated effluent and one as a control with untreated sample. Two different doses of ferrate were used as optimum dose for these experiments, 10 and 25 mg/L as FeO4-2. The purpose of these reactors was to determine the potential for biological removal of remaining nitrogen after ferrate oxidation of refractory nitrogen. Treated and raw samples were analyzed for Total Kjeldahl Nitrogen (TKN) (filtered and unfiltered), chemical oxygen demand (COD) (filtered and unfiltered), total suspended solids (TSS), nitrate (NO3-N), nitrite (NO2-N), and heterotrophic plate count (HPC). As a result, more than 70% of the soluble TKN was removed by chemical and biological oxidation for a sample treated with a dose of 25 mg/L FeO4-2, and less than 50% when treated with 10 mg/L FeO4-2. For the control samples run parallel to the ferrate treated samples, a maximum of 48% of soluble TKN and a minimum of 12% was removed. A three-log increase was observed in heterotrophic bacteria numbers for both doses during the operation of the reactors. Sodium ferrate was found to be an effective oxidant that can enhance the biodegradability of recalcitrant TKN present in municipal wastewaters. As mentioned before this research was develop using batch reactor units at bench-scale, therefore it is recommended to follow the investigation of the biodegradability of recalcitrant TKN of a ferrate treated sample under continuous flow conditions so that results can be extrapolated to a full-scale treatment facility.
M.S.Env.E.
Department of Civil and Environmental Engineering
Engineering and Computer Science
Environmental Engineering
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Stenström, Ylva. "Phosphorus and Nitrogen Removalin Modified Biochar Filters". Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-321915.

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Onsite wastewater treatment systems in Sweden are getting old and many of them lack sufficient phosphorus, nitrogen and organic carbon reduction. Biochar is a material that has been suggested as an alternative to the common sand or soil used in onsite wastewater treatment systems. The objective of this study was to compare the phosphorus removal capacity between three different modified biochars and one untreated biochar in a batch adsorption and column filter experiment. The modifications included impregnation of ferric chloride (FeCl3), calcium oxide (CaO) and untreated biochar mixed with the commercial phosphorus removal product Polonite. To further study nitrogen removal a filter with one vertical unsaturated section followed by one saturated horizontal flow section was installed. The batch adsorption experiment showed that CaO impregnated biochar had the highest phosphorus adsorption, i.e. of 0.30 ± 0.03 mg/g in a 3.3 mg/L phosphorus solution. However, the maximum adsorption capacity was calculated to be higher for the FeCl3 impregnated biochar (3.21 ± 0.01 mg/g) than the other biochar types. The pseudo 2nd order kinetic model proved better fit than the pseudo 1st order model for all biochars which suggest that chemical adsorption was important. Phosphorus adsorption to the untreated and FeCl3 impregnated biochar fitted the Langmuir adsorption isotherm model best. This indicates that the adsorption can be modeled as a homogenous monolayer process. The CaO impregnated and Polonite mixed biochars fitted the Freundlich adsorption model best which is an indicative of heterogenic adsorption. CaO and FeCl3 impregnated biochars had the highest total phosphorus (Tot-P) reduction of 90 ± 8 % and 92 ± 4 % respectively. The Polonite mixed biochar had a Tot-P reduction of 65 ± 14 % and the untreated biochar had a reduction of 43 ± 24 %. However, the effluent of the CaO impregnated biochar filter acquired a red-brown tint and a precipitation that might be an indication of incomplete impregnation of the biochar. The FeCl3 effluent had a very low pH. This can be a problem if the material is to be used in full-scale treatment system together with biological treatment for nitrogen that require a higher pH. The nitrogen removal filter showed a total nitrogen removal of 62 ± 16 % which is high compared to conventional onsite wastewater treatment systems. Batch adsorption and filter experiment confirms impregnated biochar as a promising replacement or addition to onsite wastewater treatment systems for phosphorus removal. However the removal of organic carbon (as chemical oxygen demand COD) in the filters was lower than expected and further investigation of organic carbon removal needs to be studied to see if these four biochars are suitable in real onsite wastewater treatment systems.
Många av Sveriges små avloppssystem är gamla och saknar tillräcklig rening av fosfor, kväve och organiskt material. Följden är förorenat grundvatten samt övergödning i hav, sjöar och vattendrag. Lösningar för att förbättra fosfor- och kvävereningen finns på marknaden men många har visat brister i rening och robusthet. Biokol är ett material som har föreslagits som ersättare till jord eller sand i mark och infiltrationsbäddar. Denna studie syftade till att i skak- och kolonnfilterexperiment jämföra fosforreduktion mellan tre modifierade biokol och ett obehandlat biokol. Modifieringen av biokolet innebar impregnering med järnklorid (FeCl3), kalciumoxid (CaO) samt blandning med Polonite som är en kommersiell produkt för fosforrening. För att undersöka förbättring av kväverening installerades även ett filter med obehandlat biokol där en vertikal aerob modul kombinerades med en efterföljande horisontell anaerob modul. Skakstudien där biokolen skakades i 3.3 mg/L fosforlösning visade att adsorptionen var högst i det CaO-impregnerade biokolet, 0.3 ± 0.03 mg/g. Den maximala potentiella fosforadsorptionen beräknades dock vara högst för biokolet som impregnerats med FeCl3, 3.21 ± 0.01 mg/g. Skakförsöket visade också att fosforadsorptionen var främst kemisk då adsorptionen passade bättre med pseudo andra ordningens modell än pseudo första. Adsorption av fosfor på obehandlat biokol och FeCl3 impregnerat biokol modellerades bäst med Langmuir modellen, vilket tyder på en homogen adsorption. Det Polonite-blandade biokolet och CaO-impregnerade biokolet modellerades bäst med Freundlich modellen vilket är en indikation på en heterogen adsorptionsprocess. Biokol impregnerat med CaO och FeCl3 gav de högsta totalfosforreduktionerna på 90 ± 8 % respektive 92 ± 4 %. Biokolet som var blandat med Polonite hade en reduktion på 65 ± 14 % och det obehandlade biokolet 43 ± 24 %. Ett problem med filtratet från CaO-filtret var att det fick en rödbrun färg samt en fällning vilket kan ha berott på ofullständig pyrolysering och impregnering. Filtratet från det FeCl3 impregnerade biokolet hade mycket lågt pH vilket kan vara problematiskt om mikrobiologisk tillväxt i filtret för rening av kväve och organiskt material vill uppnås. Filtret för kväverening gav en total kvävereduktion på 62 ± 16 % vilket är högre än kommersiella system. Resultaten från skak och filterstudien visade på att impregnerade biokol kan ge en förbättrad fosforrening om de skulle användas i små avloppssystem. Rening av organiskt material, kemisk syreförbrukning (COD), var dock låg i alla filter och behöver studeras ytterligare för att avgöra om dessa biokol är lämpliga för småskalig avloppsvattenrening.
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Chadwick, Terry D. "Nitrogen excretion and expression of urea cycle enzymes during early life stages of Atlantic cod and rainbow trout". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ35873.pdf.

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Vu, Thi Nguyet, Van Tua Tran, Dinh Kim Dang, Thi Kim Anh Bui y Hai Yen Vu. "Application of ecological technology for removal of COD, nitrogen and phosphorus from piggery wastewater after biogas production technology". Technische Universität Dresden, 2016. https://tud.qucosa.de/id/qucosa%3A32627.

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Despite a positive contribution to economic – social development, the growth of piggeries has caused heavily environmental pollution. Currently, treated wastewater of pig farms unfortunately does not meet the national discharge standards yet. This paper presents some research results on the removing COD, nitrogen and phosphorus in piggery wastewater after anaerobic (biogas) process at pilot scale by the combined system using Phragmites australis, Cyperus alternifolius, Vetiveria zizanioides and Eichhornia crassipes. The experimental results showed that the wastewater loading rate of 47.35 l/m2.day with initial concentrations of 203.24 mg COD/l, 111.94 mgTN/l and 13.61 mgTP/l gave removal efficiency of 71.66 %, 79.26 % and 69.65 %, respectively. Thus, the removed quantity of total nitrogen (TN) and total phosphorus (TP) was of 4201.35 mg TN/m2.day và 448.76mg TP/m2.day. The obtained results indicated that the flow wetland system, using Phragmites australis, Cyperus alternifolius, Vetiveria zizanioides and Eichhornia crassipes has a rather high COD, TN and TP removal efficiency with simple operation so that it could be feasible if applied for treating pig wastewater. However, the system should be functioned longer for taking data and for evaluating its stability.
Mặc dù có những đóng góp tích cực cho sự phát triển kinh tế - xã hội, việc phát triển chăn nuôi lợn đã gây ô nhiễm môi trường nghiêm trọng. Hiện nay, nước thải chăn nuôi lợn từ các cơ sở chăn nuôi sau xử lý vẫn chưa đáp ứng được các tiêu chuẩn thải của quốc gia và tiêu chuẩn ngành. Bài báo này trình bày kết quả nghiên cứu về khả năng loại bỏ COD, nitơ (N) và phôtpho (P) trong nước thải chăn nuôi lợn đã qua xử lý bằng hầm biogas của hệ thống phối hợp cây Sậy, Thủy Trúc, cỏ Vetiver và Bèo Tây ở qui mô pilot. Kết quả thực nghiệm ở tải lượng 47,35 l/m2.ngày, với COD, tổng nitơ (TN) và tổng phôtpho (TP) đầu vào trung bình là 203,24 mg/l, 111,94 mg/l và 13,61 mg/l, tương ứng, thì hiệu suất xử lý lần lượt là 71,66 %; 79,26 % và 69,65 %. Như vậy lượng TN và TP loại bỏ là 4201,35 mgN/m2.ngày và 448,76 mgP/m2.ngày. Kết quả nhận được cho thấy hệ thống sử dụng cây Sậy, Thủy Trúc, cỏ Vetiver và Bèo Tây có hiệu quả loại bỏ COD, TN và TP khá cao trong khi vận hành đơn giản nên có triển vọng áp dụng trong điều kiện thực tế để xử lý nước thải chăn nuôi lợn. Tuy nhiên để đánh giá tính ổn định, hệ thống cần được hoạt động với thời gian lâu dài hơn.
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Libros sobre el tema "Refractory nitrogen and COD"

1

Desimone, Leslie A. A nitrogen-rich septage-effluent plume in a glacial aquifer, Cape Cod, Massachusetts, February 1990 through December 1992. Marlborough, Mass: U.S. Dept. of the Interior, U.S. Geological Survey, 1995.

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Desimone, Leslie A. A nitrogen-rich septage-effluent plume in a glacial aquifer, Cape Cod, Massachusetts, February 1990 through December 1992. Marlborough, Mass: U.S. Dept. of the Interior, U.S. Geological Survey, 1995.

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Desimone, Leslie A. A nitrogen-rich septage-effluent plume in a glacial aquifer, Cape Cod, Massachusetts, February 1990 through December 1992. Marlborough, Mass: U.S. Dept. of the Interior, U.S. Geological Survey, 1995.

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Desimone, Leslie A. A nitrogen-rich septage-effluent plume in a glacial aquifer, Cape Cod, Massachusetts, February 1990 through December 1992. Washington: U.S. G.P.O., 1996.

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Desimone, Leslie A. A nitrogen-rich septage-effluent plume in a glacial aquifer, Cape Cod, Massachusetts, February 1990 through December 1992. Marlborough, Mass: U.S. Dept. of the Interior, U.S. Geological Survey, 1995.

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Desimone, Leslie A. A nitrogen-rich septage-effluent plume in a glacial aquifer, Cape Cod, Massachusetts, February 1990 through December 1992. Marlborough, Mass: U.S. Dept. of the Interior, U.S. Geological Survey, 1995.

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M, Barlow Paul, Howes Brian L, Massachusetts. Dept. of Environmental Protection. Office of Watershed Management y Geological Survey (U.S.), eds. A nitrogen-rich septage-effluent plume in a glacial aquifer, Cape Cod, Massachusetts, February 1990 through December 1992. Marlborough, Mass: U.S. Dept. of the Interior, U.S. Geological Survey, 1995.

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Desimone, Leslie A. A nitrogen-rich septage-effluent plume in a glacial aquifer, Cape Cod, Massachusetts, February 1990 through December 1992. Marlborough, Mass: U.S. Dept. of the Interior, U.S. Geological Survey, 1995.

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A nitrogen-rich septage-effluent plume in a glacial aquifer, Cape Cod, Massachusetts, February 1990 through December 1992. Marlborough, Mass: U.S. Dept. of the Interior, U.S. Geological Survey, 1995.

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Capítulos de libros sobre el tema "Refractory nitrogen and COD"

1

Tomashik, Vasyl. "Boron – Carbon – Nitrogen". En Refractory metal systems, 444–73. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-88053-0_19.

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Tomashik, Vasyl. "Carbon – Nitrogen – Silicon". En Refractory metal systems, 531–50. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-02700-0_34.

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Perrot, Pierre. "Carbon – Nitrogen – Uranium". En Refractory metal systems, 551–59. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-02700-0_35.

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Tomashik, Vasyl´. "Boron – Nitrogen – Titanium". En Refractory metal systems, 83–90. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-02700-0_7.

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Perrot, Pierre. "Iron – Nitrogen – Titanium". En Refractory metal systems, 287–98. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-00771-2_23.

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Tomashik, Vasyl, Tamara Velikanova, Mikhail Turchanin y Dmytro Pavlyuchkov. "Molybdenum – Nitrogen – Titanium". En Refractory metal systems, 339–49. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-00771-2_27.

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Tomashik, Vasyl. "Nitrogen - Oxygen - Silicon". En Refractory metal systems, 455–74. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-00771-2_38.

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Perrot, Pierre. "Nitrogen - Uranium - Zirconium". En Refractory metal systems, 475–79. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-00771-2_39.

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Liu, Hao y Zhi-kang Zhang. "Numerical Investigation of the Environment Capacity of COD, Inorganic Nitrogen and Phosphate in the Bohai Bay". En Communications in Computer and Information Science, 753–61. Singapore: Springer Singapore, 2017. http://dx.doi.org/10.1007/978-981-10-6364-0_74.

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Phu, Song Toan Pham. "Research on the Correlation Between Chlorophyll-a and Organic Matter BOD, COD, Phosphorus, and Total Nitrogen in Stagnant Lake Basins". En Sustainable Living with Environmental Risks, 177–91. Tokyo: Springer Japan, 2014. http://dx.doi.org/10.1007/978-4-431-54804-1_15.

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Actas de conferencias sobre el tema "Refractory nitrogen and COD"

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Wang, Yu-Lan y Shui-Li Yu. "Simultaneous COD, Nitrogen and Phosphate Removal in an Aerobic Granular Sludge Membrane Bioreactor". En 2009 3rd International Conference on Bioinformatics and Biomedical Engineering (iCBBE). IEEE, 2009. http://dx.doi.org/10.1109/icbbe.2009.5163402.

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Arzuov, M. A., B. I. Gaynullin y S. A. Ubaidullaev. "High-temperature fusion of nitrogen compounds at laser influence on refractory metals". En Seventh International Conference on Laser and Laser Information Technologies, editado por Vladislav Y. Panchenko y Vladimir S. Golubev. SPIE, 2002. http://dx.doi.org/10.1117/12.464132.

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Zhang, Cheng. "Numerical Modeling of Coal Gasification in an Entrained-Flow Gasifier". En ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-88481.

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The gasification technology has been applied in Integrated Gasification Combined Cycle (IGCC) plants for the production of power, and polygeneration plants for the production of industrial chemicals, fuels, hydrogen, and power. The major advantages of the gasification technology are its potential for feed-stock flexibility, product flexibility, and relative simple removal of harmful emissions of nitrogen oxides (NOx), sulfur oxides (SOx), and CO2. Entrained-flow gasifiers are the preferred gasifier design for future deployment due to their high carbon conversion, high efficiency and high syngas purity. Current entrained-flow gasifier designs still have serious problems such as injector failure, refractory failure, slag blockages, downstream fouling and poisoning, poor space efficiency, and lack of dynamic feedstock flexibility. To better understand the entrained-flow gasification process, we performed steady Reynolds-averaged Navier-Stokes (RANS) modeling of the laboratory-scale gasifier developed at Brigham Young University (BYU) using ANSYS Fluent. An Eulerian approach is used to describe the gas phase, and a Lagrangian approach is used to describe the particle phase. The interactions between the gas phase and particle phase is modeled using the particle-source-in-cell approach. Turbulence is modeled using the shear-stress transport (SST) k–ω model. Turbulent particle dispersion is taken into account by using the discrete random walk model. Devolatilization is modeled using a version of the chemical percolation devolatilization (CPD) model, and char consumption is described with a shrinking core model. Turbulent combustion in the gas phase is modeled using a finite-rate/eddy-dissipation model. Radiation is considered by solving the radiative transport equation with the discrete ordinates model. Second-order upwind scheme is used to solve all gas phase equations. First, to validate the flow solver, we performed numerical modeling of a non-reacting particle-laden bluff-body flow. For the non-reacting flow, the predicted mean velocities of the gas phase and the particle phase are in good agreement with the experimental data. Next, we performed numerical modeling of the gasification process in the BYU gasifier. The predicted profiles of the mole fractions of the major species (i.e. CO, CO2, H2, and H2O) along the centerline are in reasonable agreement with the experimental data. The predicted carbon conversion at the gasifier exit agrees with the experimental data. The predicted temperature at the gasifier exit agrees with the estimated value based on water-gas shift equilibrium considerations. The numerical model was further applied to study the effects of the equivalence ratio, particle size, and swirl on the gasification process.
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Hayami, Yuichi y Yuichi Hayami. "DECADAL SCALE VARIATION IN BOTTOM DO AND COD DYNAMICS IN THE INNER AREA OF ARIAKE SEA, JAPAN". En Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.31519/conferencearticle_5b1b939063c9c3.99016046.

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The dissolved oxygen, COD (Chemical Oxygen Demand) and DIN (Dissolved Inorganic Nitrogen) data for more than 30 years in the inner area of Ariake Sea, Japan were analyzed with a box model. The bottom water in this area easily became hypoxic from the 1970s to the early 90s associated with the increase in COD. There were minimal increases in terrestrial COD and nutrient loads in this period and there remained tidal flats over a widespread area. The increase in COD was caused by the increase in internal production (net ecosystem production in the sea). This would be due to the enhanced primary production induced by the increase in freshwater residence time and the decrease in bivalves grazing. The increase in freshwater residence time would have been caused by the decline of tidal amplitude mainly generated by the decrease of outer sea tidal amplitude. There would be a negative feedback control where hypoxia tends to progressively increase leading to declines in bivalve biomass which subsequently remove grazing pressure limiting primary production and on senescence of blooms of phytoplankton enhances hypoxia. The possibility of the influence of the Isahaya sea dike construction and how to improve the hypoxic conditions are also discussed.
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Hayami, Yuichi y Yuichi Hayami. "DECADAL SCALE VARIATION IN BOTTOM DO AND COD DYNAMICS IN THE INNER AREA OF ARIAKE SEA, JAPAN". En Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.21610/conferencearticle_58b431561360b.

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The dissolved oxygen, COD (Chemical Oxygen Demand) and DIN (Dissolved Inorganic Nitrogen) data for more than 30 years in the inner area of Ariake Sea, Japan were analyzed with a box model. The bottom water in this area easily became hypoxic from the 1970s to the early 90s associated with the increase in COD. There were minimal increases in terrestrial COD and nutrient loads in this period and there remained tidal flats over a widespread area. The increase in COD was caused by the increase in internal production (net ecosystem production in the sea). This would be due to the enhanced primary production induced by the increase in freshwater residence time and the decrease in bivalves grazing. The increase in freshwater residence time would have been caused by the decline of tidal amplitude mainly generated by the decrease of outer sea tidal amplitude. There would be a negative feedback control where hypoxia tends to progressively increase leading to declines in bivalve biomass which subsequently remove grazing pressure limiting primary production and on senescence of blooms of phytoplankton enhances hypoxia. The possibility of the influence of the Isahaya sea dike construction and how to improve the hypoxic conditions are also discussed.
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Takanashi, Reiko, Takehiko Kaneko, Riho Endo, Mikio Tosak, Tadashi Furuhata, Yumi Agata y Masayuki Goto. "Evaluation on the Drinking Water Quality Concerning Bacteria and Inorganic Nitrogen, PO4-P and COD Using Spring Water Samples". En The 4th World Congress on New Technologies. Avestia Publishing, 2018. http://dx.doi.org/10.11159/icepr18.127.

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Zhu Dongnan, Li Changyou, Sun Biao, Zhao Shengnan y Shi Xiaohong. "Temporal and spatial distribution of total nitrogen, total phosphorus and COD in the largest shallow lake of the upper Yellow River". En 2011 International Symposium on Water Resource and Environmental Protection (ISWREP). IEEE, 2011. http://dx.doi.org/10.1109/iswrep.2011.5893118.

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Bonchkovskyi, Andrii. "Assessment of anthropogenic pressure by nutrients and organic substances in the Sula river basin". En International Conference of Young Scientists on Meteorology, Hydrology and Environmental Monitoring. Ukrainian Hydrometeorological Institute, 2023. http://dx.doi.org/10.15407/icys-mhem.2023.029.

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The paper focuses on a man caused pressure in the Sula River with organic substances and nutrients which are the main factors affecting the water status. The Sula River is a left tributary of the Dnipro River flows into the Sulynska Bay of the Kremenchuk Reservoir. The water resources of the Sula River are used for drinking water supply, melioration, fish farming, etc. The Sulynska Bay is a spawning area for fish and the place of their largest commercial concentration. For a long time, the bay has been experiencing frequent cases of a critical decrease in dissolved O2, resulting in fish kills. Materials and methods of the study. The Electronic Services Portal of the State Agency of Water Resources of Ukraine (e-services.davr.gov.ua) as of 2021 was used to assess the contribution of studied compounds from point sources. The population was calculated based on the Atlas of the Administrative and Territorial Arrangement of Ukraine (2021). The pressure of nutrients and organic substances is calculated based on the person’s excretion coefficients, their removal by treatment facilities (Behrendt, Huber, Kornmilch et al., 2000; Osadcha, Luzovitska, Ukhan et al., 2022). Results and discussion. The total pressure from point sources is the sum of the urban population's contributions and industrial enterprises. Pollution with organic substances and nutrients from point sources is mainly associated with the wastewater discharge from settlements. There are 1141 settlements in the Sula basin, including 7 ones with a population ≥ 10 ths. people (36%), and 17 settlements with 2-10 ths. people (12%). The pressure of organic substances from the population connected to sewer systems was 512.9 t•year-1 for biochemical oxygen demand (BOD5) and 726.7 t•year-1 for chemical oxygen demand (COD). In terms of nutrients, the flow to surface waters was 162.3 t•year-1 for N and 56.1 t•year-1 for P. The largest organic pollution is caused by wastewater from the Ichnia municipal facility, while the nutrient pressure was caused by the corresponding enterprise in Pryluky. Annually, 111.2 t•year-1 of organic substances in terms of BOD5 and 133.1 t•year-1 in terms of COD is discharged into the Sula River basin with industrial wastewater. The pressure of nutrients supplied by industrial wastewater was 18.4 t•year-1 of Total nitrogen (TN) and 1.8 t•year-1 of Total Phosphorus (TP). The largest polluter in the Sula basin is Linovytskyi Sugar Plant “Krasnyi”, whose wastewater discharged ~ 67% of nutrients and up to 96% of organic substances from the total amount. Diffuse sources are dominated by pollution from the population without access to sewerage networks. To a greater extent, this applies to small settlements of ≤ 2000 people. This pressure is 2304 t•year-1 for BOD5 and 3917 t•year-1 for COD. Additionally, 224.3 tons of nitrogen and 31.5 tons of phosphorus are discharged annually into the Sula basin. The role of other diffuse sources, such as agriculture, land use patterns, etc., has a much smaller impact on the formation of surface water quality in the Sula River basin. Conclusions. The ecological status of surface waters in the Sula River basin depends on the quantitative parameters of anthropogenic pressure, which, according to BOD5, is 2928 t•year-1, COD – 4777 t•year-1. For nitrogen and phosphorus compounds, the obtained indicators in the context of the year reach 405 t•year-1 and 89 t•year-1. The peculiarity of the Sula River basin is that the dominant share of organic substances and nitrogen comes from diffuse sources. The relative contribution of distributed sources for BOD5, COD, and TN is 79%, 82%, and 55%, respectively. At the same time, for TP, the main pressure is formed by point sources. A similar pattern is characteristic of other river basins in Ukraine and around the world and is related to the peculiarities of the P geochemical cycle. The contribution of diffuse sources is due to the total natural background and the population without access to sewerage networks. Among the point sources, 82 - 89% of the pressure is associated with wastewater discharge from municipal enterprises. The results obtained should serve as a basis for developing measures to overcome the impact of anthropogenic pressure.
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Radu, Florina, Sofia Popescu, Antoanela Cozma, Alexandru Rinovetz y Bogdan Radoi. "EARLY REMEDIATION OF WASTEWATERS FROM ROMANIAN FOOD INDUSTRY: A CASE STUDY OF IMPROVING THE QUALITY OF DAIRY INDUSTRY WASTEWATER". En 22nd International Multidisciplinary Scientific GeoConference 2022. STEF92 Technology, 2022. http://dx.doi.org/10.5593/sgem2022v/3.2/s12.07.

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The purpose of this study was to demonstrate the role played by different wastewater treatment technologies in the dairy industry in the context of the challenges of sustainable development: water scarcity and conservation of water resources, the constant growth of the population and the costs of wastewater treatment in centralized systems, increasing constraints and stricter environmental protection regulations. In this sense, the efficiency of wastewater treatment plants belonging to a number of 8 factories was determined. The studied factories were divided into three groups according to the type of wastewater treatment technology, namely: the first group uses only the pretreatment stage; the second uses the mechanical-chemical and biological treatment stages with biogas production; the third group has an aerobic biological treatment coupled with a reverse osmosis module. Water samples were taken weekly from the influent and effluent of each wastewater treatment plant for 6 months (March-August 2022). A number of 8 quality parameters were analyzed for both waste water and treated water, in accordance with the national regulations. The results highlighted the fact that the values of chemical oxygen consumption (COD), five-days biochemical oxygen consumption (BOD5), total suspended solids (TSS), phosphorus (PTotal), respectively total nitrogen (NTotal), and ammonium nitrogen for all wastewater samples far exceeded the limits of admissibility provided by the national wastewater quality standards. Instead, the pH values and the chloride content were within acceptable limits. The apply of mechanical and biological wastewater treatments determined the decrease of COD, BOD5 and TSS concentrations by more than 95%, respectively by more than 85% in the case of PTotal. The efficiency of the reverse osmosis module was over 95% in the case of ammonium nitrogen elimination. As a result of the onsite implementation of these technologies for the treatment of wastewater from the dairy industry, the values of the quality indicators of the effluents were in accordance with the regulations regarding the discharge of treated water into natural receivers or into the urban sewage network without affecting the environment.
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Wibowo, Agus Hadi, Chairul Irawan, Abubakar Tuhuloula y Ridhayanti Mu'minah. "Treatment of Laboratory Wastewater with High Sulfate Concentrations Using <i>Eco-Enzyme </i>as an Environment-Friendly Coagulant". En 4th International Seminar on Fundamental and Application of Chemical Engineering. Switzerland: Trans Tech Publications Ltd, 2024. http://dx.doi.org/10.4028/p-f1xo4r.

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Laboratory activities for testing nitrogen levels of natural rubber production are carried out to determine the nitrogen content to meet the Standard Indonesian Rubber (SIR). The test parameters use hazardous chemicals such as strong acids, i.e. sulfuric acid, which have corrosive properties. Testing activities in the laboratory will produce by-products in the form of liquid wastewater containing high sulfate concentrations. A cheap and environmentally friendly wastewater treatment system is required in this research, namely a coagulation-flocculation system using eco-enzyme as a liquid coagulant. Eco-enzyme is a fermented product of household organic waste from the remaining vegetables and fruit peels that are still fresh with a 1:3:10 formula after around 3 months. The purpose of this research was to determine the levels of COD, TDS, and sulfate concentrations as an indicator of wastewater quality standards that are safe for the environment. It is necessary to know the effectiveness of the eco-enzyme as a coagulant in treating laboratory wastewater with various concentrations of 1, 5, 10, 20, and 40% v/v. As well as variations in monitoring time of 5, 10, 15, 20, and 30 days. In this study, laboratory waste treatment with Eco-Enzyme as a coagulant resulted in a decrease in sulfate levels at 29.8 mg/L found at 1% v/v Eco-Enzyme concentration with monitoring for 30 days. With levels of COD 263 mg/L, TDS 39.7 mg/L, and pH 7.01 at a concentration of 40% v/v Eco-Enzyme. The results of this study indicate that Eco-Enzyme can act as a natural coagulant that is environmentally friendly and can degrade laboratory liquid waste so that it meets wastewater quality standards that are safe for the environment.
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Informes sobre el tema "Refractory nitrogen and COD"

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A nitrogen-rich septage-effluent plume in a glacial aquifer, Cape Cod, Massachusetts, February 1990 through December 1992. US Geological Survey, 1996. http://dx.doi.org/10.3133/wsp2456.

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Map showing weight percent of total nitrogen in the surficial sediments of the Mid-Atlantic continental margin, Cape Cod to Albemarle Sound. US Geological Survey, 1990. http://dx.doi.org/10.3133/i1987c.

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