Nutrients (nitrogen and phosphorus) should be removed and recycled from wastewater in order to reduce the nutrient load to recipient waters, avoiding contamination of groundwater and conserve resources. There is a need to pay more attention to phosphorus (P) removal and recycling from wastewater due to limited availability of phosphorus recourses. For such purpose reactive filter media can be used to remove nutrient from wastewater as a sustainable technology. The present study was aimed to evaluate calcium silicate hydrate crystallization in Absol as a reactive filter media for removal and recycle of phosphorus from household wastewater and assess physical and chemical characteristics of Absol. A study of the color removing capacity of Absol was also performed. Several batch experiments were done for comparing absorption mechanism. Collected data were applied to Langmuir and Freundlich isotherm models to study type of adsorption isotherms and pseudofirst- order and second order models were run for study of adsorption kinetics. The experiment demonstrated a very high P and Methylene Blue (MB) sorption capacity. The amount of adsorbed P and MB vary with initial solution concentrations, contact time, and adsorbent dosage. Both equilibrium data (P, MB) were fitted very well in the Langmuir isotherm equation, confirming the monolayer physical sorption and adsorption kinetic followed by the pseudo-second order kinetic model. It is concluded that Absol can have potential to be use for the removal of P, textile dye contaminants and probably also pharmaceuticals present in wastewater.

A adsorção de metais em solos tem sido estudada no escopo da geotecnia ambiental principalmente para prever formação de plumas, estudar viabilidade de técnicas de remediação e projetar revestimentos impermeabilizantes em sistemas de disposição de resíduos, entre outros. A consideração da adsorção como um fenômeno imediato e reversível é geralmente aceitável nessas aplicações, porém tem-se verificado que para solos tropicais o estudo da cinética pode melhorar as retroanálises de dados de campo e as interpretações de resultados experimentais. Este trabalho apresenta aspectos teóricos da cinética de adsorção, incluindo fatores que afetam a cinética de adsorção, modelos para determinar os mecanismos que controlam a cinética de adsorção e modelos de cinética de adsorção. A adsorção e a cinética de adsorção de cádmio e chumbo em um Latossolo roxo foram investigadas por meio de ensaios de adsorção tipo Batch. As concentrações iniciais nas soluções variaram de 2 mg/L até 2000 mg/L. OS tempos de contatos variaram de 5 minutos até 6 meses. Também foram realizados ensaios de extração e digestão química. A seguir, foram aplicados modelos para determinar os mecanismos que controlam a cinética de adsorção e também foram ajustados modelos de cinética de adsorção aos dados experimentais. Os resultados mostram que a adsorção pode ser representada por dois distintos comportamentos: curto prazo, até cerca de 8 horas, e longo prazo, para tempos superiores. A adsorção não específica aumenta com o aumento da concentração do contaminante na fase sólida no caso do cádmio, enquanto para o chumbo esta relação não ficou clara. Os modelos de cinética de adsorção testados representam apenas o comportamento de curto prazo e o ajuste desses modelos aos dados experimentais, mesmo para a adsorção de curto prazo, varia consideravelmente em função do método matemático utilizado. Finalmente, concluiu-se que a cinética de adsorção é bem representada por uma função tipo potência com expoente negativo. / Metal adsorption in soils has been studied in the scope of environmental geotechnics mainly to predict migration of contaminant plumes, to study feasibility of remediation techniques, and to design waste disposal sites. The consideration of adsorption as an immediate and reversible phenomenon is generally accepted in those applications; however, the study of adsorption kinetics in tropical soils may improve back-calculation of field data and interpretation of experimental results. This study presents theoretical aspects of adsorption kinetics, including factors that affect adsorption kinetics, models to determine mechanisms that control adsorption kinetics and adsorption kinetics models. Adsorption and adsorption kinetics of cadmium and lead in a Brazilian lateritic red clay were investigated by means of Batch adsorption tests on. Initial solutions concentrations varied from 2 mg/L to 2000 mg/L. Contact times varied from 5 minutes to 6 months. Chemical extraction and digestion tests were also performed. Models were then applied to experimental data to determine the mechanisms that control adsorption kinetics and adsorption kinetics models were also fitted to experimental data. The results show that adsorption can be represented by two different behaviors: a short time behavior, until circa 8 hours, and a long time behavior, for longer times. For cadmium, the importance of non specific adsorption increases as the contaminant concentration in the solid phase increases, while this relation is not clear for lead. The investigated adsorption kinetics models can only represent the short time behavior, and fitting of these models, even for short-time adsorption, depends considerably on the utilized mathematical method. Finally, adsorption kinetics can be well represented by a power function with negative exponent.

A adsorção de metais em solos tem sido estudada no escopo da geotecnia ambiental principalmente para prever formação de plumas, estudar viabilidade de técnicas de remediação e projetar revestimentos impermeabilizantes em sistemas de disposição de resíduos, entre outros. A consideração da adsorção como um fenômeno imediato e reversível é geralmente aceitável nessas aplicações, porém tem-se verificado que para solos tropicais o estudo da cinética pode melhorar as retroanálises de dados de campo e as interpretações de resultados experimentais. Este trabalho apresenta aspectos teóricos da cinética de adsorção, incluindo fatores que afetam a cinética de adsorção, modelos para determinar os mecanismos que controlam a cinética de adsorção e modelos de cinética de adsorção. A adsorção e a cinética de adsorção de cádmio e chumbo em um Latossolo roxo foram investigadas por meio de ensaios de adsorção tipo Batch. As concentrações iniciais nas soluções variaram de 2 mg/L até 2000 mg/L. OS tempos de contatos variaram de 5 minutos até 6 meses. Também foram realizados ensaios de extração e digestão química. A seguir, foram aplicados modelos para determinar os mecanismos que controlam a cinética de adsorção e também foram ajustados modelos de cinética de adsorção aos dados experimentais. Os resultados mostram que a adsorção pode ser representada por dois distintos comportamentos: curto prazo, até cerca de 8 horas, e longo prazo, para tempos superiores. A adsorção não específica aumenta com o aumento da concentração do contaminante na fase sólida no caso do cádmio, enquanto para o chumbo esta relação não ficou clara. Os modelos de cinética de adsorção testados representam apenas o comportamento de curto prazo e o ajuste desses modelos aos dados experimentais, mesmo para a adsorção de curto prazo, varia consideravelmente em função do método matemático utilizado. Finalmente, concluiu-se que a cinética de adsorção é bem representada por uma função tipo potência com expoente negativo. / Metal adsorption in soils has been studied in the scope of environmental geotechnics mainly to predict migration of contaminant plumes, to study feasibility of remediation techniques, and to design waste disposal sites. The consideration of adsorption as an immediate and reversible phenomenon is generally accepted in those applications; however, the study of adsorption kinetics in tropical soils may improve back-calculation of field data and interpretation of experimental results. This study presents theoretical aspects of adsorption kinetics, including factors that affect adsorption kinetics, models to determine mechanisms that control adsorption kinetics and adsorption kinetics models. Adsorption and adsorption kinetics of cadmium and lead in a Brazilian lateritic red clay were investigated by means of Batch adsorption tests on. Initial solutions concentrations varied from 2 mg/L to 2000 mg/L. Contact times varied from 5 minutes to 6 months. Chemical extraction and digestion tests were also performed. Models were then applied to experimental data to determine the mechanisms that control adsorption kinetics and adsorption kinetics models were also fitted to experimental data. The results show that adsorption can be represented by two different behaviors: a short time behavior, until circa 8 hours, and a long time behavior, for longer times. For cadmium, the importance of non specific adsorption increases as the contaminant concentration in the solid phase increases, while this relation is not clear for lead. The investigated adsorption kinetics models can only represent the short time behavior, and fitting of these models, even for short-time adsorption, depends considerably on the utilized mathematical method. Finally, adsorption kinetics can be well represented by a power function with negative exponent.

Adsorption/desorption behaviors of three volatile organic compounds (VOCs) emitted from the optoelectronics industry by Y-type and ZSM-5 zeolites were studied in this work. Target VOCs include acetone, isopropyl alcohol (IPA), and propylene glycol monomethyl ether acetate (PGMEA). Adsorption/desorption experiments were conducted in a fixed-bed column using various operating conditions to mimic the commercial ones. Also studied include the adsorption kinetics for single-component, two-component, and three-component cases. Experimental results of the single-adsorbate case by both model zeolites have shown that the amount of VOC adsorbed follows the order of PGMEA > IPA > Acetone. This is ascribed to the greatest molecular weight of PGMEA among three VOCs tested. The adsorption capacity of each zeolite for each target VOC was found to increase with its increasing initial concentration. Freundlich isotherm and Langmuir isotherm were found to be suitable for describing the adsorption behaviors for the single-adsorbate case. Results of the desorption experiments also showed that most of the target VOCs could be desorbed at 180¢J in 100 minutes. The adsorption capacities of the regenerated model zeolites were found to be decreasing as the regeneration times increased. As compared with the fresh ones, the regenerated zeolites had reduced specific surface areas, but increased pore sizes. In addition, the Yoon and Nelson equation was employed to study the kinetic behaviors of adsorbing the target VOCs by the model zeolites. A good agreement of the experimental results and predictions by the Yoon & Nelson model was obtained for the single-adsorbate case. However, the Yoon and Nelson model was found to be incompetent to simulate and predict all the multi-adsorbate cases including two-component adsorption and three-component adsorption in this work. Again, it is speculated that the displacement of lower-molecular-weight adsorbates (i.e., acetone and IPA) by PGMEA (an adsorbate of a much greater molecular weight) would be responsible for this finding. For the two-adsorbate case, nevertheless, the Yoon and Nelson equation was found to be capable of describing the adsorption behavior under the circumstance of C/C0 < 1.

Submitted by Marilene Donadel (marilene.donadel@unioeste.br) on 2018-10-26T00:04:37Z No. of bitstreams: 1 Francimeiri_Borsato_2018.pdf: 2616199 bytes, checksum: 0597ddbb345dfc4d204c2b2092f5ee59 (MD5) / Made available in DSpace on 2018-10-26T00:04:37Z (GMT). No. of bitstreams: 1 Francimeiri_Borsato_2018.pdf: 2616199 bytes, checksum: 0597ddbb345dfc4d204c2b2092f5ee59 (MD5) Previous issue date: 2018-07-25 / This work has evaluated the adsorption capability of three coal produced in the Universidade Estadual do Oeste do Paraná (tilapia bone residual coal, soybean bark coal and chestnut from Pará) and other kind of coal commercially obtained (babaçu coconut pealing coal) to remove the metronidazole from aqueous solution. The coal which better absorbed the metranidazole was the babaçu coconut peal one (CCCB) with temperature from 40ºC, 150 rpm of stirring and with no pH adjustment. Thus, the kinetic tests were performed by using the SOTAX dissolution apparatus, with 1000 mL of metronidazole solution, varying the concentration (200, 400, 650 and 850 mg/ L) and the temperature (30, 40, 45ºC), 1 g of the coal and 150 rpm of stirring. The equilibrium time observed was around 20 hours and in the first 4 hours a bigger amount of metranidazole was adsorbed, this inicial amount corresponds to the metranidazole adsorption in the outer layer of the CCCB. The results obtained from the adsorption kinetics were described by the intraparticule diffusion in which were verified the appearing of four well defined regions corresponding to the adsorption in the outer layer, in the macropores, in the CCCB mesopores and the equilibrium, respectively. In the equilibrium studies, were presented two adsorption mechanisms: monolayer and multilayer with increasing concentration of the adsorbate, corresponding to the hybrid model of Langmuir + BET. The removing process of metranidazole by using CCCB became economically viable due to the low cost in the obtention or production of the adsorbent, the easily extracetion of the babaçu coconut biomass and the excellent capability of maximum adsorptive to the metranidazole. / Neste trabalho, avaliou-se a capacidade de adsorção de três carvões produzidos na Universidade Estadual do Oeste do Paraná (carvão do resíduo ósseo de tilápia, carvão da casca da soja e o carvão da casca da castanha do Pará) e um carvão obtido comercialmente (carvão da casca do coco babaçu) para remoção do antibiótico metronidazol de solução aquosa. O carvão que melhor adsorveu o metronidazol foi o carvão da casca do coco babaçu (CCCB) com temperatura de 40ºC, 150 rpm de agitação e sem ajuste de pH. Dessa forma, os testes cinéticos foram realizados com o auxílio de um dissolutor (Sotax), utilizando 1000 mL de solução de metronidazol, variando a concentração (200, 400, 650 e 850 mg L-1) e a temperatura (30, 40 e 45ºC), 1 g do carvão e 150 rpm de agitação. O tempo de equilíbrio observado foi de aproximadamente 20 horas e nas primeiras 4 horas uma maior quantidade de metronidazol foi adsorvida, essa quantidade inicial corresponde à adsorção do metronidazol na camada externa do CCCB. Os dados obtidos a partir da cinética de adsorção foram descritos pelo modelo de difusão intrapartícula, no qual verificou-se o aparecimento de quatro regiões bem definidas correspondendo respectivamente a adsorção na camada externa, nos macroporos, nos mesoporos do CCCB e por último o equilíbrio. No estudo de equilíbrio, apresentou dois mecanismos de adsorção: monocamada e multicamadas com o aumento da concentração do adsorvato, correspondendo ao modelo híbrido de Langmuir+ BET. O processo de remoção de metronidazol utilizando o CCCB é economicamente viável visto o baixo custo na obtenção ou fabricação do adsorvente por ser extraído da biomassa do coco babaçu, além de possuir uma excelente capacidade máxima adsortiva para o antibiótico estudado.

The aim of this study was to determine the adsorption capacity of activated carbon and organo-zeolites for removal of pesticides in water. In order to prepare organo-zeolite, two kinds of cationic surfactants, namely, hexadecyltrimethyl ammonium bromide (HTAB) and dodecyltrimethyl ammonium bromide (DTAB) were used. Adsorption studies of cationic surfactant on zeolite were investigated in respect to initial concentration of cationic surfactant, time, and temperature. It has been found that the best fitted isotherm equation was Langmuir equation. The observed adsorption rates were found to be equal to the second order kinetic model. The activation energies of cationic surfactant adsorption was determined by using Arrhenius equation.

Dans ce travail, l'adsorption de protéines globulaires sur des surfaces modifiées a été investiguée par ellipsométrie et par réflectivité de neutrons.<p><p>L'adsorption de myoglobine deutérée sur des monocouches hydrophobes d'OTS et de PS a été étudiée par réflectivité de neutrons pour des solutions de protéines de différentes concentrations (de 1 mg/ml à 0.01 mg/ml). A basse concentration, les protéines adsorbées se dénaturent et s'étalent sur le substrat hydrophobe et l'adsorption résulte en une fine couche dense en protéines. Sur le PS, les protéines s'étalent moins, ce qui est en accord avec la moindre hydrophobicité du PS. A haute concentration, une couche supplémentaire peu dénaturée est observée au-dessus de la première couche.<p><p>La cinétique d'adsorption primaire de HSA a été étudiée par ellipsométrie sur des brosses de PEG (Mw = 35700 Da) de différentes densités de greffage. Les résultats confirment que les brosses de PEG répriment l'adsorption de protéines. En outre, l'adsorption est très rapide sur le PS, tandis que sur les brosses, l'adsorption est plus lente. Le comportement à temps long de la quantité adsorbée Γ en fonction de la densité de greffage σ est en accord semi-quantitatif avec une théorie développée par Halperin et basée sur les différentes contributions à l'énergie libre d'une protéine adsorbée. Il a également été mis en évidence un régime pour lequel le taux d'adsorption dΓ/dt décroît exponentiellement avec la quantité de protéines adsorbées Γ.<p><p>L'adsorption de protéines (lysozyme, HSA et myoglobine) a ensuite été étudiée sur des brosses de PNIPAM en fonction des paramètres de la brosse et de la température. Les brosses ont été greffées par ATRP à partir d'une monocouche d'OEG (oligo éthylène glycol) silanisé contenant du brome comme initiateur. Il a été montré que l'adsorption primaire sur la surface de greffage est inférieure à 0.1 mg/m^2 et que l'adsorption ternaire dans la brosse, en dessous et au-dessus de la LCST, ne dépasse pas 1 mg/m^2 (~ 2% de fraction volumique en protéines). La résistance à l'adsorption a été associée à la présence d'une région hydrophile superficielle qui pourrait présenter une barrière cinétique à l'adsorption des protéines dans le cœur moins polaire de la brosse.<p><p>L'ensemble de ces résultats montre que les propriétés interfaciales du substrat jouent un rôle crucial dans les processus d'adsorption des protéines. <p> / Doctorat en Sciences / info:eu-repo/semantics/nonPublished