In this project, three separate experiments were conducted to assess heavy metal removal from metal aqueous solutions and synthetic landfill leachate by adsorption using low-cost natural adsorbents. Fundamental batch investigations indicated that the 4.0-4.75 mm crushed mollusk shells and the Sphagnum peat moss were the best adsorbents for cadmium and nickel removal, respectively. Peat moss was also found to have the highest adsorption capacities for manganese and cobalt adsorption. The adsorption capacities of the peat moss and crushed mollusk shells used as natural adsorbents for the adsorption of cadmium and nickel from binary aqueous solutions in fixed-bed columns under continuous flow conditions were investigated. The life expectancy of each adsorbent in the fixed-bed columns was also assessed for different hydraulic loading rates. The flow rate of 1.5 mL/min (surface loading of 27.52 cm3/cm2•day) and bed depth of 15 cm were identified as the better operational conditions from the column testing. The results indicated that 47.9% and 42.7% cadmium and nickel removal efficiencies could obtained under these operational conditions, respectively. Finally, the peat moss and the crushed mollusk shells were packed in bench-scale down-flow fixed-bed columns to evaluate their adsorption capacities as natural low-cost adsorbents for the removal of heavy metals from aerated and non-aerated synthetic landfill leachate. The flow rate applied in this operation was 1.5 mL/min (surface loading of 27.52 cm3/cm2•day). Peat was found to have the best adsorption capacities in columns treating aerated synthetic leachate for cadmium (78.6%) and nickel (83.8%) removal efficiencies. / Thesis (Master, Civil Engineering) -- Queen's University, 2008-01-31 22:37:34.381

In this research, the adsorptive capacities of kenaf, peat moss, hay, and peanut hulls were evaluated for the removal of TNT and 2,4-DCP from aqueous solutions. Adsorbent loading capacities determined by batch studies were verified by continuous column experiments. It was found that the adsorption capacity of the candidate adsorbents were significantly lower than granular activated carbon (GAC). The impact of surface modification techniques, such as surface oxidation, were evaluated to study the effect on adsorption capacity. At lower equilibrium concentrations of the adsorbate (less than 10 ppb), surface oxidation by ozone showed an increase in the adsorption capacity. The same trend was not observed with peroxone and ultrasound pretreatment. The adsorbent requirement for treating water contaminated with TNT and 2,4-DCP were calculated based on the adsorptive capacity of the adsorbents. Though the adsorbent requirements for the candidate adsorbents were considerably higher than granular activated carbon, the adsorbent requirement costs for most of the candidate adsorbents tested were competitive when compared to GAC costs.

Submitted by Erika Demachki (erikademachki@gmail.com) on 2015-11-12T17:47:20Z No. of bitstreams: 2 Dissertação - Lícia Aparecida da Silva - 2015.pdf: 2121079 bytes, checksum: b400adc1fa3f8a66302ba1e4bdd38eaf (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2015-11-12T17:50:37Z (GMT) No. of bitstreams: 2 Dissertação - Lícia Aparecida da Silva - 2015.pdf: 2121079 bytes, checksum: b400adc1fa3f8a66302ba1e4bdd38eaf (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-11-12T17:50:37Z (GMT). No. of bitstreams: 2 Dissertação - Lícia Aparecida da Silva - 2015.pdf: 2121079 bytes, checksum: b400adc1fa3f8a66302ba1e4bdd38eaf (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-08-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The present work describes the development of an analytical method for the removal of contaminant emerging Sodium Diclofenac (DCF) present in aqueous solutions. For the removal thereof, it is used as a natural adsorbent sawdust treated in acid medium. The detection and quantification of the analyte were Performed by High-Performance Liquid Chromatography (English, HPLC). The material was characterized according to the techniques of Infrared Spectroscopy and X-Ray Diffraction. The Point of Zero Charge (PZC) was obtained both for the sawdust treated in acid medium, and for the same in kind, obtaining values of 4.8 and 5.5, respectively. We chose to work with the adsorbent treated with acid in natural pH of the solution (6.43), since the adsorption was quite satisfactory (86%). It was determined the LD figures of merit (0.06 mg L-1) and LQ (0.2 mg L-1). The linearity was determined by construction of standard curves prepared in solvent and prepared curves with water samples fortified with the DCF standard. The obtained correlation coefficient was quite satisfactory (r = 0.9999) and the recovery values were between 86% and 117% to the study drug. It used Full Factorial Planning 23 for optimization of chemical variables that can have an effect on the adsorption process. The results obtained by the Pareto chart showed that the only variable that exerted influence on the adsorption was the mass of adsorbent. Therefore, it was determined by univariate optimization, as being 600 mg. To study the adsorption kinetics, it was determined the equilibration time of 180 min, and following the adsorption pseudosegunda-order model. The isotherm obtained was linearized and the result indicated that the adsorption follows the Langmuir model, ie, chemical adsorption occurs monolayer. / O presente trabalho descreve o desenvolvimento de uma metodologia analítica para a remoção do contaminante emergente Diclofenaco de Sódio (DCF) presente em soluções aquosas. Para a remoção do mesmo, utilizou-se como adsorvente natural a serragem de madeira tratada em meio ácido. A detecção e quantificação do analito foram realizadas por Cromatografia Líquida de Alta Eficiência (do inglês, HPLC). O adsorvente foi caracterizado segundo as técnicas de Espectroscopia de Infravermelho e Difração de Raios-X. O Ponto de Carga Zero (PCZ) foi obtido tanto para a serragem de madeira tratada em meio ácido, como para a mesma in natura, obtendo valores de 4,8 e 5,5, respectivamente. Optou-se por trabalhar com o adsorvente tratado com ácido em pH natural da solução (6,43), visto que a adsorção foi bastante satisfatória (86%). Determinou-se as figuras de mérito LD (0,06 mg L-1) e LQ (0,2 mg L-1). A linearidade foi determinada através da construção de curvas analíticas preparadas em solvente e curvas preparadas com amostras de água fortificadas com o padrão de DCF. O coeficiente de correlação obtido foi bastante satisfatório (r = 0,9999) e os valores de recuperação ficaram entre 86% e 117% para o fármaco em estudo. Utilizou-se Planejamento Fatorial Completo 23 para a otimização das variáveis químicas que podem exercer efeito sobre o processo de adsorção. Os resultados obtidos segundo o gráfico de Pareto demonstraram que a única variável que exerceu influência sobre a adsorção foi a massa do adsorvente. Sendo assim, a mesma foi determinada através de otimização univariada, como sendo de 600 mg. Para o estudo da cinética de adsorção, ficou definido o tempo de equilíbrio de 180 min, e a adsorção seguindo o modelo de pseudosegunda-ordem. A isoterma obtida foi linearizada e o resultado indicou que a adsorção segue o modelo de Langmuir, ou seja, ocorre adsorção química em monocamada.

Made available in DSpace on 2017-07-10T17:40:48Z (GMT). No. of bitstreams: 1 2014_Tese_Herbert_Nacke.pdf: 3662817 bytes, checksum: 26b0dca41181044d14f648fbf6ffe7e3 (MD5) Previous issue date: 2014-02-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work aimed to evaluate the performance of three biosorbents obtained from the bark of fruit (biosorbent C), the endosperm (biosorbent E) and from the endosperm plus seed coat (biosorbent E + T) of Jatropha (Jatropha curcas L.) in the removal of metals chromium (Cr3+), cadmium (Cd2+), copper (Cu2+) and zinc (Zn2+) in aqueous solutions. To elucidate the properties of biosorbents, the characterization by infrared spectroscopy (IR), scanning electron microscopy (SEM) and determination of the point of zero charge (pHPCZ) of the materials was performed. The study of the optimal conditions and mechanisms that control the adsorption of the aforementioned metals by the biosorbents was performed through the influence of the solution pH, the mass of biosorbent, the contact time between the solution and the biosorbent, the initial concentration of metals in solution (adsorption isotherms) and the temperature during adsorptive process (thermodynamics). The adsorption kinetics was evaluated using the mathematical models of pseudofirst and pseudosecond order, Elovich and intraparticle diffusion. The adsorption isotherms were linearized by mathematical models of Langmuir, Freundlich and Dubinin-Radushkevich. Was also performed the comparision of the biosorbents with activated charcoal, since this material is the mainly adsorbent used in the sorption process of metallic contaminants. In the characterization of biosorbents was observed that all three materials have a structure with proteins, lignin, cellulose, hemicellulose, lignocellulose, hydroxyl, carboxylic, carbonyl and phenol groups, which enable bonds with metallic ions in solution. Furthermore, it was observed that the surface morphology of the biosorbents has irregular appearance, indicating a porous surface and good adsorptive capacity. The biosorbents show a pHPCZ between 5 and 6. The optimal conditions for the adsorptive process were: pH of 5.5 for the metals Cr3+ and Cd2+ and 5.0 to Cu2+ and Zn2+, 8.0 g L-1 of biosorbent mass per volume of solution and a contact time between the biosorbents and the contaminated solutions of 60 min for all metals. The results obtained in the adsorption kinetics indicate that for all metals in the study, the biosorbents showed a better fit by pseudosegunda order model, indicating the occurrence of chemical adsorption. Considering the maximum adsorption capacities obtained by the mathematical model of Langmuir, the biosorbent C presents the following order of removal: Cd2+ > Cr3+ > Zn2+ > Cu2+ (29.66; 22.11; 14.85 and 11.54 mg g-1); whereas for the biosorbent E the order was: Cu2+ > Cd2+ > Cr3+ > Zn2+ (20.47; 19.56; 18.20 and 15.88 mg g-1) and for the biosorbent E+T it was obtained: Cd2+ > Cu2+ > Cr3+ > Zn2+ (34.67; 22.91; 22.88 and 16,67 mg g-1). Regarding the adsorption form, the results showed that for all metals the chemisorption controls the adsorptive process, with the occurrence of mono-and multilayers for Cr3+ and monolayers for Cd2+, Cu2+ and Zn2+. Based on the results obtained in this work, it is possible affirm that the three biosorbents derived from the biomass of Jatropha have potential for the remediation of water resources contaminated with the metals Cr3+, Cd2+, Cu2+ and Zn2+, also providing an alternative use of the waste generated in biodiesel production of this species, increasing the sustainability of their supply chain / Este trabalho objetivou avaliar o desempenho de três biossorventes obtidos a partir da casca dos frutos (biossorvente C), do endosperma (biossorvente E) e do endosperma mais tegumento das sementes (biossorvente E+T) de pinhão manso (Jatropha curcas L.) na remoção dos metais cromo (Cr3+), cádmio (Cd2+), cobre (Cu2+) e zinco (Zn2+) de soluções aquosas. Para elucidação das propriedades dos biossorventes foi realizada a caracterização por espectroscopia de infravermelho (IV), microscopia eletrônica de varredura (MEV) e determinação do ponto de carga zero (pHPCZ) dos materiais. O estudo das condições ideais e dos mecanismos que controlam a adsorção dos metais supracitados pelos biossorventes foi realizado por meio da influência do pH da solução, da massa dos biossorventes, do tempo de contato entre a solução e os biossorventes, da concentração inicial dos metais na solução (isotermas de adsorção) e da temperatura durante o processo adsortivo (termodinâmica). A cinética de adsorção foi avaliada por meio dos modelos matemáticos de pseudoprimeira e pseudosegunda ordem, de Elovich e de difusão intrapartícula. As isotermas de adsorção foram linearizadas pelos modelos matemáticos de Langmuir, Freundlich e Dubinin-Radushkevich. Realizou-se ainda a comparação dos biossorventes com carvão ativado, uma vez que este material é o principal adsorvente utilizado em processos de sorção de contaminantes metálicos. Na caracterização dos biossorventes observou-se que os três materiais apresentam em sua estrutura proteínas, lignina, celulose, hemicelulose, lignocelulose, grupos hidroxílicos, carboxílicos, carbonílicos e fenóis, os quais possibilitam ligações com íons metálicos em solução. Além disto, observou-se que morfologia superficial dos biossorventes tem aspecto irregular, indicando uma superfície porosa e com boa capacidade adsortiva. Os biossorventes apresentaram ainda um pHPCZ entre 5 e 6. As condições ideais do processo adsortivo foram: pH da solução de 5,5 para os metais Cr3+ e Cd2+ e 5,0 para o Cu2+ e o Zn2+, 8,0 g L-1 de massa de biossorvente por volume de solução e um tempo de contato entre os biossorventes e as soluções contaminadas de 60 min para todos os metais. Os resultados obtidos na cinética de adsorção indicam que para todos os metais em estudo, os biossorventes apresentaram melhor ajuste pelo modelo de pseudosegunda ordem, indicando a ocorrência de adsorção química. Considerando as capacidades máximas de adsorção obtidas pelo modelo matemático de Langmuir, o biossorvente C apresenta a seguinte ordem de remoção: Cd2+ > Cr3+ > Zn2+ > Cu2+ (29,66; 22,11; 14,85 e 11,54 mg g-1); ao passo que para o biossorvente E a ordem foi: Cu2+ > Cd2+ > Cr3+ > Zn2+ (20,47; 19,56; 18,20 e 15,88 mg g-1) e para o biossorvente E+T obteve-se: Cd2+ > Cu2+ > Cr3+ > Zn2+ (34,67; 22,91; 22,88 e 16,67 mg g-1). A aplicação do modelo de Dubinin-Radushkevich demonstrou que a adsorção de todos os metais pelos biossorventes se dá por quimiossorção, com a ocorrência de mono e multicamadas para o Cr3+ e monocamadas para o Cd2+, o Cu2+ e o Zn2+. Baseado nos resultados obtidos neste trabalho, é possível afirmar que os três biossorventes oriundos da biomassa de pinhão manso apresentam potencial para a remediação de recursos hídricos contaminados com os metais Cr3+, Cd2+, Cu2+ e Zn2+, proporcionando ainda, uma alternativa de uso dos resíduos gerados na produção de biodiesel desta espécie, aumentando a sustentabilidade da sua cadeia produtiva

In this research, the adsorptive capacities of kenaf in the forms of chopped whole stalk, chopped core, and bast materials were evaluated for the removal of lead, zinc, and toluene from contaminated synthetic waste streams using traditional adsorption isotherm techniques. The effect of surface oxidation using ozone was observed with respect to the adsorption of metals. Hydraulic conductivity experiments were conducted to evaluate the head loss associated with packing a column with kenaf fibers and to determine the suitability of its use in dynamic packed column systems. B.E.T. surface areas were determined as well. Under increasingly stringent regulatory requirements, even low level organic and inorganic contamination (under 100 ppm) in surface and ground waters must be treated. This study is part of an ongoing multi-year research effort aiming to develop a kenaf-based biosorptive process to improve treatment of contaminated aqueous streams at reduced costs and technical complexity.