Application of succinylated sugarcane bagasse as adsorbent to remove methylene blue and gentian violet from aqueous solutions - Kinetic and equilibrium studies

In a previous work, succinylated sugarcane bagasse (SCB 2) was prepared from sugarcane bagasse (B) using succinic anhydride as modifying agent. In this work the adsorption of cationic dyes onto SCB 2 from aqueous solutions was investigated. Methylene blue, MB, and gentian violet, GV, were selected as adsorbates. The capacity of SCB 2 to adsorb MB and GV from aqueous single dye solutions was evaluated at different contact times, pH, and initial adsorbent concentration. According to the obtained results, the adsorption processes could be described by the pseudo-second-order kinetic model. Adsorption isotherms were well fitted by Langmuir model. Maximum adsorption capacities for MB and GV onto SCB 2 were found to be 478.5 and 1273.2 mg/g, respectively. (C) 2011 Elsevier Ltd. All rights reserved.Universidade Federal de Ouro PretoFAPEMIGCNPqCAPE

Mercerização e modificação química de celulose e bagaço de cana-de-açúcar com anidrido succínico e trietilenotetramina : preparação de novos materiais quelantes para a adsorção de Pb (II), Cd (II), Cr (VI) e Cu (II).

A celulose e o bagaço de cana-de-açúcar foram usados na preparação de novos materiais quelantes para a adsorção de metais pesados. Foram realizadas modificações físicas e químicas nesses biopolímeros com o objetivo de preparar materiais para adsorver metais pesados como o chumbo, o cádmio, o cobre e o cromo. Essas modificações incluem a mercerização da celulose e do bagaço de cana-de-açúcar e o tratamento dos materiais não mercerizados e mercerizados com anidrido succínico para a introdução de funções ácido carboxílico. Em seguida essas funções ácidas foram modificadas com trietilenotetramina, um ligante polidentado, para o ancoramento de grupos amina nos materiais. Esses grupos amina foram quaternizados usando iodeto de metila para a obtenção de grupos amônio quaternários. Os efeitos da mercerização foram avaliados pelas técnicas de difração de raios-X, FTIR e TGA-DTA. Os materiais obtidos pelas modificações químicas foram caracterizados por FTIR, TGA-DTA e análise elementar de C, H e N. Os ganhos de massa e as concentrações de funções ácidas e básicas introduzidas foram calculados. A celulose e o bagaço de cana mercerizados succinilados apresentaram em relação à celulose e o bagaço de cana não mercerizados succinilados um aumento de 7,1 e 12,1% no ganho de massa e de 0,4 e 0,2 mmol/g na concentração de funções ácido carboxílico respectivamente. A celulose e o bagaço de cana mercerizados succinilados modificados com trietilenotetramina apresentaram em relação à celulose e o bagaço de cana não mercerizados succinilados modificados com trietilenotetramina um aumento de 13,7 e 5,1% no ganho de massa e de 0,8 e 0,3 mmol/g na concentração de funções amina respectivamente. Um dos materiais contendo grupos amina foi quaternizado visando a preparação de um material contendo grupos amônio quaternários capazes de realizar troca-aniônica. Os materiais quelantes obtidos foram usados em estudos de adsorção e suas capacidades máximas de adsorção foram avaliadas pelo modelo de Langmuir e comparadas. A celulose e o bagaço de cana mercerizados succinilados apresentaram em relação à celulose e o bagaço de cana não mercerizados succinilados um aumento na capacidade de adsorção de 32,6 e 83,3 mg/g de Pb2+, 16,3 e 43,6 mg/g de Cd2+, 17,5 e zero mg/g de Cu2+ respectivamente, o que comprova a eficiência da mercerização na preparação de materiais com maior poder de adsorção.Cellulose and sugarcane bagasse were used in the preparation of new chelating materials for adsorption of heavy metals. Physical and chemical modifications were accomplished in those biopolymers aiming the preparation of materials able to adsorb heavy metals as lead, cadmium, copper and chromium. Those modifications include the non-mercerization of cellulose and sugarcane bagasse and the treatment of mercerized and mercerized materials with succinic anhydride for the introduction of carboxylic acid functions. Then, those acid functions were modified with triethylenetetramine, as a polydentate ligand, to anchor amine groups to the materials. Those amine groups were quaternized using methyl-iodide to obtain quaternary ammonium groups. Mercerization effects were evaluated by x-ray diffraction, FTIR and TGA-DTA. The materials obtained by chemical modifications were characterized by FTIR, TGA-DTA and elemental analysis of C, H and N. Mass gains and the concentrations of introduced acid and basic functions were calculated. Compared to succinylated non-mercerized cellulose and sugarcane bagasse, succinylated mercerized cellulose and sugarcane bagasse showed an increase of 7.1 and 12.1% in the mass gain and 0.4 and 0.2 mmol/g in the concentration of carboxylic acid functions respectively. Compared to succinylated non-mercerized cellulose and sugarcane bagasse modified with triethylenetetramine, succinylated mercerized cellulose and sugarcane bagasse modified with triethylenetetramine showed an increase of 13.7 and 5.1% in the mass gain and 0.8 and 0.3 mmol/g in the concentration of amine functions respectively. One of the materials containing amine groups was quaternized in order to prepare a material containing quaternary ammonium groups capable of accomplishing anionic exchange. The chelating materials obtained were used in studies of adsorption and their maximum adsorption capacities were evaluated by Langmuir model and compared. Compared to succinylated non-mercerized cellulose and sugarcane bagasse, succinylated mercerized cellulose and sugarcane bagasse showed an increase in adsorption capacity of 32.6 and 83.3 mg/g of Pb2+, 16.3 and 43.6 mg/g of Cd2+, 17.5 and zero mg/g of Cu2+, respectively. Thus, it is proven the efficiency of mercerization in the preparation of materials with greater power of adsorption

Mercerização e modificação química de celulose e bagaço de cana-de-açúcar com anidrido succínico e trietilenotetramina : preparação de novos materiais quelantes para a adsorção de Pb (II), Cd (II), Cr (VI) e Cu (II).

A celulose e o bagaço de cana-de-açúcar foram usados na preparação de novos materiais quelantes para a adsorção de metais pesados. Foram realizadas modificações físicas e químicas nesses biopolímeros com o objetivo de preparar materiais para adsorver metais pesados como o chumbo, o cádmio, o cobre e o cromo. Essas modificações incluem a mercerização da celulose e do bagaço de cana-de-açúcar e o tratamento dos materiais não mercerizados e mercerizados com anidrido succínico para a introdução de funções ácido carboxílico. Em seguida essas funções ácidas foram modificadas com trietilenotetramina, um ligante polidentado, para o ancoramento de grupos amina nos materiais. Esses grupos amina foram quaternizados usando iodeto de metila para a obtenção de grupos amônio quaternários. Os efeitos da mercerização foram avaliados pelas técnicas de difração de raios-X, FTIR e TGA-DTA. Os materiais obtidos pelas modificações químicas foram caracterizados por FTIR, TGA-DTA e análise elementar de C, H e N. Os ganhos de massa e as concentrações de funções ácidas e básicas introduzidas foram calculados. A celulose e o bagaço de cana mercerizados succinilados apresentaram em relação à celulose e o bagaço de cana não mercerizados succinilados um aumento de 7,1 e 12,1% no ganho de massa e de 0,4 e 0,2 mmol/g na concentração de funções ácido carboxílico respectivamente. A celulose e o bagaço de cana mercerizados succinilados modificados com trietilenotetramina apresentaram em relação à celulose e o bagaço de cana não mercerizados succinilados modificados com trietilenotetramina um aumento de 13,7 e 5,1% no ganho de massa e de 0,8 e 0,3 mmol/g na concentração de funções amina respectivamente. Um dos materiais contendo grupos amina foi quaternizado visando a preparação de um material contendo grupos amônio quaternários capazes de realizar troca-aniônica. Os materiais quelantes obtidos foram usados em estudos de adsorção e suas capacidades máximas de adsorção foram avaliadas pelo modelo de Langmuir e comparadas. A celulose e o bagaço de cana mercerizados succinilados apresentaram em relação à celulose e o bagaço de cana não mercerizados succinilados um aumento na capacidade de adsorção de 32,6 e 83,3 mg/g de Pb2+, 16,3 e 43,6 mg/g de Cd2+, 17,5 e zero mg/g de Cu2+ respectivamente, o que comprova a eficiência da mercerização na preparação de materiais com maior poder de adsorção.Cellulose and sugarcane bagasse were used in the preparation of new chelating materials for adsorption of heavy metals. Physical and chemical modifications were accomplished in those biopolymers aiming the preparation of materials able to adsorb heavy metals as lead, cadmium, copper and chromium. Those modifications include the non-mercerization of cellulose and sugarcane bagasse and the treatment of mercerized and mercerized materials with succinic anhydride for the introduction of carboxylic acid functions. Then, those acid functions were modified with triethylenetetramine, as a polydentate ligand, to anchor amine groups to the materials. Those amine groups were quaternized using methyl-iodide to obtain quaternary ammonium groups. Mercerization effects were evaluated by x-ray diffraction, FTIR and TGA-DTA. The materials obtained by chemical modifications were characterized by FTIR, TGA-DTA and elemental analysis of C, H and N. Mass gains and the concentrations of introduced acid and basic functions were calculated. Compared to succinylated non-mercerized cellulose and sugarcane bagasse, succinylated mercerized cellulose and sugarcane bagasse showed an increase of 7.1 and 12.1% in the mass gain and 0.4 and 0.2 mmol/g in the concentration of carboxylic acid functions respectively. Compared to succinylated non-mercerized cellulose and sugarcane bagasse modified with triethylenetetramine, succinylated mercerized cellulose and sugarcane bagasse modified with triethylenetetramine showed an increase of 13.7 and 5.1% in the mass gain and 0.8 and 0.3 mmol/g in the concentration of amine functions respectively. One of the materials containing amine groups was quaternized in order to prepare a material containing quaternary ammonium groups capable of accomplishing anionic exchange. The chelating materials obtained were used in studies of adsorption and their maximum adsorption capacities were evaluated by Langmuir model and compared. Compared to succinylated non-mercerized cellulose and sugarcane bagasse, succinylated mercerized cellulose and sugarcane bagasse showed an increase in adsorption capacity of 32.6 and 83.3 mg/g of Pb2+, 16.3 and 43.6 mg/g of Cd2+, 17.5 and zero mg/g of Cu2+, respectively. Thus, it is proven the efficiency of mercerization in the preparation of materials with greater power of adsorption

Acid hydrolysis of sugarcane bagasse: kinetic study of cellulose saccharification for ethanol production

O bagaço de cana-de-açúcar é um resíduo gerado no processo de produção de açúcar e álcool pelas usinas. O histórico de uso desse material aponta para a queima visando à produção de vapor e energia para o processo. As necessidades ambientais e econômicas ligadas tanto à emissão de gases estufa quanto as áreas agricultáveis apontam para um melhor aproveitamento desse resíduo que é constituído de cerca de 50% de celulose, 28% de hemiceluloses (também chamadas polioses), 21% de lignina e 1% de inorgânicos. Dentro desse contexto este trabalho visou à utilização da celulose do bagaço para a obtenção de açúcares fermentescíveis para a produção de etanol de 2ª geração. O bagaço foi desmedulado e a fração fibra foi pré-hidrólisada visando eliminar as hemiceluloses. Em seguida a fração fibra pré-hidrolisada foi deslignificada através de polpação soda antraquinona (SAQ). A polpa celulósica da fração fibra do bagaço foi hidrolisada em ácido sulfúrico e ácido clorídrico através do método \"ELA\", extremely low acid. Esse método utiliza ácido mineral muito diluído, altas temperaturas e pressões. As temperaturas de hidrólise utilizadas compreenderam a faixa de 180 a 230°C e as concentrações de ácido sulfúrico e ácido clorídrico utilizadas foram 0,07%, 0,14% e 0,28% e 0,05%, 0,10% e 0,20%, respectivamente. A razão sólido-líquido empregada foi 1:20 (m/v) e os reatores utilizados foram de aço inox 316L. A perda de massa após os experimentos de hidrólise foi quantificada e a composição dos hidrolisados foi analisada por cromatografia líquida de alta eficiência (CLAE). Paralelamente um estudo de degradação de glicose em ácido sulfúrico e ácido clorídrico foi conduzido com o objetivo de minimizar a degradação de glicose e conseqüentemente aumentar o seu rendimento. Através desse estudo também foi possível comparar o efeito de cada ácido na cinética de degradação de glicose. A faixa de temperatura utilizada foi de 200 a 220°C e a faixa de concentração de ácido sulfúrico e ácido clorídrico foi a mesma empregada nos estudos de hidrólise ácida. As constantes de velocidade de ordem um obtidas através de regressões lineares dos dados de perda de massa foram utilizadas para calcular a energia de ativação de Arrhenius. As energias de ativação médias obtidas para a reação com H2SO4 e HCl foram 184.9 e 183.5 kJ/mol, respectivamente. O rendimento máximo de glicose para a hidrólise da polpa celulósica em H2SO4 foi 69,8% e em HCl foi 70,2%. As constantes de velocidade de ordem um obtidas através de regressões lineares dos dados de glicose residual para a degradação de glicose também foram utilizadas para calcular a energia de ativação de Arrhenius. As energias de ativação médias para a decomposição de glicose em H2SO4 e HCl foram 124.5 e 142.9 kJ/mol, respectivamente. Através dos estudos realizados foi possível concluir que HCl foi um catalisador mais efetivo que o H2SO4 com base no valor das constantes de velocidade determinadas e nos rendimentos máximos de glicose obtidos. Porém, o HCl é menos vantajoso economicamente que o H2SO4 e os íons cloreto são responsáveis por tornar esse ácido mais corrosivo que o H2SO4.Sugarcane bagasse is a residue from sugar and alcohol production process. In the industry of sugar and alcohol this residue is burned to produce steam and energy for the process. The environmental and economic needs related to both emission of greenhouse gases and the increase of sugarcane planted area point to be a better utilization of the bagasse. The approximate composition of sugarcane bagasse is 50% cellulose, 28% hemicelluloses, 21% lignin and 1% inorganic compounds. From this view point, this work aimed to use cellulose from sugarcane bagasse to obtain fermentable sugars to produce second generation ethanol. Depithed bagasse was pre-hydrolyzed to remove hemicelluloses. Afterwards, pre-hydrolyzed depithed bagasse was pulped using soda-anthraquinone (SAQ) method to remove lignin. Cellulosic pulp was hydrolyzed employing the ELA conditions. Sulphuric acid and hydrochloric acid were chosen as hydrolysis catalysts. The ELA uses mineral acid in extremely low concentration, high temperatures and pressures. The temperature range chosen for kinetic study was from 180 to 230°C. The H2SO4 concentration was 0.07%, 0.14%, and 0.28% and HCl concentration was 0.05%, 0.10%, and 0.20%. In hydrolysis experiments the solid-liquid ratio employed was 1:20. Reactors resistant to acid corrosion made by 316L-stainless steel were used in the experiments. The weight loss after the hydrolysis experiments was determined and the hydrolysate composition was analyzed by high performance liquid chromatography (HPLC). A study of glucose decomposition in both acid catalysts was also carried out. The aim of this study was to minimize glucose degradation and acquire data to compare the effect of catalyst type on glucose degradation. The temperature range employed was from 200 to 220°C and the catalysts concentration was the same described above. First-order rate constants for hydrolysis of cellulosic pulp were obtained from linear regressions using data from weight loss. These rate constants were also used to calculate Arrhenius activation energy. The average activation energies for H2SO4 and HCl were 184.9 and 183.5 kJ/mol, respectively. The maximum glucose yields obtained in H2SO4 and HCl were 69.8% and 70.2%, respectively. First-order rate constants for glucose decomposition were also obtained from linear regressions and also used to calculate Arrhenius activation energy. The average activation energies for glucose decomposition in H2SO4 and HCl were 124.5 e 142.9 kJ/mol, respectively. From the results of kinetic studies was possible to conclude that HCl was a more efficient catalyst than H2SO4. Moreover, HCl is more expensive than H2SO4 and chloride ions are responsible for making HCl more corrosive than H2SO4

Adsorption of Cu(II), Cd(II) and Pb(II) from aqueous single metal solutions by succinylated twice-mercerized sugarcane bagasse functionalized with triethylenetetramine.

This study describes the preparation of two new chelating materials, MMSCB 3 and 5, derived fromsuccinylated twice-mercerized sugarcane bagasse (MMSCB 1). MMSCB 3 and 5 were synthesized from MMSCB 1 using two different methods as described by Gurgel and Gil (2009). In the first method MMSCB 1 was activated with 1,3-diisopropylcarbodiimide and in the second with acetic anhydride (to form an internal anhydride) and later both were reacted with triethylenetetramine in order to obtain MMSCB 3 and 5. New obtained materials were characterized by mass percent gain, concentration of amine groups, FTIR, and elemental analysis. MMSCB 3 and 5 showed mass percent gain of 19.9 and 57.1%, concentration of amine groups of 2.0 and 2.1 mmol/g, and nitrogen content of 5.8 and 4.4%. The capacity of MMSCB 3 and 5 to adsorb Cu2þ, Cd2þ, and Pb2þ from aqueous single metal ion solutions was evaluated at different contact times, pHs, and initial metal ion concentrations. Adsorption isotherms were well fitted by Langmuir model. Maximum adsorption capacities of MMSCB 3 and 5 for Cu2þ, Cd2þ, and Pb2þ were found to be 59.5 and 69.4, 86.2 and 106.4, 158.7 and 222.2 mg/g, respectively

Removal of Zn2+ from aqueous single metal solutions and electroplating wastewater with wood sawdust and sugarcane bagasse modified with EDTA dianhydride (EDTAD).

This work describes the preparation of a new chelating material derived from wood sawdust, Manilkara sp., and not only the use of a new support, but also a chemically modified sugarcane bagasse synthesized in our previous work to remove Zn2+ from aqueous solutions and electroplating wastewater. The first part describes the chemical modification of wood sawdust and sugarcane bagasse using ethylenediaminetetraacetic dianhydride (EDTAD) as modifying agent in order to introduce carboxylic acid and amine functional groups into these materials. The obtained materials such as the modified sugarcane bagasse, EB, and modified wood sawdust, ES were then characterized by infrared spectroscopy (IR) and CHN. The second part evaluates the adsorption capacity of Zn2+ by EB and ES from aqueous single metal solutions and real electroplating wastewater, which concentration was determined through direct titration with EDTA and inductively coupled plasma (ICP-OES). Adsorption isotherms were developed using Langmuir model. Zn2+ adsorption capacities were found to be 80 mg/g for ES and 105 mg/g for EB whereas for the industrial wastewater these values were found to be 47 mg/g for ES and 45 mg/g for EB. Zn2+ adsorption in the wastewater was found to be lower than in Zn2+ spiked solution due to the competition between other cations and/or interference of other ions, mainly Ca2+ and Cl− that were present in the wastewater

Adsorption of Cu(II), Cd(II), and Pb(II) from aqueous single metal solutions by sugarcane bagasse and mercerized sugarcane bagasse chemically modified with succinic anhydride.

This work describes the preparation of new chelating material from mercerized sugarcane bagasse. The first part treats the chemical modification of non-mercerized sugarcane bagasse (SCB) and twice-mercerized sugarcane bagasse (MMSCB) with succinic anhydride. Mass percent gains (mpg) and degrees of succinylation (DS) of succinylated non- and twice-mercerized sugarcane bagasse 1 (SCB 1 and MMSCB 1) were calculated. MMSCB 1 exhibited an increase in mpg and DS of 49.2% and 0.9 mmol/g in relation to SCB 1. SCB 2 and MMSCB 2 were obtained by treatment of MMSCB 1 and SCB 1 with bicarbonate solution to release the carboxylate functions and characterized by FTIR. The second part evaluates and compares the adsorption capacity of SCB 2 and MMSCB 2 for Cu2+, Cd2+ and Pb2+ ions in an aqueous single metal solution. Adsorption isotherms were developed using Langmuir model. MMSCB 2 exhibited an increase in Qmax for Cd2+ (43.6 mg/g) and Pb2+ (83.3 mg/g) in relation to SCB 2

Activated carbons from agricultural by products (pine tree and coconut shell), coal, and carbon nanotubes as adsorbents for removal of sulfamethoxazole from spiked aqueous solutions : kinetic and thermodynamic studies.

In this study, four different adsorbent materials: commercial powdered activated carbon (PAC) from pine tree (PAC-I) and coconut shell (PAC-III) agricultural crop wastes, coal (PAC-II), and carbon nanotubes (CNT) were tested and compared for the removal of sulfamethoxazole (SMX) from spiked aqueous solutions. The kinetic, extrathermodynamic, and thermodynamic parameters for the adsorption of SMX on PACs and CNT were also determined. The results indicate that PAC-I was the best adsorbent for SMX adsorption. SMX adsorption was only favorable with PAC-I and CNT, leading to Gibbs free energies in the range of −39 to −44 kJ mol−1 and showing that the adsorption process was spontaneous in all temperature ranges (15–45 ◦C) tested. Langmuir model best described SMX adsorption on PAC-I and led to maximum adsorption capacity of∼131mgg−1 (at 25 ◦C), which was∼4.6 times higher than that observed for CNT. The mechanism of SMX adsorption on PAC-I and CNT was suggested with basis on thermodynamic and extrathermodynamic parameters. The kinetic studies showed the pseudo-second-order model best described SMX adsorption, yielding k2 values of 0.0035 and 0.0016 gmg−1 min−1 for PAC-I and CNT, respectively

Enhancing liquid hot water (LHW) pretreatment of sugarcane bagasseby high pressure carbon dioxide (HP-CO2).

Liquid hot water (LHW) pretreatment associated with high pressure carbon dioxide (HP-CO2) was eval-uated as a potential green pretreatment technology for extraction of hemicelluloses from depithedsugarcane bagasse to produce fermentable sugars. Developing a technology based on the use of lowcost, non-corrosive, and recoverable chemicals as CO2can result in a more efficient and economic pro-cess. In this study, depithed sugarcane bagasse was treated with LHW and HP-CO2at milder temperaturesin comparison with LHW pretreatment alone. To assess the effects of varying pretreatment operationalconditions on extraction of xylo-oligosaccharides and xylose release with cellulose preservation a centralcomposite design (CCD) of experiments was used. The pretreatments were carried out at temperaturesranging from 93.8◦C (8.62 MPa) to 136.2◦C (12.96 MPa) and times from 17.6 to 102.4 min with a liquid-to-solid ratio of 12:1. The maximum xylan and xylose concentrations were achieved by treating depithedbagasse at 100◦C for 30 min and 115◦C for 60 min, respectively. At these conditions the amount of xylanequivalent ranged 10–12 g/L. At 115◦C for 60 min, the cellulose preservation achieved 97.2%. The obtainedresults showed that HP-CO2proved to be an efficient hydrolysis agent. Samples of LHW-HP-CO2pre-treated bagasse were tested for enzymatic digestibility. Depithed bagasse pretreated at 115◦C for 60 minafter enzymatic hydrolysis had a glucose yield of 30.43 g/L and a cellulose conversion of 41.17%

Adsorption of Cu(II), Cd(II), and Pb(II) from aqueous single metal solutions by mercerized cellulose and mercerized sugarcane bagasse chemically modified with EDTA dianhydride (EDTAD).

This work describes the preparation of new chelating materials derived from cellulose and sugarcane bagasse for adsorption of Cu2+, Cd2+, and Pb2+ ions from aqueous solutions. The first part involved the mercerization treatment of cellulose and sugarcane bagasse with NaOH 5 mol/L. Non- and mercerized cellulose and sugarcane bagasse were then reacted with ethylenediaminetetraacetic dianhydride (EDTAD) in order to prepare different chelating materials. These materials were characterized by mass percent gain, X-ray diffraction, FTIR, and elemental analysis. The second part consisted of evaluating the adsorption capacity of these modified materials for Cu2+, Cd2+, and Pb2+ ions from aqueous single metal solutions, whose concentration was determined by atomic absorption spectroscopy. These materials showed maximum adsorption capacities for Cu2+, Cd2+, and Pb2+ ions ranging from 38.8 to 92.6 mg/g, 87.7 to 149.0 mg/g, and 192.0 to 333.0 mg/g, respectively. The modified mercerized materials showed larger maximum adsorption capacities than modified non-mercerized materials