The complete procedure for the production of inulin powder from Jerusalem artichoke tubers (JAT) was investigated. The procedure consists of isolation of inulin from JAT, elimination of color from the inulin extract and solidification. Washed tubers were first sliced, dried in a 60 °C oven for 10 h and then milled and sieved into a powder. Inulin was isolated from the JAT powder by hot water extraction using an accelerated solvent extractor (ASE). The effects of temperature and time for the extraction were investigated. The highest extraction efficiency was obtained at the extraction temperature of 80 °C for 20 min. The color of the extract was eliminated using ion exchange process with diethylaminoethyl cellulose as the sorbent. The inulin powder was subsequently obtained by freeze drying. Inulin content and inulin profiles were monitored to evaluate the efficiencies of the complete procedure. The inulin content was indirectly determined by spectrophotometry from free and total fructose measurements using potassium iodide. The inulin profile was monitored using high performance anion exchange chromatography equipped with integrated pulse amperometric detection (HPAEC-PAD). The proposed method provided the inulin production yield of 92.5%. The present procedure is fast, simple and effective for production of inulin powder from JAT. In addition, infrared spectra and some physico-chemical properties of the obtained inulin powder were determined and compared with the standard inulin.

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Our purpose was to synthesize, characterize and test photodegradation of methyl orange on two catalysts containing 10 wt% titanium supported on mesoporous MCM-41 synthesized with rice husk silica. The first catalyst was Ti-RH-MCM-41 prepared by adding tetrabutyl orthotitanate (TBOT) in a synthetic gel of RH-MCM-41, and the second catalyst was TiO 2 /RH-MCM-41 prepared by grafting TBOT on the preformed RH-MCM-41. The mesoporous structures were observed on both catalysts and they had surface area of 1,073 and 1,006 m 2 /g. The Ti in Ti-RH-MCM-41 was in the form of Ti(IV) with tetrahedral geometry residing in the mesoporous structure. This form was less active for photodegradation of methyl orange than the other one. The Ti in TiO 2 /RH-MCM-41 was anatase titania with octahedral geometry located outside the mesoporous framework. This form was more an active phase for the photodegradation and the reaction parameters on this catalyst were further investigated. The optimum catalyst weight to methyl orange volume ratio was 5 g/L and the optimum initial concentration of the dye was 2.0 ppm. The degradation rate obeyed pseudo-first order and the adsorption of methyl orange on TiO 2 /RH-MCM-41 obeyed Langmuir isotherm.

Rice husk (RH) agro-waste was used as a raw material for synthesizing mesoporous molecular sieves, MCM-41. The Fe-MCM-41 was prepared by the hydrothermal technique (HT), resulting in a higher surface area and crystallinity than when prepared under ambient conditions. In addition, a hexagonal structure was clearly seen with hydrothermal technique (HT) preparation. The adsorption of arsenate by HT-Fe-MCM-41 was investigated. The factors studied affecting arsenate adsorption capacity were ferric content in MCM-41, contact time, pH of solution, and initial arsenate concentration. It was found that HT-Fe-MCM-41 at the Si/Fe mole ratio of 10 gave the highest adsorption capacity. Arsenate adsorption reached equilibrium within 4 h. The adsorption capacity of HT-Fe-MCM-41 (Si/Fe = 10) was affected by the initial pH value and the initial arsenate concentration. The adsorption capacity was highest at pH 3 and decreased thereafter with increases in the pH of solution value. The Langmuir model fit the arsenate adsorption isotherm well. The maximum adsorption capacity for arsenate was 1,111 microg g(-1).