Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Cellulase Production by Aspergillus flavus Linn Isolate NSPR 101 fermented in sawdust, bagasse and corncob
Tunde Victor Ojumu, Bamidele Ogbe Solomon, Eriola Betiku, Stephen Kolawole Layokun, Bamikole Amigun
African Journal of Biotechnology , 2003,
Abstract: Bagasse, corncob and sawdust were used as lignocellulosic substrates for the production of cellulase enzyme using Aspergillus flavus after ballmilling and pretreatment with caustic soda. From the fermentation studies, sawdust gave the best result with an enzyme activity value of 0.0743IU/ml while bagasse and corncob gave 0.0573IU/ml and 0.0502IU/ml respectively. The three lignocellulosics gave their maximum enzyme activities at about the twelfth hour of cultivation, suggesting that the 12th hour is the optimum time when the enzyme may be harvested. (African Journal of Biotechnology: 2003 2(6): 150-152)
Ellen C. Giese,Robert F. H. Dekker,Aneli M. Barbosa
BioResources , 2008,
Abstract: Orange bagasse comprising pulp tissues, rind, and seeds, constitutes a major industrial food waste arising from processing oranges for juice, and represents a fermentation feedstock for the production of enzymes. Botryosphaeria rhodina MAMB-05 grown on essential oils-extracted orange bagasse in submerged (SmF) and solid-state fermentation (SSF) with and without added nutrients produced pectinase and laccase. Highest enzyme titres (pectinase, 32 U ml-1; laccase, 46 U ml-1) occurred in SSF without added nutrients, indicating nutrient sufficiency of orange bagasse at a solids concentration of 16 % (w v-1) to sustain growth and high enzyme titres. Orange essential oil extract added to nutrient medium containing 1 % glucose in SmF strongly inhibited fungal growth with consequent lower laccase and pectinase activities. The results demonstrate the need to remove the essential oils fraction before citrus waste can be successfully used as a fermentation substrate for enzyme production.
Removal of Heavy Metal Ions (Pb2+, Cu2+) in Aqueous Solutions by Pterygota macrocarpa Sawdust  [PDF]
K. Adouby,L.C. Koffi Akissi,N. Eboua Wandan,B. Yao
Journal of Applied Sciences , 2007,
Abstract: The purpose of this study is the use of Pterygota macrocarpa sawdust as adsorbent for lead and copper removal into aqueous acid solutions. The results showed that the rate of removal is better for particle sizes lower than 0.5 mm, in the metal solutions at pH 3. The Langmuir, Freundlich and Temkin isotherms studies were allowed to determine the maximum capacity of adsorption of the sawdust; it is 115.61 and 24.02 mg g-1 for the lead and cooper removal, respectively. This study also showed that the metal ions removal is accompanied by a releasing of K+, Ca2+ and Mg2+ in the metal solutions. This use could constitute a way of valorisation of the sawdust, a main waste of the wood industry.
Sorption and Desorption of Pb(II) from Aqueous Solution using Triplochiton scleroxylon Sawdust as Sorbent  [PDF]
L.C. Koffi Akissi,K. Adouby,E.N. Wandan,B. Yao
Journal of Applied Sciences , 2010,
Abstract: Studies on a batch sorption process using Triplochiton scleroxylon sawdust as a low cost sorbent produced by wood industry was investigated to remove lead ions from aqueous solution. The sorption process follows a pseudo second-order rate kinetics at different dosage of sawdust and at different Pb(II) initial concentration. The Freundlich and Langmuir sorption models were used for the mathematical description of the equilibrium and isotherm constants were also evaluated, the maximum sorption capacity of Pb(II) in single component system was determined to be 26.38 mg g-1 at 30±2°C and at an initial pH of 4. The sorption process showed that copper, cadmium or both metals in aqueous solutions suppressed the removal of lead ions by sawdust. These results indicated that ion exchange is one of the major sorption mechanisms for binding Pb(II) ions into sawdust.
Removal of heavy metals from aqueous solution by sawdust adsorption
BULUT Yasemin,TEZ Zeki,
BULUT Yasemin
,TEZ Zeki

环境科学学报(英文版) , 2007,
Abstract: The adsorption of lead, cadmium and nicel from aqueous solution by sawdust of walnut was investigated. The effect of contact time,initial metal ion concentration and temperature on metal ions removal has been studied. The equilibrium time was found to be of the order of 60 min. Kinetics fit pseudo first-order, second-order and intraparticle diffusion models, hence adsorption rate constants were calculated. The adsorption data of metal ions at temperatures of 25, 45 and 60C have been described by the Freundlich and Langmuir isotherm models. The thermodynamic parameters such as energy, entropy and enthalpy changes for the adsorption of heavy metal ions have also been computed and discussed. Ion exchange is probably one of the major adsorption mechanisms for binding divalent metal ions to the walnut sawdust. The selectivity order of the adsorbent is Pb(Ⅱ)≈Cd(Ⅱ)>Ni(Ⅱ). From these results, it can be concluded that the sawdust of walnut could be a good adsorbent for the metal ions from aqueous solutions.
Use of Sawdust of Aspen Tree for the Removal of Chromium (VI) from Aqueous Solution
M.T. Hamed Mosavian,I. Khazaei,M. Aliabadi
Iranian Journal of Earth Sciences , 2012,
Abstract: Adsorption capacity of Cr (VI) onto sawdust of aspen tree and activated sawdust, was investigated in a batch system by considering the effects of various parameters like contact time, initial concentration, pH , temperature, agitation speed, absorbent dose and particle size. Cr (VI) removal is pH dependent and caused to be maximum at pH 2.0. The amounts of Cr(VI) adsorbed increased with increase in dose of both adsorbents and their contact time. Experimental results show that the low cost biosorbent was effective for the removal of pollutants from aqueous solution. The Langmuir, Freundlich and Temkin isotherm were used to describe the adsorption equilibrium studies of agrowaste. Freundlich isotherm shows better fit than Langmuir and Temkin isotherm in the temperature range studied.
Journal of Applied Sciences in Environmental Sanitation , 2011,
Abstract: In this study the removal of cadmium and lead from aqueous solutions in batch type processes using pine sawdust as biosorbent was investigated. The kinetics and equilibrium of biosorption process were evaluated to obtain kinetic parameters and maximum biosorption capacities of the material for Cd and Pb at different temperatures. It was found that the Lagergren equation describes sorption kinetics of cadmium and lead in this material at different temperatures. In addition, biosorption isotherms of both metals are well described by the Langmuir-Freundlich equation, indicating that chemisorption mechanism on heterogenous surfaces prevails in these metal-biosorbent systems. Temperature has no significant effect on the biosorption capacities of Cd and Pb in pine sawdust, which can be considered relatively high compared to other adsorbents reported in literature.
Journal of Applied Sciences in Environmental Sanitation , 2011,
Abstract: Application of saw dust (raw and modified) was investigated for the removal of Orange G from its aqueous solutions. The raw saw dust was modified by sulphuric acid and sodium bicarbonate. The adsorbents were characterized by using sophisticated techniques like Fourier Transformation Infrared (FT-IR) Spectrometer and Scanning Electron Microscope (SEM). The physicochemical properties of the saw dusts were determined and its elemental analysis was also carried out. Equilibrium modelling of the process of removal of selected dye was carried out and the data were fitted to Langmuir and Freundlich isotherm models. Both the Langmuir and Freundlich models fitted the adsorption data properly. An appreciable adsorption capacity for the removal of Orange G by using raw and modified sawdust was observed. The maximum adsorption capacity was found to be 0.40 mgg 1 for an initial concentration of 2.5 mgL 1 of Orange G at a dose of 1.0 gL 1 of the adsorbent. Thermodynamic studies for the process of removal were carried out and the parameters namely change in free energy, enthalpy and entropy were calculated. The negative values of G, the free energy change are indicative of the spontaneous nature of the process of dye removal, whereas the value of enthalpy change H (-15.392 kJ/mol) indicate that the adsorption involves an exothermic process.
Removal of reactive dyes from aqueous solution using bagasse fly ash  [PDF]
Manaskorn Rachakornkij,Sirawan Ruangchuay,Sumate Teachakulwiroj
Songklanakarin Journal of Science and Technology , 2004,
Abstract: Bagasse fly ash, a waste from the sugar industry, was investigated as a replacement for the current expensive methods of removing reactive dyes (Remazol Black B; RBB, Remazol Brilliant Blue R; RBBR, and Remazol Brilliant Red F3B; RBRF3B) from aqueous solutions. Bagasse fly ash was collected from a local sugar factory in Saraburi province, Thailand. It was oven dried at 110oC overnight and sieved to the desired particle size of 150 μm or smaller. The 50 mL plastic conical tubes containing solution and bagasse fly ash were shaken at room temperature (27±2oC). The pH values of solutions were adjusted by addition of HNO3 and NaOH. The batch study indicated that initial pH of aqueous solutions did not affect dye removal. While the removal efficiency decreased with increasing initial concentration, it increased with increasing adsorbent concentration. The best adsorptions were obtained under condition of 50 mg/L concentration, original pH solution of about 5, and 240, 300, and 240 minutes contact time for RBB, RBBR, and RBRF3B, respectively. Most adsorption experiments showed in the range of about 50% to 98% removal; that is, the efficiencies of RBB, RBBR, and RBRF3B adsorption were found to be between 58.48-98.03%, 46.15-93.47%, and 46.30- 94.60%, respectively. For the linear and nonlinear forms of the Langmuir and Freundlich models, the results indicated that the Langmuir adsorption isotherm fitted the data better than the Freundlich adsorption isotherm. Adsorption of these dyes onto bagasse fly ash was favorable sorption. Therefore, bagasse fly ash, the low-cost agricultural waste in Thailand, is suitable for use as adsorbent for RBB, RBBR, and RBRF3B under this investigation.
Sugarcane bagasse for the removal of erythrosin B and methylene blue from aqueous waste
Pankaj Sharma,Harleen Kaur
Applied Water Science , 2011, DOI: 10.1007/s13201-011-0018-x
Abstract: Present study explores the potentiality of locally available cellulose, hemicellulose and lignin-rich agricultural by-product sugarcane bagasse (SB) for the removal of erythrosin B (EB) and methylene blue (MB) from aqueous waste. The SB has been characterized by Fourier transform infrared and scanning electron microscopy analytical techniques. Batch experiments have been carried out to determine the influence of parameters like initial dye concentration, pH of the medium, contact time between the adsorbate and adsorbent, weight of adsorbent and system temperature on the removal of EB and MB. Optimum conditions for adsorption are found to be pH 9, temperature 308 K and an equilibration time of 1 h. Under these conditions equilibrium isotherms have been analysed by Langmuir and Freundlich isotherm equations. Based on the Langmuir adsorption isotherm model, the predicted maximum monolayer adsorption capacities of SB for EB and MB are found to be 500 mg g–1 (at 328 K) and 1,000 mg g–1 (at 308 K), respectively. The separation factor reveals the favourable nature of the isotherm for the studied dyes—SB system. The thermodynamic study indicates that the adsorptions of dyes are spontaneous and endothermic process. High temperatures favour EB adsorption whereas optimum temperature for MB adsorption is 318 K.
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.