Papers by Mohamed Sahmoune
Environmental Chemistry Letters, 2019
Thermodynamic parameters ΔG°, ΔH° and ΔS° are indicators of the possible nature of adsorption. Th... more Thermodynamic parameters ΔG°, ΔH° and ΔS° are indicators of the possible nature of adsorption. This review summarizes the thermodynamic properties of metal adsorption by green adsorbents. Conclusively, the adsorption of heavy metals ions by green adsorbents is spontaneous in most cases (ΔG° < 0). Since the thermodynamic parameters were evaluated from very different adsorbent/adsorbate combinations, it is not possible to note a correlation between the corresponding enthalpy change (ΔH°) and entropy change (ΔS°) following adsorption.
Microchemical Journal, 2018
The removal of heavy metals by Streptomyces rimosus has been the subject of many investigations. ... more The removal of heavy metals by Streptomyces rimosus has been the subject of many investigations. This review paper focuses on the removal of heavy metals from aqueous solution through Streptomyces rimosus, produced from pharmaceutical industry as solid waste, as adsorbent, and discusses the effect of various process parameters like pH, temperature, metal concentration etc, on the metal removal efficiency of this bacterium. The paper also evaluates the different kinetic, equilibrium, and thermodynamic models used in Streptomyces rimosus sorption of heavy metals. Biomass characterization and sorption mechanisms as well as elution of metal ions are also discussed. The literature revealed that Streptomyces rimosus had a good affinity for binding lead and iron compared with other heavy metals. The adsorption of heavy metals is well described by Langmuir isotherm, which expresses the existence of monolayer adsorption. The kinetic data followed both pseudo first order and pseudo second order models. Thermodynamic studies showed spontaneous and exothermic nature of the sorption processes in most case. Dilute acids (HCl and H2SO4) are quite effective in desorption of heavy metals. Ion exchange played the chief role in the adsorption mechanism of metal, and carboxyl groups are mainly involved in this mechanism.
Desalination and Water Treatment, 2016
AbstractSawdust is abundantly available from the timber and forest industry and has been studied ... more AbstractSawdust is abundantly available from the timber and forest industry and has been studied in recent past as an adsorbent. This paper reviews the reported work on the uptake of dyes and heavy metals by natural and modified sawdust during the last 10 years. Research works examine the performance of isotherm models against the experimental equilibrium data, and an attempt has been made to discuss the kinetics of adsorption of metal ions and dyes on various sawdust materials on the basis of published report. Regeneration of sawdust materials has also been reviewed. It is found that pine, beech and mansonia sawdust are the most extensively studied adsorbents, whereas Pb2+ and methylene blue are the most efficiently removed pollutants, the Langmuir and Freundlich adsorption isotherms provide the best fit in most of the cases, and in general, pseudo-second-order kinetics is followed. There are very limited column studies and no report on commercial plant. Sawdust has a great potential in the wastewater tr...
Chemical Engineering & Technology, 2016
Arsenic contamination in water causes many diseases. Therefore, various biosorbent materials have... more Arsenic contamination in water causes many diseases. Therefore, various biosorbent materials have been tested for their ability to remove the two inorganic arsenic species commonly found in water, namely, arsenite As(III) and arsenate As(V). The arsenic biosorption is influenced by the pH value of the aqueous phase, arsenic concentration, presence of competing ions, and arsenic speciation. The biosorption kinetics of As(III) and As(V) has been reported to be rapid, with more than 80 % biosorption occurring during the first hour, followed by a second step which may take up to several hours. The pseudo‐second‐order model provided the best fit, which corresponds to a chemisorption process. The Langmuir model indicated that most arsenic ions are adsorbed in monolayer form and removal is better for As(III) than for As(V).
Desalination and Water Treatment, 2014
AbstractThe adsorption of diazinon on bentonite acid treated with dilute H2SO4 solutions has been... more AbstractThe adsorption of diazinon on bentonite acid treated with dilute H2SO4 solutions has been studied. Bentonite activated with 0.06 N sulfuric acid showed a higher efficiency in removing diazinon from aqueous solutions and was selected for further investigation. The effect of initial diazinon concentration, contact time, pH, and adsorbent dosage on the adsorption was studied in a batch mode process. Equilibrium data were analyzed by the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevitch isotherm models. Langmuir isotherm provided the best fit to the equilibrium data with maximum adsorption capacity of 5.56 mg/g. The kinetic data were found to follow closely the pseudo-second-order model. The sorption process was found to be controlled by both film and pore diffusion with film diffusion at the earlier stages followed by pore diffusion at the later stages. Thermodynamics studies revealed the spontaneous and exothermic nature of the sorption process.
Environmental Progress & Sustainable Energy, 2011
Adsorption kinetic and equilibrium studies of cationic dye namely, Astrazon Yellow (AY) from aque... more Adsorption kinetic and equilibrium studies of cationic dye namely, Astrazon Yellow (AY) from aqueous solution at various initial dye concentration (15–50 mg/L), pH (2–9), particle size <1600 μm on Aleppo pine‐tree sawdust were investigated in a batch mode operation.Batch adsorption studies revealed that the potential of Aleppo pine‐tree sawdust in dye removal was dependant on initial pH and initial dye concentration.To select the main rate‐limiting step in the overall uptake mechanism, a single external mass transfer diffusion model, Urano and Tachikawa model, and intraparticle diffusion model were used. The external mass transfer rate constant β was found to be 8.5 × 10−5 m−1 at initial concentration 50mg/L of AY and 1.14 × 10−4 m−1 at initial concentration 15 mg/L of AY. The multilinearity obtained in the intraparticle diffusion plot showed that both film diffusion and pore diffusion are important in controlling the overall adsorption rate. The effective diffusion coefficients ...
Open Chemistry, 2013
Heavy metals, derived from industrial wastewater discharge, present a serious threat to human hea... more Heavy metals, derived from industrial wastewater discharge, present a serious threat to human health and to natural water. Biosorption is regarded as a cost-effective biotechnology for the treatment of high volume and low concentration wastewaters containing heavy metal(s) in the order of 1 to 100 mg L−1. Among the biomaterials for heavy metal removal which have been researched during the past decades is the Streptomyces species, a by-product of an industrial antibiotic fermentation process. This paper describes the hazards posed by heavy metals effluents on the environment and use of various Streptomyces species to remove heavy metals from aqueous solution. Characterization of Streptomyces species, factors affecting biosorption, biosorption isotherms and biosorption kinetics is discussed. Graphical abstract
Biomass waste, mainly Streptomyces rimosus is generated from large scale antibiotic industry. In ... more Biomass waste, mainly Streptomyces rimosus is generated from large scale antibiotic industry. In this study activated S. rimosus biomass was evaluated as biosorbent for the removal chromium from tannery waste water. As Cr were bound to the biomass. The solution pH decreased, indicating that 3+ proton in the biomass was exchanged with chromium ion. The streptomyces rimosus bound Cr at up to 3+ 65 mg/g at pH 4.8, where chromium does not precipitate. Reusability of biomass was examined by the 24 desorption studies, in which H SO eluted 95 % chromium. The rate of elimination of the chromium in the effluent of the tannery is about 83% after the sixteenth cycle.
Toxicological & Environmental Chemistry, Oct 1, 2009
Environmental progress & sustainable energy, Aug 24, 2011
Adsorption kinetic and equilibrium studies of cationic dye namely, Astrazon Yellow (AY) from aque... more Adsorption kinetic and equilibrium studies of cationic dye namely, Astrazon Yellow (AY) from aqueous solution at various initial dye concentration (15-50 mg/L), pH (2-9), particle size <1600 lm on Aleppo pine-tree sawdust were investigated in a batch mode operation. Batch adsorption studies revealed that the potential of Aleppo pine-tree sawdust in dye removal was dependant on initial pH and initial dye concentration. To select the main rate-limiting step in the overall uptake mechanism, a single external mass transfer diffusion model, Urano and Tachikawa model, and intraparticle diffusion model were used. The external mass transfer rate constant b was found to be 8.5 3 10 25 m 21 at initial concentration 50 mg/L of AY and 1.14 3 10 24 m 21 at initial concentration 15 mg/L of AY. The multilinearity obtained in the intraparticle diffusion plot showed that both film diffusion and pore diffusion are important in controlling the overall adsorption rate. The effective diffusion coefficients D i were found to be 3.88 3 10 211 cm 2 /s and 4.2 3 10 211 cm 2 /s for initial concentration of AY of 15 mg/L and 50 mg/L, respectively, indicating that intraparticle diffusion may not be the sole dominating factor controlling the mechanism of the process into Aleppo pine-tree sawdust. AY sorption onto sawdust was mainly located on the surface. The equilibrium isotherms were analyzed using the Langmuir, Freundlich, Temkin, and Elovich models. It was seen that the sorption data fitted to Langmuir, Freundlich, Temkin, and the Elovich isotherms, but they were very well described by the Langmuir model.
International Journal of Chemical Reactor Engineering, Nov 23, 2010
This paper aims to investigate the sorption of Astrazon yellow (A.Y.) onto sawdust (Aleppo pine t... more This paper aims to investigate the sorption of Astrazon yellow (A.Y.) onto sawdust (Aleppo pine tree), a forest waste as that acts as a low-cost adsorbent. In our experiments, the batch sorption is studied with respect to solute concentration, contact time, adsorbent dose, particle size and pH. The adsorption process attains equilibrium within 300 minutes. The extent of dye removal decreased with increasing particle size and increased with increasing contact time, adsorbent dose and pH. The equilibrium data were analysed by the Langmuir and Freundlich isotherms. The characteristic parameters for each isotherm were determined. By considering the experimental results and adsorption models applied in this study, it can be concluded that equilibrium data were represented well by the Langmuir isotherm equation. Maximum adsorption capacity calculated at 293K was 81.8 mg/g. Five kinetic models (pseudo-first order, pseudo-second order, fractional power, Elovich and intraparticle diffusion kinetic equations) were used to predict the adsorption rate constants. The kinetics of adsorption of the basic dye followed both Elovich and pseudo-second order kinetics, and intraparticle diffusion was not the sole rate-controlling step. The effective diffusion of Astrazon yellow in sawdust according to Boyd Model was 24.22 .10-12 m2/S. In order to reveal the adsorption characteristic of sawdust samples, SEM and FTIR spectra analyses were carried out. The results show that sawdust (Aleppo pine tree) can be an alternative low-cost adsorbent for removing cationic dyes from wastewater.
Environmental chemistry for a sustainable world, 2018
There is growing interest in the use of cheap organic materials to clean heavy metal pollution by... more There is growing interest in the use of cheap organic materials to clean heavy metal pollution by adsorption. This chapter presents the thermodynamic parameters of the adsorption of heavy metals ions adsorption by green adsorbents: the Gibbs free energy, entropy, and enthalpy. Research indicates that the temperature of the adsorption medium is the most important parameter influencing thermodynamic analysis. As a result, the adsorption of heavy metals ions by green adsorbents is spontaneous in most cases, with ΔG lower than 0. Some researchers found that the uptake of heavy metals ions increased with temperature, an endothermic process. A more enhanced level of uptake in parallel with a temperature rise resembles the nature of a chemisorption mechanism, with ΔH higher than 0. In contrast, other authors obtained the opposite trends, with ΔH lower than 0, low temperature caused a high adsorption (exothermic process), and the mechanism was mainly physical adsorption. Some authors reported positive ΔS values for adsorption of heavy metals ions by green adsorbents, suggesting the affinity of metals ions for adsorbents
Chemical Engineering & Technology, Aug 15, 2016
Arsenic contamination in water causes many diseases. Therefore, various biosorbent materials have... more Arsenic contamination in water causes many diseases. Therefore, various biosorbent materials have been tested for their ability to remove the two inorganic arsenic species commonly found in water, namely, arsenite As(III) and arsenate As(V). The arsenic biosorption is influenced by the pH value of the aqueous phase, arsenic concentration, presence of competing ions, and arsenic speciation. The biosorption kinetics of As(III) and As(V) has been reported to be rapid, with more than 80 % biosorption occurring during the first hour, followed by a second step which may take up to several hours. The pseudo‐second‐order model provided the best fit, which corresponds to a chemisorption process. The Langmuir model indicated that most arsenic ions are adsorbed in monolayer form and removal is better for As(III) than for As(V).
Desalination and Water Treatment, Jan 13, 2016
AbstractSawdust is abundantly available from the timber and forest industry and has been studied ... more AbstractSawdust is abundantly available from the timber and forest industry and has been studied in recent past as an adsorbent. This paper reviews the reported work on the uptake of dyes and heavy metals by natural and modified sawdust during the last 10 years. Research works examine the performance of isotherm models against the experimental equilibrium data, and an attempt has been made to discuss the kinetics of adsorption of metal ions and dyes on various sawdust materials on the basis of published report. Regeneration of sawdust materials has also been reviewed. It is found that pine, beech and mansonia sawdust are the most extensively studied adsorbents, whereas Pb2+ and methylene blue are the most efficiently removed pollutants, the Langmuir and Freundlich adsorption isotherms provide the best fit in most of the cases, and in general, pseudo-second-order kinetics is followed. There are very limited column studies and no report on commercial plant. Sawdust has a great potential in the wastewater tr...
Desalination and Water Treatment, Nov 3, 2014
AbstractThe adsorption of diazinon on bentonite acid treated with dilute H2SO4 solutions has been... more AbstractThe adsorption of diazinon on bentonite acid treated with dilute H2SO4 solutions has been studied. Bentonite activated with 0.06 N sulfuric acid showed a higher efficiency in removing diazinon from aqueous solutions and was selected for further investigation. The effect of initial diazinon concentration, contact time, pH, and adsorbent dosage on the adsorption was studied in a batch mode process. Equilibrium data were analyzed by the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevitch isotherm models. Langmuir isotherm provided the best fit to the equilibrium data with maximum adsorption capacity of 5.56 mg/g. The kinetic data were found to follow closely the pseudo-second-order model. The sorption process was found to be controlled by both film and pore diffusion with film diffusion at the earlier stages followed by pore diffusion at the later stages. Thermodynamics studies revealed the spontaneous and exothermic nature of the sorption process.
83 p. : ill. ; 30 cmIl existe des quantités importantes de biomasses qui n’ont pas trouvé jusqu’à... more 83 p. : ill. ; 30 cmIl existe des quantités importantes de biomasses qui n’ont pas trouvé jusqu’à présent des valorisations intéressantes et qui sont capable d’adsorber naturellement des éléments toxiques, telle que le Chrome. Il s’agit de résidus de la fermentation industrielle productrice d’antibiotiques, d’enzymes, de vitamines ou d’acide organique. Ces biosorbants pouvant être régénères, s’avèrent sélectifs, performants et très économiques. Leurs utilisations semblent particulièrement intéressantes dans la détoxication des eaux usées riche en Chrome. Dans le but de protéger l’environnement, nous devons trouver des solutions pour l’élimination de substances polluantes telles que le Chrome rejetés par l’industrie de la tannerie. C’est dans cet esprit que nous avons utilisés une biomasse morte Streptomycesrimosus pour l’élimination du Chrome trivalent. Notre recherche a pour but de valoriser un produit secondaire (la biomasse) issu d’un processus de fabrication des antibiotiques, e...
Environmental Chemistry for a Sustainable World, 2018
There is growing interest in the use of cheap organic materials to clean heavy metal pollution by... more There is growing interest in the use of cheap organic materials to clean heavy metal pollution by adsorption. This chapter presents the thermodynamic parameters of the adsorption of heavy metals ions adsorption by green adsorbents: the Gibbs free energy, entropy, and enthalpy. Research indicates that the temperature of the adsorption medium is the most important parameter influencing thermodynamic analysis. As a result, the adsorption of heavy metals ions by green adsorbents is spontaneous in most cases, with ΔG lower than 0. Some researchers found that the uptake of heavy metals ions increased with temperature, an endothermic process. A more enhanced level of uptake in parallel with a temperature rise resembles the nature of a chemisorption mechanism, with ΔH higher than 0. In contrast, other authors obtained the opposite trends, with ΔH lower than 0, low temperature caused a high adsorption (exothermic process), and the mechanism was mainly physical adsorption. Some authors reported positive ΔS values for adsorption of heavy metals ions by green adsorbents, suggesting the affinity of metals ions for adsorbents
International Journal of Environmental Research, 2009
In the present investigation, dead bacterium biomass Streptomyces rimosus was used as an inexpens... more In the present investigation, dead bacterium biomass Streptomyces rimosus was used as an inexpensive and efficient biosorbent for Cr (III) removal from aqueous solution. The bacterial biomass was treated with 0.1 M NaOH. Sorption level of 65 mg/g was observed at pH 4.8 while precipitation effect augmented this value at higher pH range. Chromium desorption increased with decreasing desorption agents pH (including HCl and H2SO4) to a maximum value of 95% at approximately zero pH. Langmuir, Freundlich and Temkin models were applied to describe the biosorption isotherm of the metal ions by Streptomyces rimosus biomass. Langmuir model fitted the equilibrium data better than the Freundlich isotherm. Maximum metal uptake qmax was observed as 83.33 mg gâ€1 indicate good biosorbents than other biomass. Experimental data were also tested in terms of biosorption kinetics using fractional power, Elovich, pseudo-first order and pseudo-second order rate expressions. The results showed that the b...
ةـصلاخلا : نإ يف ةمهاسم وه لمعلا اذه ايم ةجلاعم تايلمع مادختسا ه ةفلكلا ةيلاعفو ةيعيبطلا يحصلا فر... more ةـصلاخلا : نإ يف ةمهاسم وه لمعلا اذه ايم ةجلاعم تايلمع مادختسا ه ةفلكلا ةيلاعفو ةيعيبطلا يحصلا فرصلا ، و ةصاخب ةغابدلا ةعانص نم ةجتانلا كلت . ةيموثرجلا هتيملا ةداملا نإ ) RIMOSUS STREPTOMYCES ( يتلا اهرابتخا مت دق ةيويحلا تاداضملا جاتنإ تاطحم نم تافلخمآ اهعيمجت مت ازتماآ يثلاثلا موركلل ز . دقو أ براقت يطعي ءوفاكتلا يسادس موركلا نويا نأ جئاتنلا ترهظ ا ديج ا ةيوضعلا ةلتكلل ةبسنلاب . ىلع لوصحلا مت دقو أ ءاد أ لضف دنع يثلاثلا موركلل يضمحلا ينيجورديهلا مقرلا يوقلا PH ) ح يلاو 4.8 ( عفدلا ماظن يف كلذو . إو ةمساحلا ةيسيئرلا ةوطخلا ن يتلا حت ةيآرح يه زازتملاا ةآرح نم د تاذ ةفئازلا صاصتملاا لأا جذومن راشتنلاا ةقبطو يئانثلا . دقو نم ىلعأ تناآو زازتمأ ةءافآ ىلعأ ىلع لوصحلا مت 82 mg.g تافشر ةجزمن قيبطتب كلذو لأا مرتوسي .
International Journal of Chemical Reactor Engineering, 2010
This paper aims to investigate the sorption of Astrazon yellow (A.Y.) onto sawdust (Aleppo pine t... more This paper aims to investigate the sorption of Astrazon yellow (A.Y.) onto sawdust (Aleppo pine tree), a forest waste as that acts as a low-cost adsorbent. In our experiments, the batch sorption is studied with respect to solute concentration, contact time, adsorbent dose, particle size and pH. The adsorption process attains equilibrium within 300 minutes. The extent of dye removal decreased with increasing particle size and increased with increasing contact time, adsorbent dose and pH. The equilibrium data were analysed by the Langmuir and Freundlich isotherms. The characteristic parameters for each isotherm were determined. By considering the experimental results and adsorption models applied in this study, it can be concluded that equilibrium data were represented well by the Langmuir isotherm equation. Maximum adsorption capacity calculated at 293K was 81.8 mg/g. Five kinetic models (pseudo-first order, pseudo-second order, fractional power, Elovich and intraparticle diffusion k...
Uploads
Papers by Mohamed Sahmoune