A facile one-step co-precipitation method was demonstrated to fabricate amorphous sulfurcontaining calcium phosphate （SCP） nanoparticles, in which the sulfur group was in-situ introduced into calcium phosphate. The ...A facile one-step co-precipitation method was demonstrated to fabricate amorphous sulfurcontaining calcium phosphate （SCP） nanoparticles, in which the sulfur group was in-situ introduced into calcium phosphate. The resulting SCP exhibited a noticeable enhanced performance for Pb（II） removal in comparison with hydroxyapatite （HAP）, being capable of easily reducing 20 ppm of Pb（II） to below the acceptable standard for drinking water within less than 10 min. Remarkably, the saturated removal capacities of Pb（II） on SCP were as high as 1720.57 mg/g calculated by the Langmuir isotherm model, exceeding largely that of the previously reported absorbents. Significantly, SCP displayed highly selective removal ability toward Pb（II） ions in the presence of the competing metal ions （Ni（II）, Co（II）, Zn（II）, and Cd（II））. Further investigations indicated that such ultra-high removal efficiency and preferable affinity of Pb（II） ions on SCP may be reasonably ascribed to the formation of rodlike hydroxypyromorphite crystals on the surface of SCP via dissolution-precipitation and ion exchange reactions, accompanied by the presence of lead sulfide precipitates. High removal efficiency, fast removal kinetics and excellent selectivity toward Pb（II） made the obtained SCP material an ideal candidate for Pb（II） ions decontamination in practical application.展开更多
Oxygenation constants and thermodynamic parameters DeltaH degrees and DeltaS degrees of cobalt (II) complexes with bis-(furaldehyde) Schiff bases (1, 2, 3, 4)were obtained by mearsuring saturated dioxygen uptake of th...Oxygenation constants and thermodynamic parameters DeltaH degrees and DeltaS degrees of cobalt (II) complexes with bis-(furaldehyde) Schiff bases (1, 2, 3, 4)were obtained by mearsuring saturated dioxygen uptake of these complexes in pyridine at different temperature. These complexes could activate molecular oxygen and were used as catalysts in cyclohexene oxidation. The influence of ligand structure on the dioxygen affinity and catalytic activity of the complexes were discussed.展开更多
In the present study we reported the feasibility of the Anethum graveolens as biosorbent to remove Pb(II) from aqueous solutions. Anethum graveolens was characterized by scanning electron microscopy and elemental anal...In the present study we reported the feasibility of the Anethum graveolens as biosorbent to remove Pb(II) from aqueous solutions. Anethum graveolens was characterized by scanning electron microscopy and elemental analysis. The ability of Anethum graveolens to adsorb Pb(II) was investigated by using batch adsorption procedure. The effects such as pH, contact time, adsorbate concentration and biosorbent dosage on the adsorption capacity were studied. The experimental data were analysed using various adsorption kinetic models viz., the pseudo-first and second-order equations, Bangham’s equation, intraparticle diffusion and Elovich models. Results show that the pseudo-second-order equation provides the best correlation for the biosorption process. The equilibrium nature of Pb(II) adsorption at 30℃ has been described by the Langmuir, Freundlich, Temkin and Redlich-Peterson isotherm models. The equilibrium data fit well on Langmuir isotherm. The monolayer adsorption capacity of Pb(II) onto Anethum graveolens as obtained from Langmuir isotherm at 30℃ was found to be 303 mg/g. This high adsorption capacity of Anethum graveolens places this biosorbent as one of the best adsorbents for removal of Pb(II) from aqueous effluents.展开更多
In this research dobera leaves (DL), an agricultural waste, available in large quantity in south region of Saudi Arabia, were used as low-cost adsorbent for removal of metal ions such as Pb(II). Batch operation was us...In this research dobera leaves (DL), an agricultural waste, available in large quantity in south region of Saudi Arabia, were used as low-cost adsorbent for removal of metal ions such as Pb(II). Batch operation was used to study the equilibrium behavior of DL. The effects of initial concentration of Pb(II), solution pH, contact time and adsorbent dose were evaluated. To study the kinetics of adsorption of Pb(II) onto DL, pseudo-first-order, pseudo-second-order and intra-particle diffusion were used. Adsorption process undergoes pseudo-second-order kinetic as proved by the high value of R2. Furthermore, to design the equilibrium data of adsorption of process, four adsorption isotherm models such as Langmuir, Freundlich Temkin and Dubinin-Radushkevich (D-R) were used. It is found that Langmuir equation has the highest value of R2 (0.999) compared with other models. In presences of a mixture of Pb(II)/Ni(II), DL were found to be selective for Pb(II) ions with a high adsorptive capacity of 83 mg/g and show favorable adsorption with RL < 1. In addition, preliminary results indicate that DL are very effective adsorbent for the removal of Pb(II) ions (>90%) from drinking water with less competition of other ions present in water.展开更多
This work examined the removal of Pb(II) using a chitosan derivative (SB, synthesized from benzaldehyde) assisted by a magnetic field. The adsorption capacity for Pb(II) was investigated. It was found that 1) the pH a...This work examined the removal of Pb(II) using a chitosan derivative (SB, synthesized from benzaldehyde) assisted by a magnetic field. The adsorption capacity for Pb(II) was investigated. It was found that 1) the pH and concentration of the ion solution, as well as exposure time and strength of magnetic field, affected the degree of adsorption;and 2) studies of the adsorption isotherms and kinetics of ions onto SB revealed that SB showed enhanced adsorption capacity towards Pb(II) ions in a magnetic field compared with magnetically untreated samples. The Langmuir and Freundlich isotherm were applied to describe the experimental adsorption, and the maximum adsorption capacity of SB for Pb(II) was 2.5040 mg/g, when assisted by a magnetic field of 480 kA/m.展开更多
Dissolved organic matter(DOM)plays a vital role in promoting carbon and nutrient cycling.It is a food source for organisms and controls the migration and transformation of trace metals and other contaminants in aquati...Dissolved organic matter(DOM)plays a vital role in promoting carbon and nutrient cycling.It is a food source for organisms and controls the migration and transformation of trace metals and other contaminants in aquatic systems.The contributions of aquatic DOM to the environment and ecology of a system are closely related to its abundance and chemical structure.In this study,the chemical composition and binding properties of DOM in a hypersaline lake watershed were investigated for the fi rst time using dissolved organic carbon(DOC)analysis,absorption spectroscopy,Fourier transform infrared spectroscopy,pyrolysis-GC-MS(Py-GC-MS),and fl uorescence parallel factor(PARAFAC)analysis combined with Pb(II)titration techniques.The results showed that DOM from the tributaries that fl owed into the lake had a lower DOC content,higher molecular weight,and higher specifi c UV absorbance than the DOM in lake water.Protein-like fl uorophores were mainly found in tributary and lake surface water DOM(LSDOM)and humic-like substances were abundant in lake groundwater DOM(LGDOM).Using this multi-methodological approach,we found that the DOM from the hypersaline lake watershed was mainly from microbial origins,and consisted of aromatics,carbohydrates,and aliphatics.The results from quantitative analysis showed that DOM from the infl owing tributaries contained more aromatics,lower carbohydrates,and lower aliphatics than DOM in the lake.Monocyclic aromatic hydrocarbons and carbohydrates were more abundant in LSDOM than LGDOM.The results from the Pb(II)titration technique coupled with PARAFAC analysis suggested that PARAFAC-derived components had relatively low condition stability constants(log K_(M)<2).Of the two types of lake DOM,the LGDOM had a higher Pb(II)binding potential than the LSDOM.From this study we have improved our understanding of how DOM within a hypersaline lake watershed varies in its composition and potential to bind with metals.展开更多
Chemical compositions of natural zeolites, porcelanite (opal-CT) and local sands were determined by X-ray fluorescence (XRF) and correlated with their Pb(II) removal efficiencies. Zeolites and porcelanite were from th...Chemical compositions of natural zeolites, porcelanite (opal-CT) and local sands were determined by X-ray fluorescence (XRF) and correlated with their Pb(II) removal efficiencies. Zeolites and porcelanite were from the Mikawer, Aritain and Hannon areas in Jordan. Sands (white, red and yellow) were from the United Arab Emirates (UAE). The effect of Pb(II) concentration and zeolite dosage on removal efficiency was investigated at 25.0°C using the batch equilibrium method. Commercial kaolinite, silica and alumina were also studied for comparison. Removal efficiencies, in mg Pb(II)/g adsorbent, were: 76.9, 52.7 and 42.1 for Hannon, Mikawer and Aritain zeolites, respectively;58.2 for porcelanite;29.7, 11.0 and 8.5 for yellow, red and white sand, respectively;7.2, 3.3 and 1.3 for kaolinite, silica and alumina, respectively. XRF data indicate that adsorbents with intermediate molar ratios of Si/Al, in the range 2.70 - 2.93, are most efficient in Pb(II) removal. Scanning electron microscope (SEM) images of adsorbents suggest that morphology, in addition to chemical composition, plays a key role. In particular, a combination of factors, including shapes and sizes of crystals, channels in zeolites and pores in porcelanite, appear to favor removal of Pb(II).展开更多
Antimony(Sb)is a toxic and carcinogenic element that often enters soil in the form of antimony trioxide(Sb_(2)O_(3))and coexists with manganese(Mn)in weakly alkaline conditions.Mn oxides such as birnessite have been f...Antimony(Sb)is a toxic and carcinogenic element that often enters soil in the form of antimony trioxide(Sb_(2)O_(3))and coexists with manganese(Mn)in weakly alkaline conditions.Mn oxides such as birnessite have been found to promote the oxidative dissolution of Sb_(2)O_(3),but few researches concerned the co-transformations of Sb_(2)O_(3) and Mn(II)in environment.This study investigated themutual effect of abiotic oxidation of Mn(II)and the coupled oxidative dissolution of Sb_(2)O_(3).The influencing factors,such as Mn(II)concentrations,pH and oxygen were also discussed.Furthermore,their co-transformed mechanism was also explored based on the analysis of Mn(II)oxidation products with or without Sb_(2)O_(3) using XRD,SEM and XPS.The results showed that the oxidative dissolution of Sb_(2)O_(3) was enhanced under higher pH and higher Mn(II)loadings.With a lower Mn(II)concentration such as 0.01 mmol/L Mn(II)at pH 9.0,the improved dissolution of Sb_(2)O_(3) was attributed to the generation of dissolved intermediate Mn(III)species with strong oxidation capacity.However,under higher Mn(II)concentrations,both amorphous Mn(III)oxides and intermediate Mn(III)species were responsible for promoting the oxidative dissolution of Sb_(2)O_(3).Most released Sb(∼72%)was immobilized by Mn oxides and Sb(V)was dominant in the adsorbed and dissolved total Sb.Meanwhile,the presence of Sb_(2)O_(3) not only inhibited the removal of Mn(II)by reducing Mn(III)to Mn(II)but also affected the final products of Mn oxides.For example,amorphous Mn oxides were formed instead of crystalline Mn(III)oxides,such as MnOOH.Furthermore,rhodochrosite(MnCO_(3))was formed with the high Mn(II)/Sb_(2)O_(3) ratio,but without being observed in the low Mn(II)/Sb_(2)O_(3) ratio.The results of study could help provide more understanding about the fate of Sb in the environment and the redox transformation of Mn.展开更多
Influence of Hg(II) and Pb(II) ions on C-Phycocyanin (C-PC) from cyanobacteria Spirulina platensis was investigated using Fluorescence spectroscopy. Fluorescence measurements demonstrate quenching of C-PC emission by ...Influence of Hg(II) and Pb(II) ions on C-Phycocyanin (C-PC) from cyanobacteria Spirulina platensis was investigated using Fluorescence spectroscopy. Fluorescence measurements demonstrate quenching of C-PC emission by Hg(II) and Pb(II), and blue shifts in the fluorescence spectra. The effect of DNA on the fluorescence of Hg(II)-and Pb(II)-C-PC (from Spirulina platensis) complexes was also studied. It was shown that the fluorescence intensity of Hg-C-PC after addition of DNA gave rise to the fluorescence buildup. At the same time, addition of DNA to the Pb(II)-C-PC complexes showed no such effect. In the case of Hg(II)-C-PC, fluorescence intensity significantly decreases in time, while for Pb(II)-C-PC, decrease of the fluorescence intensity is not significant, but blue shift of the peak takes place.展开更多
In this study, the modified rice bran was tested to remove Pb(II) from water. Batch experiments were carried out to evaluate the adsorption characteristics of the modified rice bran for Pb(II) removal from aqueous sol...In this study, the modified rice bran was tested to remove Pb(II) from water. Batch experiments were carried out to evaluate the adsorption characteristics of the modified rice bran for Pb(II) removal from aqueous solutions. The adsorption isotherms, thermodynamic parameters, kinetics, pH effect, and desorbability were examined. The results show that the maximum adsorption capacity of the modified rice bran was approximately 70.8 mg Pb(II)/g absorbent at temperature of 25℃ and at the initial Pb(II) concentration of 400 mg/L and pH 7.0. And the adsorption isotherm data could be well fitted by both Langmuir equation and Freundlich equation. Thermodynamic studies confirmed that the process was spontaneous and endothermic. The adsorbed amounts of Pb(II) tend to increase with the increase of pH. The adsorption kinetic data can be satisfactorily described by either of the power functions and simple Elovich equations. The desorbability of Pb(II) is about 15-20%, and it is relatively difficult for the adsorbed Pb(II) to be desorbed. The relatively low cost and high capabilities of the rice bran make it potentially attractive adsorbent for the removal of Pb(II) from wastewater.展开更多
文摘A facile one-step co-precipitation method was demonstrated to fabricate amorphous sulfurcontaining calcium phosphate （SCP） nanoparticles, in which the sulfur group was in-situ introduced into calcium phosphate. The resulting SCP exhibited a noticeable enhanced performance for Pb（II） removal in comparison with hydroxyapatite （HAP）, being capable of easily reducing 20 ppm of Pb（II） to below the acceptable standard for drinking water within less than 10 min. Remarkably, the saturated removal capacities of Pb（II） on SCP were as high as 1720.57 mg/g calculated by the Langmuir isotherm model, exceeding largely that of the previously reported absorbents. Significantly, SCP displayed highly selective removal ability toward Pb（II） ions in the presence of the competing metal ions （Ni（II）, Co（II）, Zn（II）, and Cd（II））. Further investigations indicated that such ultra-high removal efficiency and preferable affinity of Pb（II） ions on SCP may be reasonably ascribed to the formation of rodlike hydroxypyromorphite crystals on the surface of SCP via dissolution-precipitation and ion exchange reactions, accompanied by the presence of lead sulfide precipitates. High removal efficiency, fast removal kinetics and excellent selectivity toward Pb（II） made the obtained SCP material an ideal candidate for Pb（II） ions decontamination in practical application.
文摘Oxygenation constants and thermodynamic parameters DeltaH degrees and DeltaS degrees of cobalt (II) complexes with bis-(furaldehyde) Schiff bases (1, 2, 3, 4)were obtained by mearsuring saturated dioxygen uptake of these complexes in pyridine at different temperature. These complexes could activate molecular oxygen and were used as catalysts in cyclohexene oxidation. The influence of ligand structure on the dioxygen affinity and catalytic activity of the complexes were discussed.
文摘In the present study we reported the feasibility of the Anethum graveolens as biosorbent to remove Pb(II) from aqueous solutions. Anethum graveolens was characterized by scanning electron microscopy and elemental analysis. The ability of Anethum graveolens to adsorb Pb(II) was investigated by using batch adsorption procedure. The effects such as pH, contact time, adsorbate concentration and biosorbent dosage on the adsorption capacity were studied. The experimental data were analysed using various adsorption kinetic models viz., the pseudo-first and second-order equations, Bangham’s equation, intraparticle diffusion and Elovich models. Results show that the pseudo-second-order equation provides the best correlation for the biosorption process. The equilibrium nature of Pb(II) adsorption at 30℃ has been described by the Langmuir, Freundlich, Temkin and Redlich-Peterson isotherm models. The equilibrium data fit well on Langmuir isotherm. The monolayer adsorption capacity of Pb(II) onto Anethum graveolens as obtained from Langmuir isotherm at 30℃ was found to be 303 mg/g. This high adsorption capacity of Anethum graveolens places this biosorbent as one of the best adsorbents for removal of Pb(II) from aqueous effluents.
文摘In this research dobera leaves (DL), an agricultural waste, available in large quantity in south region of Saudi Arabia, were used as low-cost adsorbent for removal of metal ions such as Pb(II). Batch operation was used to study the equilibrium behavior of DL. The effects of initial concentration of Pb(II), solution pH, contact time and adsorbent dose were evaluated. To study the kinetics of adsorption of Pb(II) onto DL, pseudo-first-order, pseudo-second-order and intra-particle diffusion were used. Adsorption process undergoes pseudo-second-order kinetic as proved by the high value of R2. Furthermore, to design the equilibrium data of adsorption of process, four adsorption isotherm models such as Langmuir, Freundlich Temkin and Dubinin-Radushkevich (D-R) were used. It is found that Langmuir equation has the highest value of R2 (0.999) compared with other models. In presences of a mixture of Pb(II)/Ni(II), DL were found to be selective for Pb(II) ions with a high adsorptive capacity of 83 mg/g and show favorable adsorption with RL < 1. In addition, preliminary results indicate that DL are very effective adsorbent for the removal of Pb(II) ions (>90%) from drinking water with less competition of other ions present in water.
文摘This work examined the removal of Pb(II) using a chitosan derivative (SB, synthesized from benzaldehyde) assisted by a magnetic field. The adsorption capacity for Pb(II) was investigated. It was found that 1) the pH and concentration of the ion solution, as well as exposure time and strength of magnetic field, affected the degree of adsorption;and 2) studies of the adsorption isotherms and kinetics of ions onto SB revealed that SB showed enhanced adsorption capacity towards Pb(II) ions in a magnetic field compared with magnetically untreated samples. The Langmuir and Freundlich isotherm were applied to describe the experimental adsorption, and the maximum adsorption capacity of SB for Pb(II) was 2.5040 mg/g, when assisted by a magnetic field of 480 kA/m.
基金Supported by the Natural Science Foundation of Qinghai Province(Nos.2020-ZJ-940Q,2014-ZJ-937Q)the West Light Foundation of the Chinese Academy of Sciences(No.E010GC09)the Youth Innovation Promotion Association CAS(No.E010GC15)。
文摘Dissolved organic matter(DOM)plays a vital role in promoting carbon and nutrient cycling.It is a food source for organisms and controls the migration and transformation of trace metals and other contaminants in aquatic systems.The contributions of aquatic DOM to the environment and ecology of a system are closely related to its abundance and chemical structure.In this study,the chemical composition and binding properties of DOM in a hypersaline lake watershed were investigated for the fi rst time using dissolved organic carbon(DOC)analysis,absorption spectroscopy,Fourier transform infrared spectroscopy,pyrolysis-GC-MS(Py-GC-MS),and fl uorescence parallel factor(PARAFAC)analysis combined with Pb(II)titration techniques.The results showed that DOM from the tributaries that fl owed into the lake had a lower DOC content,higher molecular weight,and higher specifi c UV absorbance than the DOM in lake water.Protein-like fl uorophores were mainly found in tributary and lake surface water DOM(LSDOM)and humic-like substances were abundant in lake groundwater DOM(LGDOM).Using this multi-methodological approach,we found that the DOM from the hypersaline lake watershed was mainly from microbial origins,and consisted of aromatics,carbohydrates,and aliphatics.The results from quantitative analysis showed that DOM from the infl owing tributaries contained more aromatics,lower carbohydrates,and lower aliphatics than DOM in the lake.Monocyclic aromatic hydrocarbons and carbohydrates were more abundant in LSDOM than LGDOM.The results from the Pb(II)titration technique coupled with PARAFAC analysis suggested that PARAFAC-derived components had relatively low condition stability constants(log K_(M)<2).Of the two types of lake DOM,the LGDOM had a higher Pb(II)binding potential than the LSDOM.From this study we have improved our understanding of how DOM within a hypersaline lake watershed varies in its composition and potential to bind with metals.
文摘Chemical compositions of natural zeolites, porcelanite (opal-CT) and local sands were determined by X-ray fluorescence (XRF) and correlated with their Pb(II) removal efficiencies. Zeolites and porcelanite were from the Mikawer, Aritain and Hannon areas in Jordan. Sands (white, red and yellow) were from the United Arab Emirates (UAE). The effect of Pb(II) concentration and zeolite dosage on removal efficiency was investigated at 25.0°C using the batch equilibrium method. Commercial kaolinite, silica and alumina were also studied for comparison. Removal efficiencies, in mg Pb(II)/g adsorbent, were: 76.9, 52.7 and 42.1 for Hannon, Mikawer and Aritain zeolites, respectively;58.2 for porcelanite;29.7, 11.0 and 8.5 for yellow, red and white sand, respectively;7.2, 3.3 and 1.3 for kaolinite, silica and alumina, respectively. XRF data indicate that adsorbents with intermediate molar ratios of Si/Al, in the range 2.70 - 2.93, are most efficient in Pb(II) removal. Scanning electron microscope (SEM) images of adsorbents suggest that morphology, in addition to chemical composition, plays a key role. In particular, a combination of factors, including shapes and sizes of crystals, channels in zeolites and pores in porcelanite, appear to favor removal of Pb(II).
基金This work was supported by the National Natural Science Foundation of China(Nos.42077184,41772251 and 41521001)the National Key Research and Development Program(No.2018YFC1801700).
文摘Antimony(Sb)is a toxic and carcinogenic element that often enters soil in the form of antimony trioxide(Sb_(2)O_(3))and coexists with manganese(Mn)in weakly alkaline conditions.Mn oxides such as birnessite have been found to promote the oxidative dissolution of Sb_(2)O_(3),but few researches concerned the co-transformations of Sb_(2)O_(3) and Mn(II)in environment.This study investigated themutual effect of abiotic oxidation of Mn(II)and the coupled oxidative dissolution of Sb_(2)O_(3).The influencing factors,such as Mn(II)concentrations,pH and oxygen were also discussed.Furthermore,their co-transformed mechanism was also explored based on the analysis of Mn(II)oxidation products with or without Sb_(2)O_(3) using XRD,SEM and XPS.The results showed that the oxidative dissolution of Sb_(2)O_(3) was enhanced under higher pH and higher Mn(II)loadings.With a lower Mn(II)concentration such as 0.01 mmol/L Mn(II)at pH 9.0,the improved dissolution of Sb_(2)O_(3) was attributed to the generation of dissolved intermediate Mn(III)species with strong oxidation capacity.However,under higher Mn(II)concentrations,both amorphous Mn(III)oxides and intermediate Mn(III)species were responsible for promoting the oxidative dissolution of Sb_(2)O_(3).Most released Sb(∼72%)was immobilized by Mn oxides and Sb(V)was dominant in the adsorbed and dissolved total Sb.Meanwhile,the presence of Sb_(2)O_(3) not only inhibited the removal of Mn(II)by reducing Mn(III)to Mn(II)but also affected the final products of Mn oxides.For example,amorphous Mn oxides were formed instead of crystalline Mn(III)oxides,such as MnOOH.Furthermore,rhodochrosite(MnCO_(3))was formed with the high Mn(II)/Sb_(2)O_(3) ratio,but without being observed in the low Mn(II)/Sb_(2)O_(3) ratio.The results of study could help provide more understanding about the fate of Sb in the environment and the redox transformation of Mn.
文摘Influence of Hg(II) and Pb(II) ions on C-Phycocyanin (C-PC) from cyanobacteria Spirulina platensis was investigated using Fluorescence spectroscopy. Fluorescence measurements demonstrate quenching of C-PC emission by Hg(II) and Pb(II), and blue shifts in the fluorescence spectra. The effect of DNA on the fluorescence of Hg(II)-and Pb(II)-C-PC (from Spirulina platensis) complexes was also studied. It was shown that the fluorescence intensity of Hg-C-PC after addition of DNA gave rise to the fluorescence buildup. At the same time, addition of DNA to the Pb(II)-C-PC complexes showed no such effect. In the case of Hg(II)-C-PC, fluorescence intensity significantly decreases in time, while for Pb(II)-C-PC, decrease of the fluorescence intensity is not significant, but blue shift of the peak takes place.
文摘In this study, the modified rice bran was tested to remove Pb(II) from water. Batch experiments were carried out to evaluate the adsorption characteristics of the modified rice bran for Pb(II) removal from aqueous solutions. The adsorption isotherms, thermodynamic parameters, kinetics, pH effect, and desorbability were examined. The results show that the maximum adsorption capacity of the modified rice bran was approximately 70.8 mg Pb(II)/g absorbent at temperature of 25℃ and at the initial Pb(II) concentration of 400 mg/L and pH 7.0. And the adsorption isotherm data could be well fitted by both Langmuir equation and Freundlich equation. Thermodynamic studies confirmed that the process was spontaneous and endothermic. The adsorbed amounts of Pb(II) tend to increase with the increase of pH. The adsorption kinetic data can be satisfactorily described by either of the power functions and simple Elovich equations. The desorbability of Pb(II) is about 15-20%, and it is relatively difficult for the adsorbed Pb(II) to be desorbed. The relatively low cost and high capabilities of the rice bran make it potentially attractive adsorbent for the removal of Pb(II) from wastewater.
