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1.
Asexual spores of the filamentous fungus Rhizopus arrhizus were used as the resting biomass as they tolerate chitosan gelling for mycelia growing in chitosan beads. Biosorption of lead using the dead detergent pre-treated chitosan-immobilised and grown fungal beads was performed with initial lead (II) nitrate concentrations ranging from 9.02 to 281.65 mg/L. The adsorption data were best correlated with equilibrium adsorption isotherms in the order Redlich–Peterson, Langmuir, Freundlich and Fritz–Schlünder by non-linear regression. The biosorption kinetic model of pseudo second-order (R 2 > 0.99) fitted better than pseudo first-order and modified pseudo first-order models. Among the four pseudo second-order kinetic models, the Blanchard model was the best fit for the experimental biosorption data. The rate-limiting step of biosorption of lead was shown to be intraparticle diffusion controlled according to Weber and Morris model fitting. The beads could be regenerated using 1 M nitric acid solution. This illustrated the good performance of the beads for regenerated sorption/desorption at least five cycles.  相似文献   

2.
Landfill leachate is a high-strength wastewater. If it is not managed properly, it can pollute surrounding environment. The aim of this study is to determine the simultaneous adsorption capacity of iron oxide-coated gravel for metals such as Cd(II), Cu(II), Fe(II), Ni(II) and Zn(II) in high-strength leachate sample. Different operating conditions such as pH, time, and dosages were investigated to determine the kinetics and mechanism of adsorption process. Coating with iron oxide changed the external surface of gravel. The adsorption capacities increased with increased pH, and the optimum pH was found to be 7. High removal rates were observed in a short period of time. The Freundlich model fitted reasonably well to the experimental data, indicating multilayer adsorption process and the heterogeneity of the surface (R 2 ranging 0.57–0.94). The Temkin model fitted well to the experimental data as well (R 2 ranging 0.67–0.98), indicating that the adsorption is an exothermic process. The adsorption of ions was found to obey second-order kinetics, indicating one-step, surface-only adsorption process. The degree of metal adsorption on iron oxide-coated gravel at pH 7 was in the order Cu(II) > Cd(II) > Fe(II) > Zn(II) > Ni(II).  相似文献   

3.
As, Hg and Pb are examples of heavy metals which are present in different types of industrial effluents responsible for environmental pollution. Their removal is traditionally made by chemical precipitation, ion-exchange and so on. However, this is expensive and not completely feasible to reduce their concentrations to the levels as low as required by the environmental legislation. Biosorption is a process in which solids of natural origin are employed for binding the heavy metal. It is a promising alternative method to treat industrial effluents, mainly because of its low cost and high metal binding capacity. The kinetics was studied for biosorption experiments using coconut fiber for As (III), Hg (II) and Pb (II) ions adsorption. The specific surface area and surface charge density of the coconut fiber are 1.186×1025 (m2/g) and 5.39 ×1024 (meq/m2), respectively. The maximum adsorption capacity was found to be the highest for Pb (II) followed by Hg (II) and As (III). The modification of the adsorbent by thiolation affected the adsorption capacity. Equilibrium sorption was reached for the metal ions at about 60 min. The equilibrium constant and free energy of the adsorption at 30 °C were calculated. The mechanism of sorption was found to obey the particle-diffusion model. The kinetic studies showed that the sorption rates could be described by both pseudo first-order and pseudo second-order models. The pseudo second-order model showed a better fit with a rate constant value of 1.16 × 10?4/min. for all three metal ions. Therefore, the results of this study show that coconut fiber, both modified and unmodified, is an efficient adsorbent for the removal of toxic and valuable metals from industrial effluents.  相似文献   

4.
Adsorption of lead using a new green material obtained from Portulaca plant   总被引：2，自引：1，他引：1  
In the present study the potential of a new green material obtained from Portulaca oleracea plant was investigated. The material was used without any chemical treatment to study the adsorption behavior of lead ions from aqueous solution. Various batch experiments were carried out using different experimental conditions such as pH, contact time, adsorbent concentration, and metal ion concentration to identify the optimum conditions. The influence of these parameters on the adsorption capacity was studied. Results showed the optimum initial pH for adsorption as 6. Adsorption equilibrium was reached in 120?min. The adsorption data were modeled using both the Langmuir and Freundlich classical adsorption isotherms. Results show ~78% removal of lead from aqueous solution. The kinetic data corresponded well with pseudo second-order equation. From the initial results, the green material obtained from the waste of Portulaca seems to be a potential low-cost adsorbent for removal of lead ions from water.  相似文献   

5.
Ruppia maritima and Echinodorus amazonicus were prepared in a dehydrated powder form. The characteristics and mechanisms of adsorption of heavy metals were studied under various pH values, reaction times, and heavy metal ion concentrations. The results showed that under different pH and reaction time conditions, heavy metal adsorption was lead > cadmium > zinc > copper. The adsorption of lead increased linearly with the lead concentration. For cadmium, zinc and copper, the adsorption was saturated when metal ion concentration exceeded 200 mg/L. When a Freundlich model was applied, R 2 values for the heavy metal adsorption by the aquatic plants mostly exceeded 0.9. The adsorption of heavy metal ions by these two aquatic plant powders was better explained by the Lagergren second-order equation than the first-order equation. From the Fourier Transform Infrared spectra, there was an adsorption peak at 2,115 cm?1 for R. maritima. The peak shape did not change with metal affiliation except there was a shift of peak wavelength before adsorption. The results indicate that the mechanism of heavy metal adsorption by the two species is not simply on the mono-molecular layer level, and that intra-particulate dispersal is the dominant process. Heavy metal pollution does not affect the basic chemical components, and major substances involved in heavy metal adsorption including carbohydrates, cell wall pectin, and protein functional groups.  相似文献   

6.
Beidellite, a low-cost, locally available and natural mineral was used as an adsorbent for the removal of lead and cadmium ions from aqueous solutions in batch experiments. The kinetics of adsorption process was tested for the pseudo first-order, pseudo second-order reaction and intra-particle diffusion models. The rate constants of adsorption for all these kinetic models were calculated. Comparison amongst the models showed that the sorption kinetics was best described by the pseudo second-order model. Langmuir and Freundlich isotherm models were applied to the experimental equilibrium data for different temperatures. The adsorption capacities (Q°) of beidellite for lead and cadmium ions were calculated from the Langmuir isotherm. It was found that adsorption capacity was in the range of 83.3–86.9 for lead and 42–45.6 mg/g for cadmium at different temperatures. Thermodynamic studies showed that the metal uptake reaction by beidellite was endothermic in nature. Binary metal adsorption studies were also conducted to investigate the interactions and competitive effects in binary adsorption process. Based on the optimum parameters found, beidellite can be used as adsorbent for metal removal processes.  相似文献   

7.
Effects of initial concentrations of Moringa oleifera seed coagulant for removing Chemical Oxygen Demand and Total Dissolved Solids from municipal solid waste leachate have been evaluated at an optimum pH of 7 and temperature of 318 K. The kinetic data obtained from the experiments were fitted to the pseudo first-order, pseudo second-order, Elovich and intraparticle diffusion models. Based on a regression coefficient (R 2), the equilibrium (kinetic) data were best fitted with the Elovich model (R 2 = 0.993 for Chemical Oxygen Demand and R 2 = 0.996 for Total Dissolved Solids) than that of other models. The results of the kinetic models study indicated that the adsorption capacity of M. oleifera seed as a coagulant for removing Chemical Oxygen Demand and Total Dissolved Solids in a leachate increased up to 100 mg L?1, beyond which the adsorption capacity got reduced. Finally, the present study concluded that M. oleifera seed coagulant could be employed effectively for the removal of Chemical Oxygen Demand and Total Dissolved Solids in a municipal solid waste leachate.  相似文献   

8.
Acacia nilotica was used for the adsorption of Reactive Black 5 (RB5) dye from an aqueous solution. Both the raw and activated (with H3PO4) carbon forms of Acacia nilotica (RAN and ANAC, respectively) were used for comparison. Various parameters (including dye concentration, contact time, temperature, and pH) were optimized to obtain the maximum adsorption capacity. RAN and ANAC were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The maximum experimental adsorption capacities for RAN and ANAC were 34.79 and 41.01 mg g?1, respectively, which agreed with the maximum adsorption capacities predicted by the Langmuir, Freundlich, and Dubinin–Radushkevich equilibrium isotherm models. The adsorption data of ANAC showed a good fit to the isotherm models based on the coefficient of determination (R 2): Langmuir type II (R 2 = 0.99) > Freundlich (R 2 = 0.9853) > Dubinin–Radushkevich (R 2 = 0.9659). This result suggested monolayer adsorption of RB5 dye. The adsorption of RB5 dye followed pseudo-second-order kinetics. The RAN adsorbent reflected an exothermic reaction (enthalpy change, ΔH = ?0.006 kJ mol?1) and increased randomness (standard entropy change, ΔS = 0.038 kJ mol?1) at the solid–solution interface. In contrast, ANAC reflected both exothermic [?0.011 kJ mol?1 (303–313 K)] and endothermic [0.003 kJ mol?1 (313–323 K)] reactions. However, the ΔS value of ANAC was lower when the RB5 adsorption increased from 313 to 323 K. The negative values for the Gibbs free energy change at all temperatures indicated that the adsorption of RB5 dye onto RAN and ANAC was spontaneous in the forward direction.  相似文献   

9.
Peganum harmala seeds were assessed as biosorbent for removing Pb2+, Zn2+and Cd2+ ions from aqueous solutions. The effects of various parameters such as the aqueous solution pH, the contact time, the initial metal concentration and the amount of adsorbent in the process were investigated. The adsorption efficiencies increased with pH. It was found that about 95 % of lead, 75 % of zinc and 90 % of cadmium ions could be removed from 45 ml of aqueous solution containing 20 mg l?1 of each cation with 2 g of adsorbent at pH 4.5 after 15 min. The quantitative desorption of cadmium from adsorbent surface was achieved using 10 ml of a 0.5 M nitric acid solution. This condition was attained for lead and zinc ions with 10 ml of 1 M hydrochloric acid solution. Kinetic investigation of the process was performed by considering a pseudo-second-order model. This model predicts the chemisorption mechanism of the process. Langmuir, Freundlich, Temkin and Dubinin–Radushkevich models were tested for describing the equilibrium data. It was found that the Freundlich model describes the experimental data resulting from the adsorption of lead ions. However for cadmium and zinc ions, the adsorption equilibria were interpreted with the Langmuir model.  相似文献   

10.
The present article explores the ability of five different combinations of two adsorbents (Arachis hypogea shell powder and Eucalyptus cameldulensis saw dust) to remove Pb(II) from synthetic and lead acid batteries wastewater through batch and column mode. The effects of solution pH, adsorbent dose, initial Pb(II) concentration and contact time were investigated with synthetic solutions in batch mode. The Fourier transform infrared spectroscopy study revealed that carboxyl and hydroxyl functional groups were mostly responsible for the removal of Pb(II) ions from test solutions. The kinetic data were found to follow pseudo-second-order model with correlation coefficient of 0.99. Among Freundlich and Langmuir adsorption models, the Langmuir model provided the best fit to the equilibrium data with maximum adsorption capacity of 270.2 mg g?1. Column studies were carried out using lead battery wastewater at different flow rates and bed depths. Two kinetic models, viz. Thomas and Bed depth service time model, were applied to predict the breakthrough curves and breakthrough service time. The Pb(II) uptake capacity (q e = 540.41 mg g?1) was obtained using bed depth of 35 cm and a flow rate of 1.0 mL min?1 at 6.0 pH. The results from this study showed that adsorption capacity of agricultural residues in different combinations is much better than reported by other authors, authenticating that the prepared biosorbents have potential in remediation of Pb-contaminated waters.  相似文献   

11.
Activated carbon produced from fluted pumpkin (Telfairia occidentalis) seed shell was utilized for the removal of lead (II) ion from simulated wastewater. Adsorption tests were carried out in series of batch adsorption experiments. Several kinetic models (Bhattacharya-Venkobacher, Elovich, pseudo first and second order, intra-particle and film diffusion) were tasted for conformity to the experimental data obtained. The Langmuir and Freundlich adsorption models were also used to test the data. The amount of lead (II) ion adsorbed at equilibrium from a 200 mg/L solute concentration was 14.286 mg/g. The experimental data conform very well to the pseudo-second order equation where equilibrium adsorption capacities increased with increasing initial lead (II) concentration. The rate of the adsorption process was controlled by the film (boundary layer) diffusion as the film diffusion co-efficient values obtained from data analysis were of the order of 10 6cm2/s. From the plots, the linear regression coefficient (R2) of the Langmuir model was higher than that of the Freundlich: the adsorption isotherm obeyed the Langmuir model better than the Freundlich model.  相似文献   

12.
Mine residue and leachate were sampled from an acid mine drainage site near Arroyo San Pedro, which is one of the oldest abandoned mine districts in San Luis Potosi, Mexico, and characterized by X-ray diffraction and inductively coupled plasma-optical emission spectroscopy, confirming the presence of Fe, As, and SO4 2?. To address this problem, chitosan network (net-CS) and chitosan network-N-vinylcaprolactam/N–N-dimethylacrylamide (net-CS)-g-NVCL/DMAAm hydrogels were synthesized and used as adsorbents of the different ions present in the aforementioned leachate by batch equilibrium procedure. Kinetics, isotherms, and ions dissolved in leachate were evaluated. The gels showed the highest adsorption capacity for As and Fe ions. The adsorption capacity of the net-CS hydrogels for As (V) and Fe(III) was 0.786 and 76.85 mg/g, respectively, attained after 50 h. The surface of the hydrogels was investigated by scanning electron microscopy and Fourier transform infrared spectroscopy, before and after the adsorption process, where the presence of a bond between the hydrogels and heavy metals ions, which is commonly observed in organic groups, was observed. In addition, Freundlich and Langmuir adsorption isotherms constants were determined for the As and Fe ions, and it was found that the Freundlich isotherm, with a first-order pseudo model, better fitted the adsorption process, indicating heterogeneous sorption, and the retention process occurred by chemisorption. The results from the Geochemist´s Workbench (GWB) software program revealed that arsenates, such as H3AsO4, H2AsO4 ?, as well as Fe++, FeSO4(aq) and FeOH+ were the common aqueous species found in the leachate at pH = 2.9.  相似文献   

13.
Homogenized samples of raw clays resulting from two (2) different lots of natural clays from Maghnia (Algeria) have been assessed for their potential use in the removal of Pb2+ and Zn2+ ions from industrial liquid wastes (LW). Raw and acid-activated samples have been characterized by powder X-ray diffraction, FT-IR spectroscopy, electron microscopy (SEM), and X-ray fluorescence (XRF) and used as adsorbents for the removal of Pb2+ and Zn2+ ions from aqueous system using adsorption method under different conditions. The effect of factors including contact time, pH, and dosage on the adsorption properties of Pb2+ and Zn2+ ions onto clays was investigated at 25 °C. The obtained results revealed that the removal percentages of Pb2+ and Zn2+ ions, from both aqueous solution (AS) and LW, were varying between 90 and 98% for 40 min and optimal pH values ranged from 5 to 6 for Pb2+ and Zn2+ ions, respectively. The kinetics of both Pb2+ and Zn2+ ion adsorption fitted well with the pseudo-second-order model. Langmuir, Freundlich, and Temkin adsorption isotherms were used, and their constants were evaluated. The values of thermodynamic parameters, ΔH°, ΔS°, and ΔG° indicated that the adsorption of Pb2+ and Zn2+ ions was spontaneous and exothermic process in nature. The adsorption and desorption isotherms indicated that Pb2+ and Zn2+ adsorption to raw clays was reversible. The experimental results obtained showed that the raw clays from Maghnia (Algeria) had a great potential for removing Pb2+ and Zn2+ ions from industrial liquid wastes using adsorption method.  相似文献   

14.
In this work, the effectiveness of native and chemically modified rice bran to remove heavy metal Pb(II) ions from aqueous solution was examined. Chemical modifications with some simple and low-cost chemicals resulted in enhancement of the adsorption capacities and had faster kinetics than native rice bran. Experiments were conducted in shake flasks to monitor the upshot of parameters over a range of pH, initial Pb(II) concentrations and contact times using a batch model study. The sorption capacities q (mg g?1) increased in the following order: NaOH (147.78), Ca(OH)2 (139.08), Al(OH)3 (127.24), esterification (124.28), NaHCO3 (118.08), methylation (118.88), Na2CO3 (117.12) and native (80.24). The utmost uptake capacity q (mg g?1) was shown by NaOH-pretreated rice bran. The results showed that, using NaOH-modified rice bran, the chief removal of Pb(II) was 74.54 % at pH 5, primary Pb(II) concentration 100 mg L?1 and contact time 240 min. Equilibrium isotherms for the Pb(II) adsorption were analyzed by Langmuir and Freundlich isotherm models. The Langmuir isotherm model, showing Pb(II) sorption as accessible through the high value of the correlation coefficient (R 2 = 0.993), showed a q max value of 416.61 mg g?1. The kinetic model illustrated adsorption rates well, depicted by a second order, which gives an indication concerning the rate-limiting step. Thermodynamic evaluation of the metal ion ?G o was carried out and led to the observation that the adsorption reaction is spontaneous and endothermic in nature. NaOH chemically modified rice bran was a superb biosorbent for exclusion of Pb(II) and proved to be excellent for industrial applications.  相似文献   

15.
The ability of ochre to remove Pb(II) and Cu(II) from aqueous media has been studied by batch sorption studies varying the contact time, initial metal concentration, initial solution pH and temperature to understand the adsorption behaviour of these metals through adsorption kinetics and isotherms. The pH of the solution and the temperature controlled the adsorption of metal ions by ochre and rapid uptake occurred in the first 30 min of reaction. The kinetics of adsorption followed a pseudo-second-order rate equation (R 2 > 0.99) and the isotherms are well described by the Freundlich model. Adsorption of metals onto ochre is endothermic in nature. Between the two metals, Pb(II) showed more preference towards the exchangeable sites on ochre than Cu(II). This study indicates that ochre is a very effective adsorbent in removing Pb(II) and Cu(II) from the aqueous environment with an adsorptive capacity of 0.996 and 0.628 mg g?1 and removal efficiency of 99.68 and 62.80 %, respectively.  相似文献   

16.
In this study, the feasibility of using a low-cost adsorbent mixture composed of leonardite (L) and clinoptilolite (C) was evaluated by batch adsorption method using different parameters such as mixing ratio, contact time, pH, temperature, and adsorbent amount for the removal of Zn (II) ions from an aqueous solution. The adsorbents were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and Raman spectroscopy. Additionally, leonardite–clinoptilolite mixture was analyzed by scanning electron microscopy coupled with energy dispersive X-ray. The Zn (II) adsorption along with an unprecedented adsorption capacity of 454.55 mg g?1 for unmodified natural sorbents was obtained by mixing leonardite and clinoptilolite (LC) without any pretreatment at a ratio of 3:1, using 0.1 g of sorbent at a pH 6, for 2 h of contact time. The experimental data showed a good fit for the Langmuir isotherm model. The thermodynamic parameters revealed that the present adsorption process was spontaneous and exothermic in nature (25–50 °C). The kinetic results of the adsorption showed that the Zn (II) adsorption onto the LC follows pseudo-second-order model. The resultant LC mixture has an excellent adsorption capacity of a Zn (II) aqueous solution, and data obtained may form the basis for utilization of LC as an unpretreated low-cost adsorbent for treatment of metalliferous industrial wastewater.  相似文献   

17.
This study analyses the adsorption of Pb(II) and Cr(III) in soils. These metals are commonly found together in nature in urban wastes or industrial spillages, and the theoretical approach of the work was to evaluate the response of the soil to continuous Cr and Pb spillages to soil in terms of several physicochemical parameters. The influence of an anthropogenic input of phosphorus was evaluated. Continuous flow experiments were run in duplicates in acrylic columns (25 cm × 3.2 cm). The influent Cr(III) and Pb(II) solutions of 10 mg l?1 and 25 mg l?1 at pH 5 were pumped upward through the bottom of the columns to ensure saturation flow conditions. Also, successive experiments were run with the above concentrations of Cr(III) and Pb(II) and NaH2PO4, keeping metal to phosphorus ratio of 1:0, 1:0.1 and 1:1. Modelling parameters included Freundlich and Langmuir equations, together with the Two-site adsorption model using CXTFIT code. Results obtained allowed concluding that Pb(II) adsorption presents a certain degree of irreversibility and the continued spillages over soil increment the fraction which is not easily desorbed. Cr(III) desorption was almost complete, evidencing its high mobility in nature. The presence of an anthropogenic input of phosphorus leads to a marked increase of both Pb(II) and Cr(III) adsorption in soils. Z-potential measurements allow to discard the electrostatic attraction of Cr(III) and Pb(II) with the surface charged soil as the dominant process of metal sorption. Instead, CheaqsPro simulation allows to identify PbH2PO4 +, PbHPO4 (aq) and CrHPO4 + as the dominant species which regulate Cr(III) and Pb(II) transport in soils.  相似文献   

18.
The adsorption of cadmium from simulated mining wastewater by coal waste (CW) and calcination-modified coal waste (MCW) was investigated. Effects of pH, initial concentration, particle size of adsorbent, adsorbent dosage and temperature were studied in batch experiments. The adsorption efficiency for cadmium increased with increasing pH, and the optimum pH for cadmium adsorption onto MCW and CW was 6.0 and 6.5, respectively. Kinetic experiments showed that the adsorption equilibrium was reached within 120 min and followed pseudo-second-order model well. The adsorption isotherm data fit Langmuir and Freundlich models, and the adsorption capacity of cadmium on the two adsorbents increased with increasing temperature from 298 to 318 K. MCW had a higher adsorption capacity of cadmium than CW, because calcination treatment can make CW to have more loose structure and higher specific surface area. Thermodynamic parameters, the Gibbs free energy change (?G0), enthalpy change (?H0) and entropy change (?S0), were calculated and the results showed that the adsorption of cadmium on CW and MCW was spontaneous and endothermic. Fourier transform infrared studies indicated silanol and aluminol groups were responsible for cadmium binding. The desorption results indicated that the two adsorbents could be used repeatedly at least three times without significant decrease in the adsorption capacity for cadmium. The results suggested that modified CW could have high potential as low-cost adsorbent for cadmium removal.  相似文献   

19.
A novel polyurethane foam/organobentonite/iron oxide nanocomposite adsorbent was successfully prepared via in situ polymerization of toluene diisocyanate and polyol in presence of 5 wt% organobentonite/iron oxide. The obtained nanocomposite was characterized in detail, and the results revealed that the clay layers are exfoliated and/or intercalated in the polymer matrix forming a nanocomposite structure. The application of the prepared nanocomposite for adsorption of cadmium ions from aqueous solution was tested as a function of various experimental parameters using batch procedures. Adsorptive removal of Cd(II) onto the nanocomposite attained maximum at adsorbent content 1.5 g/L, pH 6, and the equilibrium was established within 60 min. Kinetic studies showed that the experimental data fit very well to pseudo-second-order model, and the adsorption process proceeds through three steps. It was found that external liquid film and intraparticle diffusion steps deeply affect the rate of Cd2+ ions adsorption onto the synthesized nanocomposite. Langmuir isotherm model fitted the adsorption data better than Freundlich with a maximum adsorption capacity (q m) for Cd(II) equal to 78 mg/g under the specified experimental conditions. The synthesized nanocomposite afforded effective extraction for Cd2+ ions from natural water samples and excellent reusability feature. This study declares the potential efficiency of a new clay/polymer nanocomposite as alternative for wastewater remediation.  相似文献   

20.
In this study, the adsorption behavior of Ni(II) in an aqueous solution system using natural adsorbent Peganum harmala-L was measured via batch mode. The prepared sorbent was characterized by scanning electron microscope, Fourier transform infrared spectroscopy, N2 adsorption–desorption and pHzpc. Adsorption experiments were carried out by varying several conditions such as contact time, metal ion concentration and pH to assess kinetic and equilibrium parameters. The equilibrium data were analyzed based on the Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherms. Kinetic data were analyzed using the pseudo-first-order, pseudo-second-order and intra-particular diffusion models. Experimental data showed that at contact time 60 min, metal ion concentration 50 mg/L and pH 6, a maximum amount of Ni(II) ions can be removed. The experimental data were best described by the Langmuir isotherm model as is evident from the high R 2 value of 0.988. The adsorption capacity (q m) obtained was 68.02 mg/g at an initial pH of 6 and a temperature of 25 °C. Kinetic studies of the adsorption showed that equilibrium was reached within 60 min of contact and the adsorption process followed the pseudo-first-order model. The obtained results show that P. harmala-L can be used as an effective and a natural low-cost adsorbent for the removal of Ni(II) from aqueous solutions.  相似文献   

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