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Utilization of Erythrina variegata orientalis leaf powder for the removal of cadmium
Abstract
Removal of cadmium, a priority pollutant, is carried out by abundantly and freely available Erythrina variegata orientalis (Indian coral tree) leaf powder. The extent of removal depends on initial concentration of cadmium in the solution, pH of the solution, temperature, etc. A significant increase in percentage removal of cadmium is observed as pH is increased from 2 to 4. The percentage removal of cadmium increases marginally for pH of 4 to 7. As the initial concentration of cadmium is increased from 23 to 188 mg/L, the % removal is decreased from 98.8 to 86.1%. Freundlich and Langmuir isotherm models well describe the data indicating favourable biosorption. The biosorption is endothermic, irreversible and follows pseudo-second-order kinetics, and rate constant is 0.23 g/(mg-min) for a dosage of 40 g/L. The equilibrium agitation time is 50 min.
... Cadmium also causes Itaiitai disease. Cadmium poses serious health threats even at very low concentrations (Ajay Kumar et al., 2009). As studied by (Friberg et al.,1986) in natural unpolluted water the cadmium concentration is below 0.001mg/L. ...
... From Fig. 6, it was evaluated that the removal efficiency decreased from 92.6% to 91% as the initial metal ion concentration increased from 5 to 30 mg/L. The maximum removal was at 15 mg/L and hence 15 mg/L was considered as optimum metal ion concentration for equilibrium and kinetic studies The reason for the decrease in removal percentage as metal ion concentration increases is the accumulation of adsorbent particles at higher metal ion concentration (Ajay Kumar et al., 2009). The binding sites get occupied at lower metal ion concentrations. ...
... Hence, In the present work experiment was conducted at below pH 6. As studied by various researchers, pH value of 5 is considered good for equilibrium and Kinetics studies (AjayKumar et al., 2009). According toSalim et al. (2008) cadmium removal by combination of leaves was maximum at pH 5.Panda et al. (2006) studied the husk of Lathyrus sativus and ...
Globally, the discharge of heavy metals into the water bodies is a matter of serious concern. Heavy metals like cadmium are considered as toxic even at very low concentration. Several conventional methods are available to remove heavy metals from the wastewater. They bear high costs, generate high sludge, and consume high energy. Biosorbents provides many beneficial properties due to their good adsorption capacity for heavy metals. The present work focuses on the potential of waste leaves of Averrhoa carambola (WACLP) as an adsorbent for its ability to remove Cd (II) ions from synthetic water by batch experimental process. The adsorbent was characterized by using elemental analysis, Energy Dispersive X-ray or EDAX and Scanning Electron Micrograph (SEM). The batch experiment was carried out considering various parameters such as pH, initial metal ion concentration, contact time and dose of the adsorbent. The fitting of the experimental data was done by Langmuir, Freundlich and Temkin isothermal models. The study on isothermal models revealed that the experimental parameters were best fitted to the Langmuir isothermal model with R2 value of 0. 976.The Kinetic studies showed pseudo second order depicting chemisorption. The results showed that Averrhoa carambola is a good adsorbent for cadmium and hence it can widen the scope and prospects for future studies on heavy metal removal from the aqueous solution.
... Adsorption also plays an important role in the removal of metals from the effluents. Present work is extension study of the different parameters with different values [5]. ...
5 www.ijeas.org Abstract-An unauthorized activity of releasing harmful contaminants arising from domestic, municipal and industrial establishments into the environment is continuing unabated due to expensive treatment process and ineffective implementation of environmental legislation. In developing countries with the result there is a study increase in concentrations of pollutants sometimes reaching alarming levels and causing serious human health hazards of the life, sustaining water resource due to release of industrial effluents is one of the serious environmental problems encounter today. In the present work an attempt is made to study to effect of parameters like p H , temperature, time of contact, bisorbent dosage, size of bisorbent etc. on removal of Cadmium and determination of equilibrium, kinetics and thermodynamic parameters in a batch biosorption of cadmium by the leaf powder of Erythria Variegate Orientalies as biosorbent.
... The Fourier Transform -Infrared spectra [18] of raw LRHC and metal ion loaded LRHC are given in Fig.13 and Fig.14. The scanning electron microscope (SEM) images [19] of the raw activated carbon taken at magnitude 1000x were given in Fig.15. ...
Removal of potassium is carried out by lime loaded rice husk carbon (LRHC). The extent of removal depends on initial concentration of potassium in solution, pH of the solution, carbon dosage, temperature etc. As the concentration of potassium is increased, the removal of potassium is decreased. When the adsorbent dosage is increased from 1 g to 4 g, the removal of potassium from the salt solution is increased. As the pH increased from 3 to 6, the removal of potassium had been decreased. The amount of potassium removed increases from pH 6 to 7. Freundlich and Langmuir adsorption isotherm models indicate the occurrence of adsorption. Thermodynamic parameters show the biosorption is endothermic and non-spontaneous. Kinetics shows the adsorption is first order reaction. IR spectrum indicates the adsorption is physisorption. SEM and EDX studies show the adsorption of potassium on the carbon.
... The kinetic data for pseudo second order are furnished in Table 7. The rate of the pseudo second order equation may be dependent on the amount of solute sorbed on the surface of the adsorbent at any time and the amount sorbed at equilibrium [29]. The data of pseudo second order kinetic constants along with R 2 values are furnished in Table 7. ...
The chemically activated carbon prepared from Syzygium jambolanum nut, an agricultural waste, after activation with ammonium persulphate in the presence of sulphuric acid and then subjected to thermal activation by dolomite process, was successfully used to remove chromium (VI) from wastewater in batch studies by adsorption process. Effects of pH, carbon dose and equilibration time were determined. Desorption of Cr (VI) was done with 1M NaOH and 10% H2O2 mixture followed by 2 M HCl. Adsorption followed Freundlich, Langmuir and Temkin isotherms but was conformed to Freundlich adsorption isotherm predominantly. Kinetic studies indicated that the removal process followed pseudo second order predominantly rather than pseudo first order and reversible first order reaction. Removal of Cr (VI) followed the film diffusion process. Negative ΔG0 values indicated the feasibility and the spontaneous nature of the adsorption process. The performance of Chemically Activated High Temperature Syzygium jambolanum nut Carbon (CHSJC) was compared with a Commercial Activated Carbon (CAC).
... The percentage removal is increased with an increase in the adsorbent dosage from 10 to 50g/L. Percentage removal is increased significantly with increase in pH from 2 to 4. The percentage removal decreases as pH is increased beyond 7. [31] Zinc removal Pollution is the addition of unwanted and undesirable foreign matter to environment as a result of enormous industrial development and modernization. The discharge of untreated solid, liquid, and gaseous wastes that contaminate the physiological and ecological environment is the greatest threat to mankind. ...
This review gives an account of the current knowledge on the morphology, phytochemistry, and pharmacological aspects of Erythrina variegata. E. variegata also called Erythrina indica is a thorny deciduous tree growing to 60 feet tall. A wide range of chemical compounds have been isolated, mainly alkaloids, flavonoids, triterpenoids, and lectin. Different parts of the plant have been used in traditional medicine as nervine sedative, collyrium in opthalmia, antiasthmatic, antiepileptic, antiseptic, and as an astringent. The alkaloids extracted from the leaves of E. variegata are reported to have anti-inflammatory and analgesic activity. Isoflavonoids isolated from E. variegata having antibacterial and anthelmintic activity. E. variegata shows several other characteristic pharmacological effects like neuromuscular blocking, smooth muscle relaxant, CNS depressant, and hydrocholeretic, which are consistent with the reported uses of the plant extracts in the indigenous system of medicine. Hence the present article includes the detailed exploration of morphology, phytochemistry, and pharmacological aspects of E. variegata in an attempt to provide a direction for further research.
Adsorption of Cr(III) from aqueous system is carried out by lime loaded rice husk carbon (LRHC). BET adsorption and BJH desorption analysis of LRHC show the pores are predominantly mesopores. The adsorption of Cr(III) depends on initial concentration of adsorbate, pH of the solution, carbon dosage, agitation time and temperature. As the concentration of Cr(III) is increased, adsorption capacity of LRHC is also increased. When the adsorbent dosage is increased from 1 g to 5 g, adsorption capacity is decreased. The adsorption capacity increases from pH 1 to 3. As the pH increased from 3 to 10, the adsorption capacity had been decreased. Freundlich, Langmuir, Temkin and Dubinin Radushkevich adsorption isotherm models indicate the occurrence of adsorption. Thermodynamic parameters show the bio-sorption is exothermic, spontaneous and reversible. The adsorption is more when the agitation time is 120 min. Kinetics shows the adsorption is pseudo second order reaction. Intra-particle diffusion illustrates the adsorption is both diffusion controlled and surface controlled process. IR spectrum indicates the adsorption is physisorption. SEM analysis of LRHC and metal adsorbed LRHC show the presence of Cr(III). EDX analysis of metal adsorbed LRHC indicate the adsorption of Cr(III).
The biosorption of chromium from an aqueous solution onto Erythrina Variegata Orientalis leaf powder was investigated in batch operations. The equilibrium agitation time was 180 min. The extent of chromium biosorption
increased from 74.2% to 86.4% with decrease in biosorbent size from 150 to 45 μm for a dosage of 30 g/L. The biosorption decreased
from 99.1 (0.45 mg/g) to 45.5% (1.64 mg/g) with an increase in chromium initial concentration (C
o
) from 22.5 to 180 mg/L. The extent of biosorption was maximum at pH=3. The experimental data were well explained by Langmuir
and Redlich-Peterson isotherm models. The biosorption data followed second-order kinetics with a rate constant of 0.078 g/mg-min
for 50 g/L of 45 μm size biosorbent. The biosorption was exothermic and feasible. The biosorption was tending towards irreversibility
with increasing temperature.
Key wordsChromium–Biosorption–
Erythrina
–Thermodynamics
The fruit of the jack (Artocarpus heterophyllus) is one of the popular fruits in India, where the total area under this fruit is about 13,460 ha. A significant amount of peel (approximately 2,714-11,800 kg per tree per year) is discarded as agricultural waste, as apart from its use as a table fruit, it is popular in many culinary preparations. Treatment of jackfruit peel with sulphuric acid produced a carbonaceous product which was used to study its efficiency as an adsorbent for the removal of Cd(II) from aqueous solution. Batch experiments were performed as a function of process parameters; agitation time, initial metal concentration, adsorbent concentration and pH. Kinetic analyses made with Lagergren pseudo-first-order, Ritchie second-order and modified Ritchie second-order models showed better fits with modified Ritchie second-order model. The Langmuir-Freundlich (Sips equation) model best defined the experimental equilibrium data among the three isotherm models (Freundlich, Langmuir and Langmuir-Freundlich) tested. Taking a particular metal concentration, the optimum dose and pH required for the maximum metal removal was established. A complete recovery of the adsorbed metal ions from the spent adsorbent was achieved by using 0.01 M HCl.
The present study involves an investigation of a low-cost adsorbent, vermiculite for the removal of cadmium from aqueous solutions. The effects of pH and contact time on the adsorption process were examined. The optimum pH for adsorption was found to be 6. Residual cadmium concentration reached equilibrium in four hours and the rate of cadmium adsorption by vermiculite was rapid in the first hour of the reaction time. Ho's pseudo second order model best described the reaction rate. Batch adsorption experiments conducted at room temperature (22±1°C) showed that the adsorption pattern followed the Freundlich isotherm model. The maximum removal of cadmium obtained from batch studies was 96%. Thomas model was used to describe the adsorption data from column studies. Overall, the results showed that vermiculite could be considered as a potential adsorbent for cadmium removal from aqueous solutions.
Crosslinked cationic starch maleates (CCSM) containing quaternary ammonium cationic groups were prepared by a dry reaction. The adsorption behavior of crosslinked cationic starch maleates for Cr(VI) was investigated. Physicochemical factors such as equilibrium time, temperature, and initial solution pH affecting magnitude of Cr(VI) adsorption were studied. Their adsorption behavior was found to follow langmuir isotherm. The adsorption capacity decreased with increasing DS of anionic maleic groups. The thermodynamic investigation demonstrated that the adsorption process was exothermic, and thermodynamic parameters were calculated at different DS.
Equilibrium isotherms have been studied for the adsorption of four dyestuffs, namely, Acid Blue 25, Acid Blue 158, Mordant Yellow 5, and Direct Red 84, onto chitin. Langmuir and Freundlich constants have been determined and the effects of chitin particle size and solution temperature have been investigated. Theoretical isotherms have been compared with experimental data and good agreement was obtained using a composite isotherm of the general form: Ye = iCe/(1 + jCem), where i,j, and m are constants.
The aim of this work is the investigation of possible use of flyash in the removal of zinc (Zn2+) and cadmium (Cd2+) contained in aqueous solutions. Batch adsorption experiments wereperformed in order to evaluate the removal efficiency oflignite-based fly ash. The parameters studied include contact time, pH,temperature, initial concentration of the adsorbate and fly ashdosage. The contact time necessary to attain equilibrium was found to be two hours. Maximum adsorption occurred in the pH range of 7.0 to 7.5. The percent adsorption of Zn2+ and Cd2+ increased with an increase in concentration of Zn2+ and Cd2+, dosage of fly ash and temperature. Theapplicability of Langmuir isotherm suggests the formation ofmonolayer coverage Zn2+ and Cd2+ ions at the outer surface of the adsorbent. Thermodynamic parameters suggested the endothermic nature of the adsorption process. The fly ashwas found to be an metal adsorbent as effective as activated carbon.
The effects of the pH, agitation speed, particle size, and concentration of corncob particle on the adsorption kinetics of cupric and cadmium ions were investigated in this study. It was found that the uptakes of cupric and cadmium ions on corncob particles increased with increasing the initial pH and agitation speed, and with decreasing the particle size. The amount of adsorbed ions also increased with increasing the concentration of corncob particles, but the amount of the adsorbed ions/unit mass of adsorbent diminished. Based on the elimination of the external and intraparticle diffusions, the intrinsic forward and backward rate constants in a reversible surface reaction model combined with an effectiveness factor were estimated for cadmium ions to be 2.88/(mmol min) and 0.184/min. The maximum adsorption capacity and the effectiveness factor in this model were determined for copper and cadmium ions as a function of the initial pH and particle size. Both values increased with increasing the initial pH, and decreasing the size and concentration of corncob particle. The simple external diffusion model can describe only the solute change in solution for initial 5 min, which suggested that adsorption of cadmium on corncob particles was controlled first by the external diffusion, and then by the intraparticle diffusion. The external mass transfer coefficients first increased with increasing the modified Reynolds number, and then reached a maximum value.
The ability of dealginated seaweed waste, a waste material derived from the commercial processing of seaweed for alginate production, to remove cadmium from solution was determined. Cadmium sorption was found to be rapid (91% removal within 5 min), achieving a residual concentration of 0.8 mg L-1 after 1-h contact time from an initial solution concentration of 10 mg L-1. The binding of cadmium by dealginate was found to be pH dependent, optimal sorption occurring at around pH 6-8. The mechanism of cadmium ion binding by dealginate was investigated by a number of techniques. Potentiometric titration of the dealginate revealed two distinct pKa values, the first having a value similar to carboxyl groups and the second comparable with that of saturated thiols and amines. Esterification of the dealginate resulted in the subsequent reduction in cadmium sorption (95% to 17%), indicating that carboxyl groups are largely responsible for sorption. Evidence from FT-IR spectra confirmed the presence of carboxyl groups in untreated dealginate, while the number of carboxyl groups was markedly reduced in the esterified sample. Furthermore, the FT-IR spectrum for dealginate was found to be similar to that previously reported for mannuronic acid-rich calcium alginate. Determination of a molar ratio in the displacement of calcium by cadmium on dealginate further supported the presence of an ion-exchange relationship. The ion-exchange constant was calculated to be 0.329 x 10(-6). The speciation of cadmium in solution both before and after sorption was determined by an ion-selective electrode (ISE) technique. The findings of this study suggest that the sorption of cadmium by dealginate is mainly due to an ion-exchange mechanism.
Adsorption behaviour of Ni(II), Zn(II), Cd(II) and Cr(VI) on untreated and phosphate-treated rice husk (PRH) showed that adsorption of Ni(II) and Cd(II) was greater when PRH was used as an adsorbent. Sorption of Cd(II) was dependent on contact time, concentration, temperature, adsorbent doses and pH of the solution. The Langmuir constants and thermodynamic parameters have been calculated at different temperatures. It was found that recovery of Cd(II) from synthetic wastewater by column operation was better than a batch process.
Juniper is a small-diameter underutilized lignocellulosic material. We evaluated the efficacy of base-treated juniper fiber (BTJF) for cadmium (Cd2+) sorption and the viability of juniper fiber as a sorbent for removing Cd2+ from water. Fourier transform infrared spectroscopy analysis indicated that carboxylate ion is a major functional group responsible for Cd2+ sorption. The apparent ideal sodium hydroxide concentration for base treatment is approximately 0.5M. A batch sorption isotherm test showed that equilibrium sorption data were better represented by the Langmuir model than the Freundlich model. After base treatment, the maximum Cd2+ sorption loading, Qmax, was greatly improved (9.18-29.54 mg/g), despite a decrease in specific surface area. A pseudo-second-order kinetic model fitted well for the sorption of Cd2+ onto BTJF. Initial metal ion concentration and treatment alkalinity were found to be major parameters influencing the kinetics of the sorption reaction. As a result of its strong ability to bind cadmium and its faster kinetics in low concentration, BTJF could be an inexpensive and efficient sorbent for removing heavy metals from stormwater runoff.
A novel biosorbent rice polish has been successfully utilized for the removal of cadmium(II) from wastewater. The maximum removal of cadmium(II) was found to be 9.72 mg g(-1) at pH 8.6, initial Cd(II) concentration of 125 mg l(-1) and temperature of 20 degrees C. The effect of different parameters such as contact time, adsorbate concentration, pH of the medium and temperature were investigated. Dynamics of the sorption process were studied and the values of rate constant of adsorption, rate constant of intraparticle diffusion and mass transfer coefficient were calculated. Different thermodynamic parameters, viz., changes in standard free energy, enthalpy and entropy have also been evaluated and it has been found that the reaction was spontaneous and exothermic in nature. The applicability of Langmuir isotherm showed monolayer coverage of the adsorbate on the surface of adsorbents. A generalised empirical model was proposed for the kinetics at different initial concentrations. The data were subjected to multiple regression analysis and a model was developed to predict the removal of Cd(II) from wastewater.
Apricot stones were carbonised and activated after treatment with sulphuric acid (1:1) at 200 degrees C for 24 h. The ability of the activated carbon to remove Ni(II), Co(II), Cd(II), Cu(II), Pb(II), Cr(III) and Cr(VI) ions from aqueous solutions by adsorption was investigated. Batch adsorption experiments were conducted to observe the effect of pH (1-6) on the activated carbon. The adsorptions of these metals were found to be dependent on solution pH. Highest adsorption occurred at 1-2 for Cr(VI) and 3-6 for the rest of the metal ions, respectively. Adsorption capacities for the metal ions were obtained in the descending order of Cr(VI) > Cd(II) > Co(II) > Cr(III) > Ni(II) > Cu(II) > Pb(II) for the activated carbon prepared from apricot stone (ASAC).
A biosorbent, Neem leaf powder (NLP), was prepared from the mature leaves of the Azadirachta indica (Neem) tree by initial cleaning, drying, grinding, washing to remove pigments and redrying. The powder was characterized with respect to specific surface area (21.45 m2g(-1)), surface topography and surface functional groups and the material was used as an adsorbent in a batch process to remove Cd(II) from aqueous medium under conditions of different concentrations, NLP loadings, pH, agitation time and temperature. Adsorption increased from 8.8% at pH 4.0 to 70.0% at pH 7.0 and 93.6% at pH 9.5, the higher values in alkaline medium being due to removal by precipitation. The adsorption was very fast initially and maximum adsorption was observed within 300 min of agitation. The kinetics of the interactions was tested with pseudo first order Lagergren equation (mean k(1)=1.2x10(-2)min(-1)), simple second order kinetics (mean k2=1.34x10(-3) gmg(-1)min(-1)), Elovich equation, liquid film diffusion model (mean k=1.39x10(-2)min(-1)) and intra-particle diffusion mechanism. The adsorption data gave good fits with Langmuir and Freundlich isotherms and yielded Langmuir monolayer capacity of 158mgg(-1) for the NLP and Freundlich adsorption capacity of 18.7 Lg(-1). A 2.0 g of NLP could remove 86% of Cd(II) at 293 K from a solution containing 158.8 mg Cd(II) per litre. The mean values of the thermodynamic parameters, DeltaH, DeltaS and DeltaG, at 293 K were -73.7 kJmol(-1), -0.24 Jmol(-1)K(-1) and -3.63 kJmol(-1), respectively, showing the adsorption process to be thermodynamically favourable. The results have established good potentiality for the Neem leaf powder to be used as a biosorbent for Cd(II).
Grape bagasse generated in the wine production process was characterized through X-ray diffractometry, Fourier transform infrared spectroscopy, scanning electron microscopy, nuclear magnetic resonance and thermogravimetric analysis. The efficiency of this natural material for Cd(II) and Pb(II) adsorption was evaluated using a batch adsorption technique. Factors affecting metal adsorption such as pH and contact time were investigated. Maximum adsorption was found to occur at pH 7.0 and 3.0 for Cd(II) and Pb(II), respectively, and a contact time of 5min was required to reach equilibrium for both metals. With these conditions, adsorption studies were performed using a single solution. In addition, to calculate the adsorption capacities for each metal, the Langmüir isotherm model was used. The adsorption capacities were found to be 0.479 and 0.204mmolg(-1) for Cd(II) and Pb(II), respectively. The results showed that grape bagasse could be employed as a low-cost alternative adsorbent for effluent treatment.