Economical Sorbent Research Articles

Removal of cadmium (II) from aqueous effluents by sorption on Romanian silver fir tree bark (Abies alba Mill.) wastes

<p>In last decades the search for new low cost sorbents that have heavy metal ions binding capabilities is a hot topic in the field of clean-up technologies. In this study,  wastes of  Romanian silver tree (<em>Abies alba)</em> bark  were explored for first time as green and economical sorbent for the removal of Cd(II) ions from aqueous solutions.  The effect of various experimental parameters such as initial solution pH, sorbent dose, initial Cd(II) concentration, temperature and contact time has been investigated under batch conditions. </p> <p>The Langmuir and Freundlich models were used to describe the equilibrium isotherms and both models have been fitted very well. According to the evaluation using the Langmuir equation, the maximum sorption capacity of Cd (II) ions on <em>Abies alba</em> bark waste was found to be 11.98<br /> mg g<sup>-1</sup> at 293 K. The thermodynamic parameters showed that the process of Cd(II) sorption on silver fir tree bark was feasible, spontaneous and endothermic. Kinetic data were properly fitted with the pseudo–second order model. The obtained results strongly suggest that Romanian silver tree (<em>Abies alba)</em> bark is eligible as an efficient sorbent for the decontamination of toxic metals from wastewaters.</p>

Evaluation of Green Clover Leaves as Green and Economic Sorbent for Removal of High Levels of Iron from Different Water Sources

Evaluation of Green Clover Leaves as Green and Economic Sorbent for Removal of High Levels of Iron from Different Water Sources

Pulverized Banana Peel as an Economical Sorbent for the Preconcentration of Metals

A procedure for the determination of trace levels of Cd, Co, Cr, Fe, Mn, Ni, and Pb by flame atomic absorption spectrometry using a column preconcentration system is described in which the metals were adsorbed on pulverized banana peel, an economically and environmentally acceptable sorbent. In the optimization procedure, five variables (sample pH, mass of biosorbent, type of eluent, sample flow rate, and volume) were optimized and the capacity of the biosorbent was established. Under the optimized conditions, the detection limits of the method were 2.4, 27.0, 49.4, 31.1, 6.7, 29.6, and 46.2 µg L−1 for Cd, Co, Cr, Fe, Mn, Ni, and Pb, respectively. The precision, expressed as relative standard deviation, was less than 4% based on twelve measurements. The recoveries were 81.1% (Cd), 91.4% (Co), 87.2% (Cr), 90.1% (Fe), 88.0% (Mn), 94.1% (Ni), and 93.2% (Pb) under the optimum conditions (pH; 9, sample flow rate; 3 mL min−1, mass of biosorbent; 200 mg; eluent; 1 mol L−1 nitric acid, preconcentration factor; 10). The sorption capacity of pulverized banana peel was 15.12, 28.85, 32.70, 30.44, 30.94, 28.97, and 8.21 µmol per gram of adsorbent for Cd, Co, Cr, Fe, Mn, Ni, and Pb, respectively.

Study of hexamine removal by activated carbon modified with magnetic iron oxide nanoparticles for application in treatment of hexamine industrial wastewater

The industrial wastewater produced by hexamine plants is considered as a major environmental polluting factor, and hence its treatment is required. The adsorption of hexamine from aqueous solutions onto activated carbon modified with magnetic iron oxide nanoparticles (AC-MIONs) was studied in a batch process. Langmuir, Freundlich, and Toth isotherm models were used to fit the experimental data and then isotherm parameters were determined. The effects of activated carbon and AC-MIONs amounts, solution pH, contact time, temperature, and electrolyte concentration on the adsorption capacity were studied. The results indicate that AC-MIONs were a more efficient adsorbent for hexamine than activated carbon and have potential for the adsorption of hexamine from industrial hexamine wastewater. Pseudo-first order rate equation was able to provide realistic description of adsorption kinetics. The rate of adsorption process on AC-MIONs is higher than that on AC. Desorption of hexamine from AC-MIONs is easier than AC. Therefore, the AC-MIONs can be a good reusable and economical sorbent.

Application of Citrullus lanatus rind as biosorbent for removal of trivalent chromium from aqueous solution

Watermelon rind (WR) an agro waste was evaluated as an adsorbent for the removal of Cr3+ ions from aqueous solution. Batch mode adsorption studies were performed by varying parameters such as pH, contact time, adsorbent dose and initial metal ion concentration. Maximum loading capacity of WR was found to be 172.6mgg−1 for Cr3+ ions at pH 3. Kinetic studies show that removal of Cr3+ ions is rapid and follows a pseudosecond order model. Equilibrium data fit better with the Langmuir isotherm than the Freundlich isotherm. Thermodynamic parameters such as ΔG°, ΔH° and ΔS° were derived for the current system. The negative values of ΔG° show that the nature of sorption process is spontaneous. FTIR studies reveal that hydroxyl and carboxyl groups were responsible for uptake of metal ions. Successive desorption of Cr3+ ions reveals that WR can be an economical sorbent for the removal of heavy metals from aqueous solution. The results conclude that watermelon rind an agro waste can effectively be used for the removal of chromium ions from aqueous solution.

Adsorption and Dispersion of Nickel on Oil Palm Mesocarp Fiber

The investigation on the adsorption of metal from aqueous solution onto a biomass is important for several reasons. First, biomass has been widely used as an economical sorbent to remove heavy metals from industrial wastewater. Second, studies have shown that impregnation of metals onto a biomass helps improving thermal conversion of the biomass, for example, by reducing the yields of tar and char and thus enhancing the formation of syngas during biomass gasification. The produced metal-loaded char from thermal conversion of metal impregnated-biomass on the other hand, can be re-used as a catalyst for various reactions such as water-gas shift reaction. In this study, we examine the adsorption of Nickel from aqueous solution onto oil palm mesocarp fiber by varying important parameters such as pH and initial metal concentration. The kinetic study shows that the adsorption of Nickel follows the pseudo-second order kinetic model. Our study also reveals that Nickel disperses well into nano-size particles on the oil palm mesocarp fiber, suggesting the suitability for carrying out thermal conversion of Nickel-loaded oil palm mesocarp fiber in the future. The adsorption of Nickel is lower but sufficient enough to be used as catalyst in biomass thermochemical processes.

SUGARCANE BAGASSE AND MODIFIED RICE HUSK FOR THE REMOVAL OF MALACHITE GREEN FROM AQUEOUS WASTES

In this research, adsorption malachite green (MG) using Sugarcane bagasse (SB) and Rice husk (RH) were studied by batch method. Factors influencing dye adsorption such as the initial dye concentration, sorbent dosage, exposure time, temperature effect and pH, were investigated. The Langmuir, Freundich Temkin and Dubinin–Radushkevich (D-R) isotherms were used to fit the equilibrium data, and the results showed that the Freundlich and Langmuir model provided the best correlation of the experimental data for SB and RH, respectively. Adsorption kinetic data were tasted using pseudo-first-order, pseudo-second-order and intra particle diffusion models. It was observed that the pseudo-second-order kinetic equation could explain the biosorption kinetics of dye on both adsorbents and intra particle diffusion showed that dye adsorption was controlled by multi-adsorption stages with bagasse surface area. The results showed that both of them can be an economical sorbent for removal of dye from aqueous systems.

Potential of sawdust as a green and economical sorbent for simultaneous preconcentration of trace amounts of cadmium, cobalt, and lead from water, biological, food, and herbal samples.

Application of treated sawdust with NaOH as a green and economical sorbent for simultaneous preconcentration of trace amounts of Cd(II), Co(II), and Pb(II) ions from liver, lettuce, fish, and water as test samples with complicated matrices was investigated. Various parameters, such as effect of pH and contact time, breakthrough volume, type, and concentration of eluent and interference of ions were studied. The sorption was quantitative in the pH of 5.0 to 7.0 and desorption occurred instantaneously with 5.0mL of mixed solutions of ethanol and 2.0mol/L HNO3 -HCl and the amount of ions was measured by using flame atomic absorption spectrometry. Linearity was maintained at 3 to 500μg/L for cobalt, 5.0 to 800μg/L for lead, and 2.0 to 300μg/L for cadmium in the original solution. The relative standard deviation was less than 1.80% (n= 6, with concentration of 0.3mg/L for cadmium and 0.5mg/L for lead and cobalt). Detection limits and maximum capacity of the sorbent for Co (II), Cd (II), and Pb (II) in the original solution were 0.86, 0.50, and 1.7μg/L and 28.5, 30.6, and 47.3mg/g, respectively. The results for spiked real samples, effect of interfering ions, and adsorption capacity indicated that the applicability of this method for lead preconcentration is better than cadmium and cobalt preconcentration from complicated matrices. Practical Application: Sawdust can be applied as a green and economical sorbent for simultaneous preconcentration and solid-phase extraction of metal ions from food and environmental samples with complicated matrices.

Study of equilibrium and kinetic models for removal of chromium (VI) and lead (II) by modified feather by H<SUB align="right">2O<SUB align="right">2

Heavy metals are sorely toxic for the environment and human. In this study, the ability of feather for sorption chromium and lead from aqueous solution was investigated. All the experiments were carried out in a batch system. For this aim, the effect of various parameters such as pH, temperature, contact time, dosage sorbent and initial concentration were investigated. Results showed that maximum Cr (VI) and Pb adsorption were observed at pH 2 and pH 5, respectively. Also, the equilibrium time for Cr and Pb removal was archived 6 h and 8 h, respectively. Results also indicated that the adsorption efficiency decreased with increase in metals concentration. Experimental data were fitted with Freundlich and Langmuir isotherm models and also, experimental data was best fitted onto pseudo-second order model. The results indicate that ostrich feathers can be utilised as an economic and effective sorbent for Cr (VI) and Pb removal in water and industrial effluent.

Utilization of Scoria as PRB Reactive Media for the Removal of Petroleum Hydrocarbon from Groundwater

The aim of this study is to investigate the utilization of scoria as PRB reactive media for the removal of petroleum hydrocarbon from groundwater. Tests of comparison of scoria with powdered activated carbon(PAC) show that scoria has a larger capacity for petroleum hydrocarbon sorption than PAC. The particle size has weak effect on purification petroleum contaminated groundwater. The results of isothermal adsorption test show the high sorption capacity of the scoria(1.7g/g for TPH).The acquired sorption data are well fitted to the Langmuir isotherm.Careful examination of scoria’s composition and microstructure suggests that the sorption behavior is not only physical sorption but also chemical sorption,but mainly controlled by physical sorption .We recommend scoria as an economic,efficient and environmental friendly sorbent for petroleum hydrocarbon in contaminated groundwater.

Modified coconut shell fibers: A green and economical sorbent for the removal of anions from aqueous solutions

The powder of green coconut shell (Coco nuscifera L.) was chemically modified and used to remove inorganic anions from aqueous solution through batch process. The solid was modified with ammonium quaternary salt (2-hidroxypropyltrimethyl ammonium chloride) and characterized by a full factorial design. The FTIR, elemental analysis, SEM and X-ray measurements were performed. FTIR analysis indicated that the coconut bagasse interacted with NH2 groups of the surfactant. Initial anion concentration, pH and adsorbent dosage were investigated in this study, as well as the kinetics of adsorption and isotherms for the modified coconut bagasse. Kinetics of adsorption was examined by means of three kinetic models, i.e., pseudo-first-order, pseudo-second-order and intraparticle diffusion models. Pseudo-second-order kinetic model showed good agreement with the experimental data. Data on equilibrium were evaluated by using Langmuir, Freundlich, SIPS, Redlich–Peterson, Temkin models. It was observed that the experimental data fits well to Langmuir, SIPS, and Redlich–Peterson equations. The results indicated that the modified coconut powder exhibited potential application for removal of nitrate, sulfate and phosphate from aqueous solutions.

REMOVAL OF Cd(II) IONS FROM AQUEOUS SOLUTION BY RETENTION ON PINE BARK

Among the different types of waste products tested, the bark of different Pinus species have been identified as a promising class of low- cost sorbents for heavy metal binding. In this context, the potential of Romanian pine bark wastes as green and economical sorbent for cadmium (II) ions removal from aqueous solutions has been tested in batch conditions as function of initial pH, contact time, sorbent dose, metal ion concentration and temperature. The equilibrium data at three different temperatures were processed using the Langmuir isotherm model. The monolayer Cd(II) sorption capacity of Pinus sylvestris L. bark is not very high, however quite sufficient for waste materials. The thermodynamic parameters of Cd(II) sorption process on pine bark were also evaluated based on the Langmuir constant. From present work it is obvious that an unused resources like pine bark waste under study can be regarded as Cd(II) remover from wastewaters and industrial effluents to overcome water pollution.

Adsorption kinetics, capacity and mechanism of arsenate and phosphate on a bifunctional TiO 2–Fe 2O 3 bi-composite

Mixed oxide TiO 2–Fe 2O 3 bi-composites have been recognised as efficient and economical sorbents with great promise for arsenic removal from groundwater. In this study, we use a fast, simple and inexpensive synthesis method for this type of bi-composite and assess its adsorption performance. The kinetics of arsenate and phosphate adsorption onto the bi-composite are determined, demonstrating rapid and stable uptake of both oxy-anions over several days and with improved performance compared to the widely used TiO 2 sorbent. A modified pseudo-second order rate equation is introduced, which allows the adsorption kinetics to be modelled as two simultaneous, parallel reaction pathways with separate kinetic parameters. This equation reproduces the experimental observations accurately across a wide range of timescales from minutes to days. Our experimental data agrees with previous interpretations of the adsorption mechanism including the formation of mono-dentate and bi-dentate inner-sphere surface complexes. The arsenate and phosphate uptake capacities of the bi-composite are reported. Equilibrium studies were conducted between pH 5 and 9 and interpreted within the Langmuir, Freundlich and Dubinin–Radushkevich isotherm models.

Measurement of Mercury in Flue Gas Based on an Aluminum Matrix Sorbent

The measurement of total mercury in flue gas based on an economical aluminum matrix sorbent was developed in this paper. A sorbent trap consisted of three tubes was employed to capture Hg from flue gas. Hg trapped on sorbent was transferred into solution by acid leaching and then detected by CVAAS. Hg adsorbed on sorbent was recovered completely by leaching process. The 87.7% recovery of Hg in flue gas by tube 1 and tube 2 was obtained on the equipment of coal combustion and sampling in lab. In order to evaluate the ability to recover and accurately quantify Hg0 on the sorbent media, the analytical bias test on tube 3 spiked with Hg0 was also performed and got the average recovery of 97.1%. Mercury measurements based on this method were conducted for three coal-fired power plants in China. The mercury in coal is distributed into bottom ash, electrostatic precipitator (ESP) ash, wet flue gas desulfurization (WFGD) reactant, and flue gas, and the relative distribution varied depending on factors such as the coal type and the operation conditions of plants. The mercury mass balances of three plants were also calculated which were 91.6%, 77.1%, and 118%, respectively. The reliability of this method was verified by the Ontario Hydro (OH) method either in lab or in field.

Biosorption of Trivalent Chromium from Aqueous Solution by Red Seaweed Polysiphonia nigrescens

This paper presents the biosorption of chromium onto red seaweed (Polysiphonia nigrescens). Batch mode experiments were performed to determine experimental parameters affecting sorption process such as pH, contact time, initial metal ion concentration and biomass dosage. The Cr(III) sorption was dependent on pH and adsorbent dosage. The adsorption kinetic data could be fitted with a pseudo-second-order model and the equilibrium data with a Langmuir model. The maximum sorption capacity was of 16.11 mg/g at pH 4 and 10 g/L of biomass dosage. 0.1 M H2SO4 showed good desorption efficiency (>80%). Spectroscopy analysis showed that Cr(III) sorption on seaweed was mainly through the ion-exchange mechanism. This report indicates that P. nigrescens is an effective and economical sorbent for removal of Cr(III) from wastewaters.

Sorption characteristics of an economical sorbent material used for removal radioisotopes of cesium and europium

Application study for the evaluation of sorption characteristics of sawdust as an economical sorbent material used for decontamination of radioisotopes cesium and europium from aqueous solution has been carried out in the present work. In this respect, sawdust (untreated and treated by HNO3) has been prepared from the commercial processing of wood for furniture production. Pore properties of the activated carbon such as BET surface area, pore volume, pore size distribution, and pore diameter were characterized by N2 adsorption and DFT software. Radiotracer method onto sawdust from aqueous solutions was studied in a batch technique with respect to pH, contact time, temperature. The kinetics of adsorption of Eu3+ and Cs+ have been discussed using five kinetic models namely, pseudo-first-order model, pseudo-second-order model, Elovich equation, intraparticle diffusion model, and modified Freundlich equation that have been tested in order to analysis the experimental data. Kinetic parameters and correlation coefficients were determined. It was shown that the second-order kinetic equation could describe the sorption kinetics for two metal ions. The metal uptake process was found to be controlled by intraparticle diffusion. Thermodynamic parameters, such as ΔH, ΔG and ΔS, have been calculated by using the thermodynamic equilibrium coefficient obtained at different temperatures. The obtained results indicated that endothermic nature of sorption process for both 152+154Eu and 134Cs onto sawdust.

Banana peel: A green and economical sorbent for the selective removal of Cr(VI) from industrial wastewater

This study describes the use of banana peel, a commonly produced fruit waste, for the removal of Cr(VI) from industrial wastewater. The parameters pH, contact time, initial metal ion concentration, and temperature were investigated and the conditions resulting in rapid and efficient adsorption (95% within 10 min) were determined. The binding of metal ions was found to be pH dependent with the optimal sorption occurring at pH 2. The retained species were eluted with 5 mL of 2 M H 2SO 4. To elucidate the mechanism of the process, total amounts of chromium and Cr(VI) were analyzed using flame atomic absorption and ultraviolet–visible (UV–vis) spectroscopic techniques, respectively. The Langmuir and Dubinin–Radushkevich (D–R) isotherms were used to describe the partitioning behavior for the system at different temperatures. Kinetics and thermodynamics of Cr(VI) removal by banana peel were also studied. The influence of diverse ions on the sorption behavior revealed that only Fe(II) ions (of those tested) suppressed the sorption of Cr(VI) ions to some extent. The method was applied for the removal of Cr(VI) from industrial wastewater.

TRACE ELEMENTS REMOVAL FROM WATER USING MODIFIED ACTIVATED CARBON

This paper present the possible alternative options for the remove of trace elements from drinking water supplies in the trace. Arsenic and chromium are two of the most toxic pollutants, introduced into natural waters from a variety of sources and causing various adverse effects on living bodies. The performance of three filter bed methods was evaluated in the laboratory. Experiments were conducted to investigate the sorption of arsenic and chromium on carbon steel and removal of trace elements from drinking water with a household filtration process. The affinity of the arsenic and chromium species for Fe/Fe3C (iron/iron carbide) sites is the key factor controlling the removal of the elements. The method is based on the use of powdered block carbon, powder carbon steel and ceramic spheres in the ion‐sorption columns as a cleaning process. The modified powdered block carbon is a satisfactory and economical sorbent for trace elements (arsenite and chromate) dissolved in water due to its low unit cost of about $ 23 and compatibility with the traditional household filtration system.

Sawdust: A green and economical sorbent for thallium removal

Removal/preconcentration of thallium(I) ions from aqueous solution by sawdust; a waste material derived from the commercial processing of Cedrus Deodar wood for furniture production was investigated. A simple and low-cost modification results in increasing the sorption capacity of raw sawdust from 2.71 to 13.18 mg g −1 . Sorption was found to be rapid (∼98% within 8 min). The binding of metal ions was found to be pH dependent, optimal sorption accruing at around pH 6–9. Potentiometeric titrations of sawdust revealed two distinct p K a values, the first having the value similar to carboxylic groups (3.3–4.8) and second comparable with that of amines (8.53–10.2) with the surface site densities of 1.99 × 10 −4 and 7.94 × 10 −5 mol g −1 , respectively. Retained Tl(I) ions were eluted with 5 ml 0.1 mol l −1 HCl. Detection limit of 0.0125 μg ml −1 was achieved with an enrichment factor of 160. Recovery was quantitative using sample volume of 800 ml. The Langmuir, Freundlich and D–R isotherm equations were used to describe partitioning behavior for the system at different temperatures. Kinetic and thermodynamic behavior of sawdust for Tl(I) ions removal was also studied.

Sawdust—A green and economical sorbent for the removal of cadmium (II) ions

The ability of sawdust (treated and untreated) waste, a waste material derived from the commercial processing of cedrus deodar wood for furniture production, to remove/preconcentrate Cd(II) ions from aqueous solution was determined. Sorption was found to be rapid (∼97% within 8 min). The binding of metal ions was found to be pH dependent, optimal sorption accruing at around pH 4–8. Potentiometric titrations of sawdust revealed two distinct p K a values, the first having the value similar to carboxylic groups (3.3–4.8) and second comparable with that of amines (8.53–10.2) with the densities 1.99 × 10 −4 and 7.94 × 10 −5, respectively. Retained Cd(II) ions were eluted with 5 ml of 0.1 mol l −1 HCl. Detection limit of 0.016 μg ml −1 was achieved with enrichment factors of 120. Recovery was quantitative using sample volume of 600 ml. The Langmuir and D–R isotherm equations were used to describe partitioning behavior for the system at different temperatures. Kinetic and thermodynamic behavior of sawdust for Cd(II) ions removal was also studied.